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	Version: linux-6.0.1 spark-3.0.0 hadoop-3.2.0-src hadoop-3.3.0-src spark-2.4.7 linux-4.15.13 hadoop-2.7.4-src Revert   Change

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * Implementation of the security services.
  *
  * Authors : Stephen Smalley, <sds@tycho.nsa.gov>
  *       James Morris <jmorris@redhat.com>
  *
  * Updated: Trusted Computer Solutions, Inc. <dgoeddel@trustedcs.com>
  *
  *  Support for enhanced MLS infrastructure.
  *  Support for context based audit filters.
  *
  * Updated: Frank Mayer <mayerf@tresys.com> and Karl MacMillan <kmacmillan@tresys.com>
  *
  *  Added conditional policy language extensions
  *
  * Updated: Hewlett-Packard <paul@paul-moore.com>
  *
  *      Added support for NetLabel
  *      Added support for the policy capability bitmap
  *
  * Updated: Chad Sellers <csellers@tresys.com>
  *
  *  Added validation of kernel classes and permissions
  *
  * Updated: KaiGai Kohei <kaigai@ak.jp.nec.com>
  *
  *  Added support for bounds domain and audit messaged on masked permissions
  *
  * Updated: Guido Trentalancia <guido@trentalancia.com>
  *
  *  Added support for runtime switching of the policy type
  *
  * Copyright (C) 2008, 2009 NEC Corporation
  * Copyright (C) 2006, 2007 Hewlett-Packard Development Company, L.P.
  * Copyright (C) 2004-2006 Trusted Computer Solutions, Inc.
  * Copyright (C) 2003 - 2004, 2006 Tresys Technology, LLC
  * Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com>
  */
 #include <linux/kernel.h>
 #include <linux/slab.h>
 #include <linux/string.h>
 #include <linux/spinlock.h>
 #include <linux/rcupdate.h>
 #include <linux/errno.h>
 #include <linux/in.h>
 #include <linux/sched.h>
 #include <linux/audit.h>
 #include <linux/vmalloc.h>
 #include <linux/lsm_hooks.h>
 #include <net/netlabel.h>
 
 #include "flask.h"
 #include "avc.h"
 #include "avc_ss.h"
 #include "security.h"
 #include "context.h"
 #include "policydb.h"
 #include "sidtab.h"
 #include "services.h"
 #include "conditional.h"
 #include "mls.h"
 #include "objsec.h"
 #include "netlabel.h"
 #include "xfrm.h"
 #include "ebitmap.h"
 #include "audit.h"
 #include "policycap_names.h"
 #include "ima.h"
 
 struct convert_context_args {
     struct selinux_state *state;
     struct policydb *oldp;
     struct policydb *newp;
 };
 
 struct selinux_policy_convert_data {
     struct convert_context_args args;
     struct sidtab_convert_params sidtab_params;
 };
 
 /* Forward declaration. */
 static int context_struct_to_string(struct policydb *policydb,
                     struct context *context,
                     char **scontext,
                     u32 *scontext_len);
 
 static int sidtab_entry_to_string(struct policydb *policydb,
                   struct sidtab *sidtab,
                   struct sidtab_entry *entry,
                   char **scontext,
                   u32 *scontext_len);
 
 static void context_struct_compute_av(struct policydb *policydb,
                       struct context *scontext,
                       struct context *tcontext,
                       u16 tclass,
                       struct av_decision *avd,
                       struct extended_perms *xperms);
 
 static int selinux_set_mapping(struct policydb *pol,
                    const struct security_class_mapping *map,
                    struct selinux_map *out_map)
 {
     u16 i, j;
     unsigned k;
     bool print_unknown_handle = false;
 
     /* Find number of classes in the input mapping */
     if (!map)
         return -EINVAL;
     i = 0;
     while (map[i].name)
         i++;
 
     /* Allocate space for the class records, plus one for class zero */
     out_map->mapping = kcalloc(++i, sizeof(*out_map->mapping), GFP_ATOMIC);
     if (!out_map->mapping)
         return -ENOMEM;
 
     /* Store the raw class and permission values */
     j = 0;
     while (map[j].name) {
         const struct security_class_mapping *p_in = map + (j++);
         struct selinux_mapping *p_out = out_map->mapping + j;
 
         /* An empty class string skips ahead */
         if (!strcmp(p_in->name, "")) {
             p_out->num_perms = 0;
             continue;
         }
 
         p_out->value = string_to_security_class(pol, p_in->name);
         if (!p_out->value) {
             pr_info("SELinux:  Class %s not defined in policy.\n",
                    p_in->name);
             if (pol->reject_unknown)
                 goto err;
             p_out->num_perms = 0;
             print_unknown_handle = true;
             continue;
         }
 
         k = 0;
         while (p_in->perms[k]) {
             /* An empty permission string skips ahead */
             if (!*p_in->perms[k]) {
                 k++;
                 continue;
             }
             p_out->perms[k] = string_to_av_perm(pol, p_out->value,
                                 p_in->perms[k]);
             if (!p_out->perms[k]) {
                 pr_info("SELinux:  Permission %s in class %s not defined in policy.\n",
                        p_in->perms[k], p_in->name);
                 if (pol->reject_unknown)
                     goto err;
                 print_unknown_handle = true;
             }
 
             k++;
         }
         p_out->num_perms = k;
     }
 
     if (print_unknown_handle)
         pr_info("SELinux: the above unknown classes and permissions will be %s\n",
                pol->allow_unknown ? "allowed" : "denied");
 
     out_map->size = i;
     return 0;
 err:
     kfree(out_map->mapping);
     out_map->mapping = NULL;
     return -EINVAL;
 }
 
 /*
  * Get real, policy values from mapped values
  */
 
 static u16 unmap_class(struct selinux_map *map, u16 tclass)
 {
     if (tclass < map->size)
         return map->mapping[tclass].value;
 
     return tclass;
 }
 
 /*
  * Get kernel value for class from its policy value
  */
 static u16 map_class(struct selinux_map *map, u16 pol_value)
 {
     u16 i;
 
     for (i = 1; i < map->size; i++) {
         if (map->mapping[i].value == pol_value)
             return i;
     }
 
     return SECCLASS_NULL;
 }
 
 static void map_decision(struct selinux_map *map,
              u16 tclass, struct av_decision *avd,
              int allow_unknown)
 {
     if (tclass < map->size) {
         struct selinux_mapping *mapping = &map->mapping[tclass];
         unsigned int i, n = mapping->num_perms;
         u32 result;
 
         for (i = 0, result = 0; i < n; i++) {
             if (avd->allowed & mapping->perms[i])
                 result |= 1<<i;
             if (allow_unknown && !mapping->perms[i])
                 result |= 1<<i;
         }
         avd->allowed = result;
 
         for (i = 0, result = 0; i < n; i++)
             if (avd->auditallow & mapping->perms[i])
                 result |= 1<<i;
         avd->auditallow = result;
 
         for (i = 0, result = 0; i < n; i++) {
             if (avd->auditdeny & mapping->perms[i])
                 result |= 1<<i;
             if (!allow_unknown && !mapping->perms[i])
                 result |= 1<<i;
         }
         /*
          * In case the kernel has a bug and requests a permission
          * between num_perms and the maximum permission number, we
          * should audit that denial
          */
         for (; i < (sizeof(u32)*8); i++)
             result |= 1<<i;
         avd->auditdeny = result;
     }
 }
 
 int security_mls_enabled(struct selinux_state *state)
 {
     int mls_enabled;
     struct selinux_policy *policy;
 
     if (!selinux_initialized(state))
         return 0;
 
     rcu_read_lock();
     policy = rcu_dereference(state->policy);
     mls_enabled = policy->policydb.mls_enabled;
     rcu_read_unlock();
     return mls_enabled;
 }
 
 /*
  * Return the boolean value of a constraint expression
  * when it is applied to the specified source and target
  * security contexts.
  *
  * xcontext is a special beast...  It is used by the validatetrans rules
  * only.  For these rules, scontext is the context before the transition,
  * tcontext is the context after the transition, and xcontext is the context
  * of the process performing the transition.  All other callers of
  * constraint_expr_eval should pass in NULL for xcontext.
  */
 static int constraint_expr_eval(struct policydb *policydb,
                 struct context *scontext,
                 struct context *tcontext,
                 struct context *xcontext,
                 struct constraint_expr *cexpr)
 {
     u32 val1, val2;
     struct context *c;
     struct role_datum *r1, *r2;
     struct mls_level *l1, *l2;
     struct constraint_expr *e;
     int s[CEXPR_MAXDEPTH];
     int sp = -1;
 
     for (e = cexpr; e; e = e->next) {
         switch (e->expr_type) {
         case CEXPR_NOT:
             BUG_ON(sp < 0);
             s[sp] = !s[sp];
             break;
         case CEXPR_AND:
             BUG_ON(sp < 1);
             sp--;
             s[sp] &= s[sp + 1];
             break;
         case CEXPR_OR:
             BUG_ON(sp < 1);
             sp--;
             s[sp] |= s[sp + 1];
             break;
         case CEXPR_ATTR:
             if (sp == (CEXPR_MAXDEPTH - 1))
                 return 0;
             switch (e->attr) {
             case CEXPR_USER:
                 val1 = scontext->user;
                 val2 = tcontext->user;
                 break;
             case CEXPR_TYPE:
                 val1 = scontext->type;
                 val2 = tcontext->type;
                 break;
             case CEXPR_ROLE:
                 val1 = scontext->role;
                 val2 = tcontext->role;
                 r1 = policydb->role_val_to_struct[val1 - 1];
                 r2 = policydb->role_val_to_struct[val2 - 1];
                 switch (e->op) {
                 case CEXPR_DOM:
                     s[++sp] = ebitmap_get_bit(&r1->dominates,
                                   val2 - 1);
                     continue;
                 case CEXPR_DOMBY:
                     s[++sp] = ebitmap_get_bit(&r2->dominates,
                                   val1 - 1);
                     continue;
                 case CEXPR_INCOMP:
                     s[++sp] = (!ebitmap_get_bit(&r1->dominates,
                                     val2 - 1) &&
                            !ebitmap_get_bit(&r2->dominates,
                                     val1 - 1));
                     continue;
                 default:
                     break;
                 }
                 break;
             case CEXPR_L1L2:
                 l1 = &(scontext->range.level[0]);
                 l2 = &(tcontext->range.level[0]);
                 goto mls_ops;
             case CEXPR_L1H2:
                 l1 = &(scontext->range.level[0]);
                 l2 = &(tcontext->range.level[1]);
                 goto mls_ops;
             case CEXPR_H1L2:
                 l1 = &(scontext->range.level[1]);
                 l2 = &(tcontext->range.level[0]);
                 goto mls_ops;
             case CEXPR_H1H2:
                 l1 = &(scontext->range.level[1]);
                 l2 = &(tcontext->range.level[1]);
                 goto mls_ops;
             case CEXPR_L1H1:
                 l1 = &(scontext->range.level[0]);
                 l2 = &(scontext->range.level[1]);
                 goto mls_ops;
             case CEXPR_L2H2:
                 l1 = &(tcontext->range.level[0]);
                 l2 = &(tcontext->range.level[1]);
                 goto mls_ops;
 mls_ops:
                 switch (e->op) {
                 case CEXPR_EQ:
                     s[++sp] = mls_level_eq(l1, l2);
                     continue;
                 case CEXPR_NEQ:
                     s[++sp] = !mls_level_eq(l1, l2);
                     continue;
                 case CEXPR_DOM:
                     s[++sp] = mls_level_dom(l1, l2);
                     continue;
                 case CEXPR_DOMBY:
                     s[++sp] = mls_level_dom(l2, l1);
                     continue;
                 case CEXPR_INCOMP:
                     s[++sp] = mls_level_incomp(l2, l1);
                     continue;
                 default:
                     BUG();
                     return 0;
                 }
                 break;
             default:
                 BUG();
                 return 0;
             }
 
             switch (e->op) {
             case CEXPR_EQ:
                 s[++sp] = (val1 == val2);
                 break;
             case CEXPR_NEQ:
                 s[++sp] = (val1 != val2);
                 break;
             default:
                 BUG();
                 return 0;
             }
             break;
         case CEXPR_NAMES:
             if (sp == (CEXPR_MAXDEPTH-1))
                 return 0;
             c = scontext;
             if (e->attr & CEXPR_TARGET)
                 c = tcontext;
             else if (e->attr & CEXPR_XTARGET) {
                 c = xcontext;
                 if (!c) {
                     BUG();
                     return 0;
                 }
             }
             if (e->attr & CEXPR_USER)
                 val1 = c->user;
             else if (e->attr & CEXPR_ROLE)
                 val1 = c->role;
             else if (e->attr & CEXPR_TYPE)
                 val1 = c->type;
             else {
                 BUG();
                 return 0;
             }
 
             switch (e->op) {
             case CEXPR_EQ:
                 s[++sp] = ebitmap_get_bit(&e->names, val1 - 1);
                 break;
             case CEXPR_NEQ:
                 s[++sp] = !ebitmap_get_bit(&e->names, val1 - 1);
                 break;
             default:
                 BUG();
                 return 0;
             }
             break;
         default:
             BUG();
             return 0;
         }
     }
 
     BUG_ON(sp != 0);
     return s[0];
 }
 
 /*
  * security_dump_masked_av - dumps masked permissions during
  * security_compute_av due to RBAC, MLS/Constraint and Type bounds.
  */
 static int dump_masked_av_helper(void *k, void *d, void *args)
 {
     struct perm_datum *pdatum = d;
     char **permission_names = args;
 
     BUG_ON(pdatum->value < 1 || pdatum->value > 32);
 
     permission_names[pdatum->value - 1] = (char *)k;
 
     return 0;
 }
 
 static void security_dump_masked_av(struct policydb *policydb,
                     struct context *scontext,
                     struct context *tcontext,
                     u16 tclass,
                     u32 permissions,
                     const char *reason)
 {
     struct common_datum *common_dat;
     struct class_datum *tclass_dat;
     struct audit_buffer *ab;
     char *tclass_name;
     char *scontext_name = NULL;
     char *tcontext_name = NULL;
     char *permission_names[32];
     int index;
     u32 length;
     bool need_comma = false;
 
     if (!permissions)
         return;
 
     tclass_name = sym_name(policydb, SYM_CLASSES, tclass - 1);
     tclass_dat = policydb->class_val_to_struct[tclass - 1];
     common_dat = tclass_dat->comdatum;
 
     /* init permission_names */
     if (common_dat &&
         hashtab_map(&common_dat->permissions.table,
             dump_masked_av_helper, permission_names) < 0)
         goto out;
 
     if (hashtab_map(&tclass_dat->permissions.table,
             dump_masked_av_helper, permission_names) < 0)
         goto out;
 
     /* get scontext/tcontext in text form */
     if (context_struct_to_string(policydb, scontext,
                      &scontext_name, &length) < 0)
         goto out;
 
     if (context_struct_to_string(policydb, tcontext,
                      &tcontext_name, &length) < 0)
         goto out;
 
     /* audit a message */
     ab = audit_log_start(audit_context(),
                  GFP_ATOMIC, AUDIT_SELINUX_ERR);
     if (!ab)
         goto out;
 
     audit_log_format(ab, "op=security_compute_av reason=%s "
              "scontext=%s tcontext=%s tclass=%s perms=",
              reason, scontext_name, tcontext_name, tclass_name);
 
     for (index = 0; index < 32; index++) {
         u32 mask = (1 << index);
 
         if ((mask & permissions) == 0)
             continue;
 
         audit_log_format(ab, "%s%s",
                  need_comma ? "," : "",
                  permission_names[index]
                  ? permission_names[index] : "????");
         need_comma = true;
     }
     audit_log_end(ab);
 out:
     /* release scontext/tcontext */
     kfree(tcontext_name);
     kfree(scontext_name);
 }
 
 /*
  * security_boundary_permission - drops violated permissions
  * on boundary constraint.
  */
 static void type_attribute_bounds_av(struct policydb *policydb,
                      struct context *scontext,
                      struct context *tcontext,
                      u16 tclass,
                      struct av_decision *avd)
 {
     struct context lo_scontext;
     struct context lo_tcontext, *tcontextp = tcontext;
     struct av_decision lo_avd;
     struct type_datum *source;
     struct type_datum *target;
     u32 masked = 0;
 
     source = policydb->type_val_to_struct[scontext->type - 1];
     BUG_ON(!source);
 
     if (!source->bounds)
         return;
 
     target = policydb->type_val_to_struct[tcontext->type - 1];
     BUG_ON(!target);
 
     memset(&lo_avd, 0, sizeof(lo_avd));
 
     memcpy(&lo_scontext, scontext, sizeof(lo_scontext));
     lo_scontext.type = source->bounds;
 
     if (target->bounds) {
         memcpy(&lo_tcontext, tcontext, sizeof(lo_tcontext));
         lo_tcontext.type = target->bounds;
         tcontextp = &lo_tcontext;
     }
 
     context_struct_compute_av(policydb, &lo_scontext,
                   tcontextp,
                   tclass,
                   &lo_avd,
                   NULL);
 
     masked = ~lo_avd.allowed & avd->allowed;
 
     if (likely(!masked))
         return;     /* no masked permission */
 
     /* mask violated permissions */
     avd->allowed &= ~masked;
 
     /* audit masked permissions */
     security_dump_masked_av(policydb, scontext, tcontext,
                 tclass, masked, "bounds");
 }
 
 /*
  * flag which drivers have permissions
  * only looking for ioctl based extended permssions
  */
 void services_compute_xperms_drivers(
         struct extended_perms *xperms,
         struct avtab_node *node)
 {
     unsigned int i;
 
     if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
         /* if one or more driver has all permissions allowed */
         for (i = 0; i < ARRAY_SIZE(xperms->drivers.p); i++)
             xperms->drivers.p[i] |= node->datum.u.xperms->perms.p[i];
     } else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
         /* if allowing permissions within a driver */
         security_xperm_set(xperms->drivers.p,
                     node->datum.u.xperms->driver);
     }
 
     xperms->len = 1;
 }
 
 /*
  * Compute access vectors and extended permissions based on a context
  * structure pair for the permissions in a particular class.
  */
 static void context_struct_compute_av(struct policydb *policydb,
                       struct context *scontext,
                       struct context *tcontext,
                       u16 tclass,
                       struct av_decision *avd,
                       struct extended_perms *xperms)
 {
     struct constraint_node *constraint;
     struct role_allow *ra;
     struct avtab_key avkey;
     struct avtab_node *node;
     struct class_datum *tclass_datum;
     struct ebitmap *sattr, *tattr;
     struct ebitmap_node *snode, *tnode;
     unsigned int i, j;
 
     avd->allowed = 0;
     avd->auditallow = 0;
     avd->auditdeny = 0xffffffff;
     if (xperms) {
         memset(&xperms->drivers, 0, sizeof(xperms->drivers));
         xperms->len = 0;
     }
 
     if (unlikely(!tclass || tclass > policydb->p_classes.nprim)) {
         if (printk_ratelimit())
             pr_warn("SELinux:  Invalid class %hu\n", tclass);
         return;
     }
 
     tclass_datum = policydb->class_val_to_struct[tclass - 1];
 
     /*
      * If a specific type enforcement rule was defined for
      * this permission check, then use it.
      */
     avkey.target_class = tclass;
     avkey.specified = AVTAB_AV | AVTAB_XPERMS;
     sattr = &policydb->type_attr_map_array[scontext->type - 1];
     tattr = &policydb->type_attr_map_array[tcontext->type - 1];
     ebitmap_for_each_positive_bit(sattr, snode, i) {
         ebitmap_for_each_positive_bit(tattr, tnode, j) {
             avkey.source_type = i + 1;
             avkey.target_type = j + 1;
             for (node = avtab_search_node(&policydb->te_avtab,
                               &avkey);
                  node;
                  node = avtab_search_node_next(node, avkey.specified)) {
                 if (node->key.specified == AVTAB_ALLOWED)
                     avd->allowed |= node->datum.u.data;
                 else if (node->key.specified == AVTAB_AUDITALLOW)
                     avd->auditallow |= node->datum.u.data;
                 else if (node->key.specified == AVTAB_AUDITDENY)
                     avd->auditdeny &= node->datum.u.data;
                 else if (xperms && (node->key.specified & AVTAB_XPERMS))
                     services_compute_xperms_drivers(xperms, node);
             }
 
             /* Check conditional av table for additional permissions */
             cond_compute_av(&policydb->te_cond_avtab, &avkey,
                     avd, xperms);
 
         }
     }
 
     /*
      * Remove any permissions prohibited by a constraint (this includes
      * the MLS policy).
      */
     constraint = tclass_datum->constraints;
     while (constraint) {
         if ((constraint->permissions & (avd->allowed)) &&
             !constraint_expr_eval(policydb, scontext, tcontext, NULL,
                       constraint->expr)) {
             avd->allowed &= ~(constraint->permissions);
         }
         constraint = constraint->next;
     }
 
     /*
      * If checking process transition permission and the
      * role is changing, then check the (current_role, new_role)
      * pair.
      */
     if (tclass == policydb->process_class &&
         (avd->allowed & policydb->process_trans_perms) &&
         scontext->role != tcontext->role) {
         for (ra = policydb->role_allow; ra; ra = ra->next) {
             if (scontext->role == ra->role &&
                 tcontext->role == ra->new_role)
                 break;
         }
         if (!ra)
             avd->allowed &= ~policydb->process_trans_perms;
     }
 
     /*
      * If the given source and target types have boundary
      * constraint, lazy checks have to mask any violated
      * permission and notice it to userspace via audit.
      */
     type_attribute_bounds_av(policydb, scontext, tcontext,
                  tclass, avd);
 }
 
 static int security_validtrans_handle_fail(struct selinux_state *state,
                     struct selinux_policy *policy,
                     struct sidtab_entry *oentry,
                     struct sidtab_entry *nentry,
                     struct sidtab_entry *tentry,
                     u16 tclass)
 {
     struct policydb *p = &policy->policydb;
     struct sidtab *sidtab = policy->sidtab;
     char *o = NULL, *n = NULL, *t = NULL;
     u32 olen, nlen, tlen;
 
     if (sidtab_entry_to_string(p, sidtab, oentry, &o, &olen))
         goto out;
     if (sidtab_entry_to_string(p, sidtab, nentry, &n, &nlen))
         goto out;
     if (sidtab_entry_to_string(p, sidtab, tentry, &t, &tlen))
         goto out;
     audit_log(audit_context(), GFP_ATOMIC, AUDIT_SELINUX_ERR,
           "op=security_validate_transition seresult=denied"
           " oldcontext=%s newcontext=%s taskcontext=%s tclass=%s",
           o, n, t, sym_name(p, SYM_CLASSES, tclass-1));
 out:
     kfree(o);
     kfree(n);
     kfree(t);
 
     if (!enforcing_enabled(state))
         return 0;
     return -EPERM;
 }
 
 static int security_compute_validatetrans(struct selinux_state *state,
                       u32 oldsid, u32 newsid, u32 tasksid,
                       u16 orig_tclass, bool user)
 {
     struct selinux_policy *policy;
     struct policydb *policydb;
     struct sidtab *sidtab;
     struct sidtab_entry *oentry;
     struct sidtab_entry *nentry;
     struct sidtab_entry *tentry;
     struct class_datum *tclass_datum;
     struct constraint_node *constraint;
     u16 tclass;
     int rc = 0;
 
 
     if (!selinux_initialized(state))
         return 0;
 
     rcu_read_lock();
 
     policy = rcu_dereference(state->policy);
     policydb = &policy->policydb;
     sidtab = policy->sidtab;
 
     if (!user)
         tclass = unmap_class(&policy->map, orig_tclass);
     else
         tclass = orig_tclass;
 
     if (!tclass || tclass > policydb->p_classes.nprim) {
         rc = -EINVAL;
         goto out;
     }
     tclass_datum = policydb->class_val_to_struct[tclass - 1];
 
     oentry = sidtab_search_entry(sidtab, oldsid);
     if (!oentry) {
         pr_err("SELinux: %s:  unrecognized SID %d\n",
             __func__, oldsid);
         rc = -EINVAL;
         goto out;
     }
 
     nentry = sidtab_search_entry(sidtab, newsid);
     if (!nentry) {
         pr_err("SELinux: %s:  unrecognized SID %d\n",
             __func__, newsid);
         rc = -EINVAL;
         goto out;
     }
 
     tentry = sidtab_search_entry(sidtab, tasksid);
     if (!tentry) {
         pr_err("SELinux: %s:  unrecognized SID %d\n",
             __func__, tasksid);
         rc = -EINVAL;
         goto out;
     }
 
     constraint = tclass_datum->validatetrans;
     while (constraint) {
         if (!constraint_expr_eval(policydb, &oentry->context,
                       &nentry->context, &tentry->context,
                       constraint->expr)) {
             if (user)
                 rc = -EPERM;
             else
                 rc = security_validtrans_handle_fail(state,
                                 policy,
                                 oentry,
                                 nentry,
                                 tentry,
                                 tclass);
             goto out;
         }
         constraint = constraint->next;
     }
 
 out:
     rcu_read_unlock();
     return rc;
 }
 
 int security_validate_transition_user(struct selinux_state *state,
                       u32 oldsid, u32 newsid, u32 tasksid,
                       u16 tclass)
 {
     return security_compute_validatetrans(state, oldsid, newsid, tasksid,
                           tclass, true);
 }
 
 int security_validate_transition(struct selinux_state *state,
                  u32 oldsid, u32 newsid, u32 tasksid,
                  u16 orig_tclass)
 {
     return security_compute_validatetrans(state, oldsid, newsid, tasksid,
                           orig_tclass, false);
 }
 
 /*
  * security_bounded_transition - check whether the given
  * transition is directed to bounded, or not.
  * It returns 0, if @newsid is bounded by @oldsid.
  * Otherwise, it returns error code.
  *
  * @state: SELinux state
  * @oldsid : current security identifier
  * @newsid : destinated security identifier
  */
 int security_bounded_transition(struct selinux_state *state,
                 u32 old_sid, u32 new_sid)
 {
     struct selinux_policy *policy;
     struct policydb *policydb;
     struct sidtab *sidtab;
     struct sidtab_entry *old_entry, *new_entry;
     struct type_datum *type;
     int index;
     int rc;
 
     if (!selinux_initialized(state))
         return 0;
 
     rcu_read_lock();
     policy = rcu_dereference(state->policy);
     policydb = &policy->policydb;
     sidtab = policy->sidtab;
 
     rc = -EINVAL;
     old_entry = sidtab_search_entry(sidtab, old_sid);
     if (!old_entry) {
         pr_err("SELinux: %s: unrecognized SID %u\n",
                __func__, old_sid);
         goto out;
     }
 
     rc = -EINVAL;
     new_entry = sidtab_search_entry(sidtab, new_sid);
     if (!new_entry) {
         pr_err("SELinux: %s: unrecognized SID %u\n",
                __func__, new_sid);
         goto out;
     }
 
     rc = 0;
     /* type/domain unchanged */
     if (old_entry->context.type == new_entry->context.type)
         goto out;
 
     index = new_entry->context.type;
     while (true) {
         type = policydb->type_val_to_struct[index - 1];
         BUG_ON(!type);
 
         /* not bounded anymore */
         rc = -EPERM;
         if (!type->bounds)
             break;
 
         /* @newsid is bounded by @oldsid */
         rc = 0;
         if (type->bounds == old_entry->context.type)
             break;
 
         index = type->bounds;
     }
 
     if (rc) {
         char *old_name = NULL;
         char *new_name = NULL;
         u32 length;
 
         if (!sidtab_entry_to_string(policydb, sidtab, old_entry,
                         &old_name, &length) &&
             !sidtab_entry_to_string(policydb, sidtab, new_entry,
                         &new_name, &length)) {
             audit_log(audit_context(),
                   GFP_ATOMIC, AUDIT_SELINUX_ERR,
                   "op=security_bounded_transition "
                   "seresult=denied "
                   "oldcontext=%s newcontext=%s",
                   old_name, new_name);
         }
         kfree(new_name);
         kfree(old_name);
     }
 out:
     rcu_read_unlock();
 
     return rc;
 }
 
 static void avd_init(struct selinux_policy *policy, struct av_decision *avd)
 {
     avd->allowed = 0;
     avd->auditallow = 0;
     avd->auditdeny = 0xffffffff;
     if (policy)
         avd->seqno = policy->latest_granting;
     else
         avd->seqno = 0;
     avd->flags = 0;
 }
 
 void services_compute_xperms_decision(struct extended_perms_decision *xpermd,
                     struct avtab_node *node)
 {
     unsigned int i;
 
     if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
         if (xpermd->driver != node->datum.u.xperms->driver)
             return;
     } else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
         if (!security_xperm_test(node->datum.u.xperms->perms.p,
                     xpermd->driver))
             return;
     } else {
         BUG();
     }
 
     if (node->key.specified == AVTAB_XPERMS_ALLOWED) {
         xpermd->used |= XPERMS_ALLOWED;
         if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
             memset(xpermd->allowed->p, 0xff,
                     sizeof(xpermd->allowed->p));
         }
         if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
             for (i = 0; i < ARRAY_SIZE(xpermd->allowed->p); i++)
                 xpermd->allowed->p[i] |=
                     node->datum.u.xperms->perms.p[i];
         }
     } else if (node->key.specified == AVTAB_XPERMS_AUDITALLOW) {
         xpermd->used |= XPERMS_AUDITALLOW;
         if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
             memset(xpermd->auditallow->p, 0xff,
                     sizeof(xpermd->auditallow->p));
         }
         if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
             for (i = 0; i < ARRAY_SIZE(xpermd->auditallow->p); i++)
                 xpermd->auditallow->p[i] |=
                     node->datum.u.xperms->perms.p[i];
         }
     } else if (node->key.specified == AVTAB_XPERMS_DONTAUDIT) {
         xpermd->used |= XPERMS_DONTAUDIT;
         if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
             memset(xpermd->dontaudit->p, 0xff,
                     sizeof(xpermd->dontaudit->p));
         }
         if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) {
             for (i = 0; i < ARRAY_SIZE(xpermd->dontaudit->p); i++)
                 xpermd->dontaudit->p[i] |=
                     node->datum.u.xperms->perms.p[i];
         }
     } else {
         BUG();
     }
 }
 
 void security_compute_xperms_decision(struct selinux_state *state,
                       u32 ssid,
                       u32 tsid,
                       u16 orig_tclass,
                       u8 driver,
                       struct extended_perms_decision *xpermd)
 {
     struct selinux_policy *policy;
     struct policydb *policydb;
     struct sidtab *sidtab;
     u16 tclass;
     struct context *scontext, *tcontext;
     struct avtab_key avkey;
     struct avtab_node *node;
     struct ebitmap *sattr, *tattr;
     struct ebitmap_node *snode, *tnode;
     unsigned int i, j;
 
     xpermd->driver = driver;
     xpermd->used = 0;
     memset(xpermd->allowed->p, 0, sizeof(xpermd->allowed->p));
     memset(xpermd->auditallow->p, 0, sizeof(xpermd->auditallow->p));
     memset(xpermd->dontaudit->p, 0, sizeof(xpermd->dontaudit->p));
 
     rcu_read_lock();
     if (!selinux_initialized(state))
         goto allow;
 
     policy = rcu_dereference(state->policy);
     policydb = &policy->policydb;
     sidtab = policy->sidtab;
 
     scontext = sidtab_search(sidtab, ssid);
     if (!scontext) {
         pr_err("SELinux: %s:  unrecognized SID %d\n",
                __func__, ssid);
         goto out;
     }
 
     tcontext = sidtab_search(sidtab, tsid);
     if (!tcontext) {
         pr_err("SELinux: %s:  unrecognized SID %d\n",
                __func__, tsid);
         goto out;
     }
 
     tclass = unmap_class(&policy->map, orig_tclass);
     if (unlikely(orig_tclass && !tclass)) {
         if (policydb->allow_unknown)
             goto allow;
         goto out;
     }
 
 
     if (unlikely(!tclass || tclass > policydb->p_classes.nprim)) {
         pr_warn_ratelimited("SELinux:  Invalid class %hu\n", tclass);
         goto out;
     }
 
     avkey.target_class = tclass;
     avkey.specified = AVTAB_XPERMS;
     sattr = &policydb->type_attr_map_array[scontext->type - 1];
     tattr = &policydb->type_attr_map_array[tcontext->type - 1];
     ebitmap_for_each_positive_bit(sattr, snode, i) {
         ebitmap_for_each_positive_bit(tattr, tnode, j) {
             avkey.source_type = i + 1;
             avkey.target_type = j + 1;
             for (node = avtab_search_node(&policydb->te_avtab,
                               &avkey);
                  node;
                  node = avtab_search_node_next(node, avkey.specified))
                 services_compute_xperms_decision(xpermd, node);
 
             cond_compute_xperms(&policydb->te_cond_avtab,
                         &avkey, xpermd);
         }
     }
 out:
     rcu_read_unlock();
     return;
 allow:
     memset(xpermd->allowed->p, 0xff, sizeof(xpermd->allowed->p));
     goto out;
 }
 
 /**
  * security_compute_av - Compute access vector decisions.
  * @state: SELinux state
  * @ssid: source security identifier
  * @tsid: target security identifier
  * @orig_tclass: target security class
  * @avd: access vector decisions
  * @xperms: extended permissions
  *
  * Compute a set of access vector decisions based on the
  * SID pair (@ssid, @tsid) for the permissions in @tclass.
  */
 void security_compute_av(struct selinux_state *state,
              u32 ssid,
              u32 tsid,
              u16 orig_tclass,
              struct av_decision *avd,
              struct extended_perms *xperms)
 {
     struct selinux_policy *policy;
     struct policydb *policydb;
     struct sidtab *sidtab;
     u16 tclass;
     struct context *scontext = NULL, *tcontext = NULL;
 
     rcu_read_lock();
     policy = rcu_dereference(state->policy);
     avd_init(policy, avd);
     xperms->len = 0;
     if (!selinux_initialized(state))
         goto allow;
 
     policydb = &policy->policydb;
     sidtab = policy->sidtab;
 
     scontext = sidtab_search(sidtab, ssid);
     if (!scontext) {
         pr_err("SELinux: %s:  unrecognized SID %d\n",
                __func__, ssid);
         goto out;
     }
 
     /* permissive domain? */
     if (ebitmap_get_bit(&policydb->permissive_map, scontext->type))
         avd->flags |= AVD_FLAGS_PERMISSIVE;
 
     tcontext = sidtab_search(sidtab, tsid);
     if (!tcontext) {
         pr_err("SELinux: %s:  unrecognized SID %d\n",
                __func__, tsid);
         goto out;
     }
 
     tclass = unmap_class(&policy->map, orig_tclass);
     if (unlikely(orig_tclass && !tclass)) {
         if (policydb->allow_unknown)
             goto allow;
         goto out;
     }
     context_struct_compute_av(policydb, scontext, tcontext, tclass, avd,
                   xperms);
     map_decision(&policy->map, orig_tclass, avd,
              policydb->allow_unknown);
 out:
     rcu_read_unlock();
     return;
 allow:
     avd->allowed = 0xffffffff;
     goto out;
 }
 
 void security_compute_av_user(struct selinux_state *state,
                   u32 ssid,
                   u32 tsid,
                   u16 tclass,
                   struct av_decision *avd)
 {
     struct selinux_policy *policy;
     struct policydb *policydb;
     struct sidtab *sidtab;
     struct context *scontext = NULL, *tcontext = NULL;
 
     rcu_read_lock();
     policy = rcu_dereference(state->policy);
     avd_init(policy, avd);
     if (!selinux_initialized(state))
         goto allow;
 
     policydb = &policy->policydb;
     sidtab = policy->sidtab;
 
     scontext = sidtab_search(sidtab, ssid);
     if (!scontext) {
         pr_err("SELinux: %s:  unrecognized SID %d\n",
                __func__, ssid);
         goto out;
     }
 
     /* permissive domain? */
     if (ebitmap_get_bit(&policydb->permissive_map, scontext->type))
         avd->flags |= AVD_FLAGS_PERMISSIVE;
 
     tcontext = sidtab_search(sidtab, tsid);
     if (!tcontext) {
         pr_err("SELinux: %s:  unrecognized SID %d\n",
                __func__, tsid);
         goto out;
     }
 
     if (unlikely(!tclass)) {
         if (policydb->allow_unknown)
             goto allow;
         goto out;
     }
 
     context_struct_compute_av(policydb, scontext, tcontext, tclass, avd,
                   NULL);
  out:
     rcu_read_unlock();
     return;
 allow:
     avd->allowed = 0xffffffff;
     goto out;
 }
 
 /*
  * Write the security context string representation of
  * the context structure `context' into a dynamically
  * allocated string of the correct size.  Set `*scontext'
  * to point to this string and set `*scontext_len' to
  * the length of the string.
  */
 static int context_struct_to_string(struct policydb *p,
                     struct context *context,
                     char **scontext, u32 *scontext_len)
 {
     char *scontextp;
 
     if (scontext)
         *scontext = NULL;
     *scontext_len = 0;
 
     if (context->len) {
         *scontext_len = context->len;
         if (scontext) {
             *scontext = kstrdup(context->str, GFP_ATOMIC);
             if (!(*scontext))
                 return -ENOMEM;
         }
         return 0;
     }
 
     /* Compute the size of the context. */
     *scontext_len += strlen(sym_name(p, SYM_USERS, context->user - 1)) + 1;
     *scontext_len += strlen(sym_name(p, SYM_ROLES, context->role - 1)) + 1;
     *scontext_len += strlen(sym_name(p, SYM_TYPES, context->type - 1)) + 1;
     *scontext_len += mls_compute_context_len(p, context);
 
     if (!scontext)
         return 0;
 
     /* Allocate space for the context; caller must free this space. */
     scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
     if (!scontextp)
         return -ENOMEM;
     *scontext = scontextp;
 
     /*
      * Copy the user name, role name and type name into the context.
      */
     scontextp += sprintf(scontextp, "%s:%s:%s",
         sym_name(p, SYM_USERS, context->user - 1),
         sym_name(p, SYM_ROLES, context->role - 1),
         sym_name(p, SYM_TYPES, context->type - 1));
 
     mls_sid_to_context(p, context, &scontextp);
 
     *scontextp = 0;
 
     return 0;
 }
 
 static int sidtab_entry_to_string(struct policydb *p,
                   struct sidtab *sidtab,
                   struct sidtab_entry *entry,
                   char **scontext, u32 *scontext_len)
 {
     int rc = sidtab_sid2str_get(sidtab, entry, scontext, scontext_len);
 
     if (rc != -ENOENT)
         return rc;
 
     rc = context_struct_to_string(p, &entry->context, scontext,
                       scontext_len);
     if (!rc && scontext)
         sidtab_sid2str_put(sidtab, entry, *scontext, *scontext_len);
     return rc;
 }
 
 #include "initial_sid_to_string.h"
 
 int security_sidtab_hash_stats(struct selinux_state *state, char *page)
 {
     struct selinux_policy *policy;
     int rc;
 
     if (!selinux_initialized(state)) {
         pr_err("SELinux: %s:  called before initial load_policy\n",
                __func__);
         return -EINVAL;
     }
 
     rcu_read_lock();
     policy = rcu_dereference(state->policy);
     rc = sidtab_hash_stats(policy->sidtab, page);
     rcu_read_unlock();
 
     return rc;
 }
 
 const char *security_get_initial_sid_context(u32 sid)
 {
     if (unlikely(sid > SECINITSID_NUM))
         return NULL;
     return initial_sid_to_string[sid];
 }
 
 static int security_sid_to_context_core(struct selinux_state *state,
                     u32 sid, char **scontext,
                     u32 *scontext_len, int force,
                     int only_invalid)
 {
     struct selinux_policy *policy;
     struct policydb *policydb;
     struct sidtab *sidtab;
     struct sidtab_entry *entry;
     int rc = 0;
 
     if (scontext)
         *scontext = NULL;
     *scontext_len  = 0;
 
     if (!selinux_initialized(state)) {
         if (sid <= SECINITSID_NUM) {
             char *scontextp;
             const char *s = initial_sid_to_string[sid];
 
             if (!s)
                 return -EINVAL;
             *scontext_len = strlen(s) + 1;
             if (!scontext)
                 return 0;
             scontextp = kmemdup(s, *scontext_len, GFP_ATOMIC);
             if (!scontextp)
                 return -ENOMEM;
             *scontext = scontextp;
             return 0;
         }
         pr_err("SELinux: %s:  called before initial "
                "load_policy on unknown SID %d\n", __func__, sid);
         return -EINVAL;
     }
     rcu_read_lock();
     policy = rcu_dereference(state->policy);
     policydb = &policy->policydb;
     sidtab = policy->sidtab;
 
     if (force)
         entry = sidtab_search_entry_force(sidtab, sid);
     else
         entry = sidtab_search_entry(sidtab, sid);
     if (!entry) {
         pr_err("SELinux: %s:  unrecognized SID %d\n",
             __func__, sid);
         rc = -EINVAL;
         goto out_unlock;
     }
     if (only_invalid && !entry->context.len)
         goto out_unlock;
 
     rc = sidtab_entry_to_string(policydb, sidtab, entry, scontext,
                     scontext_len);
 
 out_unlock:
     rcu_read_unlock();
     return rc;
 
 }
 
 /**
  * security_sid_to_context - Obtain a context for a given SID.
  * @state: SELinux state
  * @sid: security identifier, SID
  * @scontext: security context
  * @scontext_len: length in bytes
  *
  * Write the string representation of the context associated with @sid
  * into a dynamically allocated string of the correct size.  Set @scontext
  * to point to this string and set @scontext_len to the length of the string.
  */
 int security_sid_to_context(struct selinux_state *state,
                 u32 sid, char **scontext, u32 *scontext_len)
 {
     return security_sid_to_context_core(state, sid, scontext,
                         scontext_len, 0, 0);
 }
 
 int security_sid_to_context_force(struct selinux_state *state, u32 sid,
                   char **scontext, u32 *scontext_len)
 {
     return security_sid_to_context_core(state, sid, scontext,
                         scontext_len, 1, 0);
 }
 
 /**
  * security_sid_to_context_inval - Obtain a context for a given SID if it
  *                                 is invalid.
  * @state: SELinux state
  * @sid: security identifier, SID
  * @scontext: security context
  * @scontext_len: length in bytes
  *
  * Write the string representation of the context associated with @sid
  * into a dynamically allocated string of the correct size, but only if the
  * context is invalid in the current policy.  Set @scontext to point to
  * this string (or NULL if the context is valid) and set @scontext_len to
  * the length of the string (or 0 if the context is valid).
  */
 int security_sid_to_context_inval(struct selinux_state *state, u32 sid,
                   char **scontext, u32 *scontext_len)
 {
     return security_sid_to_context_core(state, sid, scontext,
                         scontext_len, 1, 1);
 }
 
 /*
  * Caveat:  Mutates scontext.
  */
 static int string_to_context_struct(struct policydb *pol,
                     struct sidtab *sidtabp,
                     char *scontext,
                     struct context *ctx,
                     u32 def_sid)
 {
     struct role_datum *role;
     struct type_datum *typdatum;
     struct user_datum *usrdatum;
     char *scontextp, *p, oldc;
     int rc = 0;
 
     context_init(ctx);
 
     /* Parse the security context. */
 
     rc = -EINVAL;
     scontextp = scontext;
 
     /* Extract the user. */
     p = scontextp;
     while (*p && *p != ':')
         p++;
 
     if (*p == 0)
         goto out;
 
     *p++ = 0;
 
     usrdatum = symtab_search(&pol->p_users, scontextp);
     if (!usrdatum)
         goto out;
 
     ctx->user = usrdatum->value;
 
     /* Extract role. */
     scontextp = p;
     while (*p && *p != ':')
         p++;
 
     if (*p == 0)
         goto out;
 
     *p++ = 0;
 
     role = symtab_search(&pol->p_roles, scontextp);
     if (!role)
         goto out;
     ctx->role = role->value;
 
     /* Extract type. */
     scontextp = p;
     while (*p && *p != ':')
         p++;
     oldc = *p;
     *p++ = 0;
 
     typdatum = symtab_search(&pol->p_types, scontextp);
     if (!typdatum || typdatum->attribute)
         goto out;
 
     ctx->type = typdatum->value;
 
     rc = mls_context_to_sid(pol, oldc, p, ctx, sidtabp, def_sid);
     if (rc)
         goto out;
 
     /* Check the validity of the new context. */
     rc = -EINVAL;
     if (!policydb_context_isvalid(pol, ctx))
         goto out;
     rc = 0;
 out:
     if (rc)
         context_destroy(ctx);
     return rc;
 }
 
 static int security_context_to_sid_core(struct selinux_state *state,
                     const char *scontext, u32 scontext_len,
                     u32 *sid, u32 def_sid, gfp_t gfp_flags,
                     int force)
 {
     struct selinux_policy *policy;
     struct policydb *policydb;
     struct sidtab *sidtab;
     char *scontext2, *str = NULL;
     struct context context;
     int rc = 0;
 
     /* An empty security context is never valid. */
     if (!scontext_len)
         return -EINVAL;
 
     /* Copy the string to allow changes and ensure a NUL terminator */
     scontext2 = kmemdup_nul(scontext, scontext_len, gfp_flags);
     if (!scontext2)
         return -ENOMEM;
 
     if (!selinux_initialized(state)) {
         int i;
 
         for (i = 1; i < SECINITSID_NUM; i++) {
             const char *s = initial_sid_to_string[i];
 
             if (s && !strcmp(s, scontext2)) {
                 *sid = i;
                 goto out;
             }
         }
         *sid = SECINITSID_KERNEL;
         goto out;
     }
     *sid = SECSID_NULL;
 
     if (force) {
         /* Save another copy for storing in uninterpreted form */
         rc = -ENOMEM;
         str = kstrdup(scontext2, gfp_flags);
         if (!str)
             goto out;
     }
 retry:
     rcu_read_lock();
     policy = rcu_dereference(state->policy);
     policydb = &policy->policydb;
     sidtab = policy->sidtab;
     rc = string_to_context_struct(policydb, sidtab, scontext2,
                       &context, def_sid);
     if (rc == -EINVAL && force) {
         context.str = str;
         context.len = strlen(str) + 1;
         str = NULL;
     } else if (rc)
         goto out_unlock;
     rc = sidtab_context_to_sid(sidtab, &context, sid);
     if (rc == -ESTALE) {
         rcu_read_unlock();
         if (context.str) {
             str = context.str;
             context.str = NULL;
         }
         context_destroy(&context);
         goto retry;
     }
     context_destroy(&context);
 out_unlock:
     rcu_read_unlock();
 out:
     kfree(scontext2);
     kfree(str);
     return rc;
 }
 
 /**
  * security_context_to_sid - Obtain a SID for a given security context.
  * @state: SELinux state
  * @scontext: security context
  * @scontext_len: length in bytes
  * @sid: security identifier, SID
  * @gfp: context for the allocation
  *
  * Obtains a SID associated with the security context that
  * has the string representation specified by @scontext.
  * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
  * memory is available, or 0 on success.
  */
 int security_context_to_sid(struct selinux_state *state,
                 const char *scontext, u32 scontext_len, u32 *sid,
                 gfp_t gfp)
 {
     return security_context_to_sid_core(state, scontext, scontext_len,
                         sid, SECSID_NULL, gfp, 0);
 }
 
 int security_context_str_to_sid(struct selinux_state *state,
                 const char *scontext, u32 *sid, gfp_t gfp)
 {
     return security_context_to_sid(state, scontext, strlen(scontext),
                        sid, gfp);
 }
 
 /**
  * security_context_to_sid_default - Obtain a SID for a given security context,
  * falling back to specified default if needed.
  *
  * @state: SELinux state
  * @scontext: security context
  * @scontext_len: length in bytes
  * @sid: security identifier, SID
  * @def_sid: default SID to assign on error
  * @gfp_flags: the allocator get-free-page (GFP) flags
  *
  * Obtains a SID associated with the security context that
  * has the string representation specified by @scontext.
  * The default SID is passed to the MLS layer to be used to allow
  * kernel labeling of the MLS field if the MLS field is not present
  * (for upgrading to MLS without full relabel).
  * Implicitly forces adding of the context even if it cannot be mapped yet.
  * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
  * memory is available, or 0 on success.
  */
 int security_context_to_sid_default(struct selinux_state *state,
                     const char *scontext, u32 scontext_len,
                     u32 *sid, u32 def_sid, gfp_t gfp_flags)
 {
     return security_context_to_sid_core(state, scontext, scontext_len,
                         sid, def_sid, gfp_flags, 1);
 }
 
 int security_context_to_sid_force(struct selinux_state *state,
                   const char *scontext, u32 scontext_len,
                   u32 *sid)
 {
     return security_context_to_sid_core(state, scontext, scontext_len,
                         sid, SECSID_NULL, GFP_KERNEL, 1);
 }
 
 static int compute_sid_handle_invalid_context(
     struct selinux_state *state,
     struct selinux_policy *policy,
     struct sidtab_entry *sentry,
     struct sidtab_entry *tentry,
     u16 tclass,
     struct context *newcontext)
 {
     struct policydb *policydb = &policy->policydb;
     struct sidtab *sidtab = policy->sidtab;
     char *s = NULL, *t = NULL, *n = NULL;
     u32 slen, tlen, nlen;
     struct audit_buffer *ab;
 
     if (sidtab_entry_to_string(policydb, sidtab, sentry, &s, &slen))
         goto out;
     if (sidtab_entry_to_string(policydb, sidtab, tentry, &t, &tlen))
         goto out;
     if (context_struct_to_string(policydb, newcontext, &n, &nlen))
         goto out;
     ab = audit_log_start(audit_context(), GFP_ATOMIC, AUDIT_SELINUX_ERR);
     if (!ab)
         goto out;
     audit_log_format(ab,
              "op=security_compute_sid invalid_context=");
     /* no need to record the NUL with untrusted strings */
     audit_log_n_untrustedstring(ab, n, nlen - 1);
     audit_log_format(ab, " scontext=%s tcontext=%s tclass=%s",
              s, t, sym_name(policydb, SYM_CLASSES, tclass-1));
     audit_log_end(ab);
 out:
     kfree(s);
     kfree(t);
     kfree(n);
     if (!enforcing_enabled(state))
         return 0;
     return -EACCES;
 }
 
 static void filename_compute_type(struct policydb *policydb,
                   struct context *newcontext,
                   u32 stype, u32 ttype, u16 tclass,
                   const char *objname)
 {
     struct filename_trans_key ft;
     struct filename_trans_datum *datum;
 
     /*
      * Most filename trans rules are going to live in specific directories
      * like /dev or /var/run.  This bitmap will quickly skip rule searches
      * if the ttype does not contain any rules.
      */
     if (!ebitmap_get_bit(&policydb->filename_trans_ttypes, ttype))
         return;
 
     ft.ttype = ttype;
     ft.tclass = tclass;
     ft.name = objname;
 
     datum = policydb_filenametr_search(policydb, &ft);
     while (datum) {
         if (ebitmap_get_bit(&datum->stypes, stype - 1)) {
             newcontext->type = datum->otype;
             return;
         }
         datum = datum->next;
     }
 }
 
 static int security_compute_sid(struct selinux_state *state,
                 u32 ssid,
                 u32 tsid,
                 u16 orig_tclass,
                 u32 specified,
                 const char *objname,
                 u32 *out_sid,
                 bool kern)
 {
     struct selinux_policy *policy;
     struct policydb *policydb;
     struct sidtab *sidtab;
     struct class_datum *cladatum;
     struct context *scontext, *tcontext, newcontext;
     struct sidtab_entry *sentry, *tentry;
     struct avtab_key avkey;
     struct avtab_datum *avdatum;
     struct avtab_node *node;
     u16 tclass;
     int rc = 0;
     bool sock;
 
     if (!selinux_initialized(state)) {
         switch (orig_tclass) {
         case SECCLASS_PROCESS: /* kernel value */
             *out_sid = ssid;
             break;
         default:
             *out_sid = tsid;
             break;
         }
         goto out;
     }
 
 retry:
     cladatum = NULL;
     context_init(&newcontext);
 
     rcu_read_lock();
 
     policy = rcu_dereference(state->policy);
 
     if (kern) {
         tclass = unmap_class(&policy->map, orig_tclass);
         sock = security_is_socket_class(orig_tclass);
     } else {
         tclass = orig_tclass;
         sock = security_is_socket_class(map_class(&policy->map,
                               tclass));
     }
 
     policydb = &policy->policydb;
     sidtab = policy->sidtab;
 
     sentry = sidtab_search_entry(sidtab, ssid);
     if (!sentry) {
         pr_err("SELinux: %s:  unrecognized SID %d\n",
                __func__, ssid);
         rc = -EINVAL;
         goto out_unlock;
     }
     tentry = sidtab_search_entry(sidtab, tsid);
     if (!tentry) {
         pr_err("SELinux: %s:  unrecognized SID %d\n",
                __func__, tsid);
         rc = -EINVAL;
         goto out_unlock;
     }
 
     scontext = &sentry->context;
     tcontext = &tentry->context;
 
     if (tclass && tclass <= policydb->p_classes.nprim)
         cladatum = policydb->class_val_to_struct[tclass - 1];
 
     /* Set the user identity. */
     switch (specified) {
     case AVTAB_TRANSITION:
     case AVTAB_CHANGE:
         if (cladatum && cladatum->default_user == DEFAULT_TARGET) {
             newcontext.user = tcontext->user;
         } else {
             /* notice this gets both DEFAULT_SOURCE and unset */
             /* Use the process user identity. */
             newcontext.user = scontext->user;
         }
         break;
     case AVTAB_MEMBER:
         /* Use the related object owner. */
         newcontext.user = tcontext->user;
         break;
     }
 
     /* Set the role to default values. */
     if (cladatum && cladatum->default_role == DEFAULT_SOURCE) {
         newcontext.role = scontext->role;
     } else if (cladatum && cladatum->default_role == DEFAULT_TARGET) {
         newcontext.role = tcontext->role;
     } else {
         if ((tclass == policydb->process_class) || sock)
             newcontext.role = scontext->role;
         else
             newcontext.role = OBJECT_R_VAL;
     }
 
     /* Set the type to default values. */
     if (cladatum && cladatum->default_type == DEFAULT_SOURCE) {
         newcontext.type = scontext->type;
     } else if (cladatum && cladatum->default_type == DEFAULT_TARGET) {
         newcontext.type = tcontext->type;
     } else {
         if ((tclass == policydb->process_class) || sock) {
             /* Use the type of process. */
             newcontext.type = scontext->type;
         } else {
             /* Use the type of the related object. */
             newcontext.type = tcontext->type;
         }
     }
 
     /* Look for a type transition/member/change rule. */
     avkey.source_type = scontext->type;
     avkey.target_type = tcontext->type;
     avkey.target_class = tclass;
     avkey.specified = specified;
     avdatum = avtab_search(&policydb->te_avtab, &avkey);
 
     /* If no permanent rule, also check for enabled conditional rules */
     if (!avdatum) {
         node = avtab_search_node(&policydb->te_cond_avtab, &avkey);
         for (; node; node = avtab_search_node_next(node, specified)) {
             if (node->key.specified & AVTAB_ENABLED) {
                 avdatum = &node->datum;
                 break;
             }
         }
     }
 
     if (avdatum) {
         /* Use the type from the type transition/member/change rule. */
         newcontext.type = avdatum->u.data;
     }
 
     /* if we have a objname this is a file trans check so check those rules */
     if (objname)
         filename_compute_type(policydb, &newcontext, scontext->type,
                       tcontext->type, tclass, objname);
 
     /* Check for class-specific changes. */
     if (specified & AVTAB_TRANSITION) {
         /* Look for a role transition rule. */
         struct role_trans_datum *rtd;
         struct role_trans_key rtk = {
             .role = scontext->role,
             .type = tcontext->type,
             .tclass = tclass,
         };
 
         rtd = policydb_roletr_search(policydb, &rtk);
         if (rtd)
             newcontext.role = rtd->new_role;
     }
 
     /* Set the MLS attributes.
        This is done last because it may allocate memory. */
     rc = mls_compute_sid(policydb, scontext, tcontext, tclass, specified,
                  &newcontext, sock);
     if (rc)
         goto out_unlock;
 
     /* Check the validity of the context. */
     if (!policydb_context_isvalid(policydb, &newcontext)) {
         rc = compute_sid_handle_invalid_context(state, policy, sentry,
                             tentry, tclass,
                             &newcontext);
         if (rc)
             goto out_unlock;
     }
     /* Obtain the sid for the context. */
     rc = sidtab_context_to_sid(sidtab, &newcontext, out_sid);
     if (rc == -ESTALE) {
         rcu_read_unlock();
         context_destroy(&newcontext);
         goto retry;
     }
 out_unlock:
     rcu_read_unlock();
     context_destroy(&newcontext);
 out:
     return rc;
 }
 
 /**
  * security_transition_sid - Compute the SID for a new subject/object.
  * @state: SELinux state
  * @ssid: source security identifier
  * @tsid: target security identifier
  * @tclass: target security class
  * @qstr: object name
  * @out_sid: security identifier for new subject/object
  *
  * Compute a SID to use for labeling a new subject or object in the
  * class @tclass based on a SID pair (@ssid, @tsid).
  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
  * if insufficient memory is available, or %0 if the new SID was
  * computed successfully.
  */
 int security_transition_sid(struct selinux_state *state,
                 u32 ssid, u32 tsid, u16 tclass,
                 const struct qstr *qstr, u32 *out_sid)
 {
     return security_compute_sid(state, ssid, tsid, tclass,
                     AVTAB_TRANSITION,
                     qstr ? qstr->name : NULL, out_sid, true);
 }
 
 int security_transition_sid_user(struct selinux_state *state,
                  u32 ssid, u32 tsid, u16 tclass,
                  const char *objname, u32 *out_sid)
 {
     return security_compute_sid(state, ssid, tsid, tclass,
                     AVTAB_TRANSITION,
                     objname, out_sid, false);
 }
 
 /**
  * security_member_sid - Compute the SID for member selection.
  * @state: SELinux state
  * @ssid: source security identifier
  * @tsid: target security identifier
  * @tclass: target security class
  * @out_sid: security identifier for selected member
  *
  * Compute a SID to use when selecting a member of a polyinstantiated
  * object of class @tclass based on a SID pair (@ssid, @tsid).
  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
  * if insufficient memory is available, or %0 if the SID was
  * computed successfully.
  */
 int security_member_sid(struct selinux_state *state,
             u32 ssid,
             u32 tsid,
             u16 tclass,
             u32 *out_sid)
 {
     return security_compute_sid(state, ssid, tsid, tclass,
                     AVTAB_MEMBER, NULL,
                     out_sid, false);
 }
 
 /**
  * security_change_sid - Compute the SID for object relabeling.
  * @state: SELinux state
  * @ssid: source security identifier
  * @tsid: target security identifier
  * @tclass: target security class
  * @out_sid: security identifier for selected member
  *
  * Compute a SID to use for relabeling an object of class @tclass
  * based on a SID pair (@ssid, @tsid).
  * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
  * if insufficient memory is available, or %0 if the SID was
  * computed successfully.
  */
 int security_change_sid(struct selinux_state *state,
             u32 ssid,
             u32 tsid,
             u16 tclass,
             u32 *out_sid)
 {
     return security_compute_sid(state,
                     ssid, tsid, tclass, AVTAB_CHANGE, NULL,
                     out_sid, false);
 }
 
 static inline int convert_context_handle_invalid_context(
     struct selinux_state *state,
     struct policydb *policydb,
     struct context *context)
 {
     char *s;
     u32 len;
 
     if (enforcing_enabled(state))
         return -EINVAL;
 
     if (!context_struct_to_string(policydb, context, &s, &len)) {
         pr_warn("SELinux:  Context %s would be invalid if enforcing\n",
             s);
         kfree(s);
     }
     return 0;
 }
 
 /*
  * Convert the values in the security context
  * structure `oldc' from the values specified
  * in the policy `p->oldp' to the values specified
  * in the policy `p->newp', storing the new context
  * in `newc'.  Verify that the context is valid
  * under the new policy.
  */
 static int convert_context(struct context *oldc, struct context *newc, void *p)
 {
     struct convert_context_args *args;
     struct ocontext *oc;
     struct role_datum *role;
     struct type_datum *typdatum;
     struct user_datum *usrdatum;
     char *s;
     u32 len;
     int rc;
 
     args = p;
 
     if (oldc->str) {
         s = kstrdup(oldc->str, GFP_KERNEL);
         if (!s)
             return -ENOMEM;
 
         rc = string_to_context_struct(args->newp, NULL, s,
                           newc, SECSID_NULL);
         if (rc == -EINVAL) {
             /*
              * Retain string representation for later mapping.
              *
              * IMPORTANT: We need to copy the contents of oldc->str
              * back into s again because string_to_context_struct()
              * may have garbled it.
              */
             memcpy(s, oldc->str, oldc->len);
             context_init(newc);
             newc->str = s;
             newc->len = oldc->len;
             return 0;
         }
         kfree(s);
         if (rc) {
             /* Other error condition, e.g. ENOMEM. */
             pr_err("SELinux:   Unable to map context %s, rc = %d.\n",
                    oldc->str, -rc);
             return rc;
         }
         pr_info("SELinux:  Context %s became valid (mapped).\n",
             oldc->str);
         return 0;
     }
 
     context_init(newc);
 
     /* Convert the user. */
     usrdatum = symtab_search(&args->newp->p_users,
                  sym_name(args->oldp,
                       SYM_USERS, oldc->user - 1));
     if (!usrdatum)
         goto bad;
     newc->user = usrdatum->value;
 
     /* Convert the role. */
     role = symtab_search(&args->newp->p_roles,
                  sym_name(args->oldp, SYM_ROLES, oldc->role - 1));
     if (!role)
         goto bad;
     newc->role = role->value;
 
     /* Convert the type. */
     typdatum = symtab_search(&args->newp->p_types,
                  sym_name(args->oldp,
                       SYM_TYPES, oldc->type - 1));
     if (!typdatum)
         goto bad;
     newc->type = typdatum->value;
 
     /* Convert the MLS fields if dealing with MLS policies */
     if (args->oldp->mls_enabled && args->newp->mls_enabled) {
         rc = mls_convert_context(args->oldp, args->newp, oldc, newc);
         if (rc)
             goto bad;
     } else if (!args->oldp->mls_enabled && args->newp->mls_enabled) {
         /*
          * Switching between non-MLS and MLS policy:
          * ensure that the MLS fields of the context for all
          * existing entries in the sidtab are filled in with a
          * suitable default value, likely taken from one of the
          * initial SIDs.
          */
         oc = args->newp->ocontexts[OCON_ISID];
         while (oc && oc->sid[0] != SECINITSID_UNLABELED)
             oc = oc->next;
         if (!oc) {
             pr_err("SELinux:  unable to look up"
                 " the initial SIDs list\n");
             goto bad;
         }
         rc = mls_range_set(newc, &oc->context[0].range);
         if (rc)
             goto bad;
     }
 
     /* Check the validity of the new context. */
     if (!policydb_context_isvalid(args->newp, newc)) {
         rc = convert_context_handle_invalid_context(args->state,
                             args->oldp,
                             oldc);
         if (rc)
             goto bad;
     }
 
     return 0;
 bad:
     /* Map old representation to string and save it. */
     rc = context_struct_to_string(args->oldp, oldc, &s, &len);
     if (rc)
         return rc;
     context_destroy(newc);
     newc->str = s;
     newc->len = len;
     pr_info("SELinux:  Context %s became invalid (unmapped).\n",
         newc->str);
     return 0;
 }
 
 static void security_load_policycaps(struct selinux_state *state,
                 struct selinux_policy *policy)
 {
     struct policydb *p;
     unsigned int i;
     struct ebitmap_node *node;
 
     p = &policy->policydb;
 
     for (i = 0; i < ARRAY_SIZE(state->policycap); i++)
         WRITE_ONCE(state->policycap[i],
             ebitmap_get_bit(&p->policycaps, i));
 
     for (i = 0; i < ARRAY_SIZE(selinux_policycap_names); i++)
         pr_info("SELinux:  policy capability %s=%d\n",
             selinux_policycap_names[i],
             ebitmap_get_bit(&p->policycaps, i));
 
     ebitmap_for_each_positive_bit(&p->policycaps, node, i) {
         if (i >= ARRAY_SIZE(selinux_policycap_names))
             pr_info("SELinux:  unknown policy capability %u\n",
                 i);
     }
 }
 
 static int security_preserve_bools(struct selinux_policy *oldpolicy,
                 struct selinux_policy *newpolicy);
 
 static void selinux_policy_free(struct selinux_policy *policy)
 {
     if (!policy)
         return;
 
     sidtab_destroy(policy->sidtab);
     kfree(policy->map.mapping);
     policydb_destroy(&policy->policydb);
     kfree(policy->sidtab);
     kfree(policy);
 }
 
 static void selinux_policy_cond_free(struct selinux_policy *policy)
 {
     cond_policydb_destroy_dup(&policy->policydb);
     kfree(policy);
 }
 
 void selinux_policy_cancel(struct selinux_state *state,
                struct selinux_load_state *load_state)
 {
     struct selinux_policy *oldpolicy;
 
     oldpolicy = rcu_dereference_protected(state->policy,
                     lockdep_is_held(&state->policy_mutex));
 
     sidtab_cancel_convert(oldpolicy->sidtab);
     selinux_policy_free(load_state->policy);
     kfree(load_state->convert_data);
 }
 
 static void selinux_notify_policy_change(struct selinux_state *state,
                     u32 seqno)
 {
     /* Flush external caches and notify userspace of policy load */
     avc_ss_reset(state->avc, seqno);
     selnl_notify_policyload(seqno);
     selinux_status_update_policyload(state, seqno);
     selinux_netlbl_cache_invalidate();
     selinux_xfrm_notify_policyload();
     selinux_ima_measure_state_locked(state);
 }
 
 void selinux_policy_commit(struct selinux_state *state,
                struct selinux_load_state *load_state)
 {
     struct selinux_policy *oldpolicy, *newpolicy = load_state->policy;
     unsigned long flags;
     u32 seqno;
 
     oldpolicy = rcu_dereference_protected(state->policy,
                     lockdep_is_held(&state->policy_mutex));
 
     /* If switching between different policy types, log MLS status */
     if (oldpolicy) {
         if (oldpolicy->policydb.mls_enabled && !newpolicy->policydb.mls_enabled)
             pr_info("SELinux: Disabling MLS support...\n");
         else if (!oldpolicy->policydb.mls_enabled && newpolicy->policydb.mls_enabled)
             pr_info("SELinux: Enabling MLS support...\n");
     }
 
     /* Set latest granting seqno for new policy. */
     if (oldpolicy)
         newpolicy->latest_granting = oldpolicy->latest_granting + 1;
     else
         newpolicy->latest_granting = 1;
     seqno = newpolicy->latest_granting;
 
     /* Install the new policy. */
     if (oldpolicy) {
         sidtab_freeze_begin(oldpolicy->sidtab, &flags);
         rcu_assign_pointer(state->policy, newpolicy);
         sidtab_freeze_end(oldpolicy->sidtab, &flags);
     } else {
         rcu_assign_pointer(state->policy, newpolicy);
     }
 
     /* Load the policycaps from the new policy */
     security_load_policycaps(state, newpolicy);
 
     if (!selinux_initialized(state)) {
         /*
          * After first policy load, the security server is
          * marked as initialized and ready to handle requests and
          * any objects created prior to policy load are then labeled.
          */
         selinux_mark_initialized(state);
         selinux_complete_init();
     }
 
     /* Free the old policy */
     synchronize_rcu();
     selinux_policy_free(oldpolicy);
     kfree(load_state->convert_data);
 
     /* Notify others of the policy change */
     selinux_notify_policy_change(state, seqno);
 }
 
 /**
  * security_load_policy - Load a security policy configuration.
  * @state: SELinux state
  * @data: binary policy data
  * @len: length of data in bytes
  * @load_state: policy load state
  *
  * Load a new set of security policy configuration data,
  * validate it and convert the SID table as necessary.
  * This function will flush the access vector cache after
  * loading the new policy.
  */
 int security_load_policy(struct selinux_state *state, void *data, size_t len,
              struct selinux_load_state *load_state)
 {
     struct selinux_policy *newpolicy, *oldpolicy;
     struct selinux_policy_convert_data *convert_data;
     int rc = 0;
     struct policy_file file = { data, len }, *fp = &file;
 
     newpolicy = kzalloc(sizeof(*newpolicy), GFP_KERNEL);
     if (!newpolicy)
         return -ENOMEM;
 
     newpolicy->sidtab = kzalloc(sizeof(*newpolicy->sidtab), GFP_KERNEL);
     if (!newpolicy->sidtab) {
         rc = -ENOMEM;
         goto err_policy;
     }
 
     rc = policydb_read(&newpolicy->policydb, fp);
     if (rc)
         goto err_sidtab;
 
     newpolicy->policydb.len = len;
     rc = selinux_set_mapping(&newpolicy->policydb, secclass_map,
                 &newpolicy->map);
     if (rc)
         goto err_policydb;
 
     rc = policydb_load_isids(&newpolicy->policydb, newpolicy->sidtab);
     if (rc) {
         pr_err("SELinux:  unable to load the initial SIDs\n");
         goto err_mapping;
     }
 
     if (!selinux_initialized(state)) {
         /* First policy load, so no need to preserve state from old policy */
         load_state->policy = newpolicy;
         load_state->convert_data = NULL;
         return 0;
     }
 
     oldpolicy = rcu_dereference_protected(state->policy,
                     lockdep_is_held(&state->policy_mutex));
 
     /* Preserve active boolean values from the old policy */
     rc = security_preserve_bools(oldpolicy, newpolicy);
     if (rc) {
         pr_err("SELinux:  unable to preserve booleans\n");
         goto err_free_isids;
     }
 
     convert_data = kmalloc(sizeof(*convert_data), GFP_KERNEL);
     if (!convert_data) {
         rc = -ENOMEM;
         goto err_free_isids;
     }
 
     /*
      * Convert the internal representations of contexts
      * in the new SID table.
      */
     convert_data->args.state = state;
     convert_data->args.oldp = &oldpolicy->policydb;
     convert_data->args.newp = &newpolicy->policydb;
 
     convert_data->sidtab_params.func = convert_context;
     convert_data->sidtab_params.args = &convert_data->args;
     convert_data->sidtab_params.target = newpolicy->sidtab;
 
     rc = sidtab_convert(oldpolicy->sidtab, &convert_data->sidtab_params);
     if (rc) {
         pr_err("SELinux:  unable to convert the internal"
             " representation of contexts in the new SID"
             " table\n");
         goto err_free_convert_data;
     }
 
     load_state->policy = newpolicy;
     load_state->convert_data = convert_data;
     return 0;
 
 err_free_convert_data:
     kfree(convert_data);
 err_free_isids:
     sidtab_destroy(newpolicy->sidtab);
 err_mapping:
     kfree(newpolicy->map.mapping);
 err_policydb:
     policydb_destroy(&newpolicy->policydb);
 err_sidtab:
     kfree(newpolicy->sidtab);
 err_policy:
     kfree(newpolicy);
 
     return rc;
 }
 
 /**
  * ocontext_to_sid - Helper to safely get sid for an ocontext
  * @sidtab: SID table
  * @c: ocontext structure
  * @index: index of the context entry (0 or 1)
  * @out_sid: pointer to the resulting SID value
  *
  * For all ocontexts except OCON_ISID the SID fields are populated
  * on-demand when needed. Since updating the SID value is an SMP-sensitive
  * operation, this helper must be used to do that safely.
  *
  * WARNING: This function may return -ESTALE, indicating that the caller
  * must retry the operation after re-acquiring the policy pointer!
  */
 static int ocontext_to_sid(struct sidtab *sidtab, struct ocontext *c,
                size_t index, u32 *out_sid)
 {
     int rc;
     u32 sid;
 
     /* Ensure the associated sidtab entry is visible to this thread. */
     sid = smp_load_acquire(&c->sid[index]);
     if (!sid) {
         rc = sidtab_context_to_sid(sidtab, &c->context[index], &sid);
         if (rc)
             return rc;
 
         /*
          * Ensure the new sidtab entry is visible to other threads
          * when they see the SID.
          */
         smp_store_release(&c->sid[index], sid);
     }
     *out_sid = sid;
     return 0;
 }
 
 /**
  * security_port_sid - Obtain the SID for a port.
  * @state: SELinux state
  * @protocol: protocol number
  * @port: port number
  * @out_sid: security identifier
  */
 int security_port_sid(struct selinux_state *state,
               u8 protocol, u16 port, u32 *out_sid)
 {
     struct selinux_policy *policy;
     struct policydb *policydb;
     struct sidtab *sidtab;
     struct ocontext *c;
     int rc;
 
     if (!selinux_initialized(state)) {
         *out_sid = SECINITSID_PORT;
         return 0;
     }
 
 retry:
     rc = 0;
     rcu_read_lock();
     policy = rcu_dereference(state->policy);
     policydb = &policy->policydb;
     sidtab = policy->sidtab;
 
     c = policydb->ocontexts[OCON_PORT];
     while (c) {
         if (c->u.port.protocol == protocol &&
             c->u.port.low_port <= port &&
             c->u.port.high_port >= port)
             break;
         c = c->next;
     }
 
     if (c) {
         rc = ocontext_to_sid(sidtab, c, 0, out_sid);
         if (rc == -ESTALE) {
             rcu_read_unlock();
             goto retry;
         }
         if (rc)
             goto out;
     } else {
         *out_sid = SECINITSID_PORT;
     }
 
 out:
     rcu_read_unlock();
     return rc;
 }
 
 /**
  * security_ib_pkey_sid - Obtain the SID for a pkey.
  * @state: SELinux state
  * @subnet_prefix: Subnet Prefix
  * @pkey_num: pkey number
  * @out_sid: security identifier
  */
 int security_ib_pkey_sid(struct selinux_state *state,
              u64 subnet_prefix, u16 pkey_num, u32 *out_sid)
 {
     struct selinux_policy *policy;
     struct policydb *policydb;
     struct sidtab *sidtab;
     struct ocontext *c;
     int rc;
 
     if (!selinux_initialized(state)) {
         *out_sid = SECINITSID_UNLABELED;
         return 0;
     }
 
 retry:
     rc = 0;
     rcu_read_lock();
     policy = rcu_dereference(state->policy);
     policydb = &policy->policydb;
     sidtab = policy->sidtab;
 
     c = policydb->ocontexts[OCON_IBPKEY];
     while (c) {
         if (c->u.ibpkey.low_pkey <= pkey_num &&
             c->u.ibpkey.high_pkey >= pkey_num &&
             c->u.ibpkey.subnet_prefix == subnet_prefix)
             break;
 
         c = c->next;
     }
 
     if (c) {
         rc = ocontext_to_sid(sidtab, c, 0, out_sid);
         if (rc == -ESTALE) {
             rcu_read_unlock();
             goto retry;
         }
         if (rc)
             goto out;
     } else
         *out_sid = SECINITSID_UNLABELED;
 
 out:
     rcu_read_unlock();
     return rc;
 }
 
 /**
  * security_ib_endport_sid - Obtain the SID for a subnet management interface.
  * @state: SELinux state
  * @dev_name: device name
  * @port_num: port number
  * @out_sid: security identifier
  */
 int security_ib_endport_sid(struct selinux_state *state,
                 const char *dev_name, u8 port_num, u32 *out_sid)
 {
     struct selinux_policy *policy;
     struct policydb *policydb;
     struct sidtab *sidtab;
     struct ocontext *c;
     int rc;
 
     if (!selinux_initialized(state)) {
         *out_sid = SECINITSID_UNLABELED;
         return 0;
     }
 
 retry:
     rc = 0;
     rcu_read_lock();
     policy = rcu_dereference(state->policy);
     policydb = &policy->policydb;
     sidtab = policy->sidtab;
 
     c = policydb->ocontexts[OCON_IBENDPORT];
     while (c) {
         if (c->u.ibendport.port == port_num &&
             !strncmp(c->u.ibendport.dev_name,
                  dev_name,
                  IB_DEVICE_NAME_MAX))
             break;
 
         c = c->next;
     }
 
     if (c) {
         rc = ocontext_to_sid(sidtab, c, 0, out_sid);
         if (rc == -ESTALE) {
             rcu_read_unlock();
             goto retry;
         }
         if (rc)
             goto out;
     } else
         *out_sid = SECINITSID_UNLABELED;
 
 out:
     rcu_read_unlock();
     return rc;
 }
 
 /**
  * security_netif_sid - Obtain the SID for a network interface.
  * @state: SELinux state
  * @name: interface name
  * @if_sid: interface SID
  */
 int security_netif_sid(struct selinux_state *state,
                char *name, u32 *if_sid)
 {
     struct selinux_policy *policy;
     struct policydb *policydb;
     struct sidtab *sidtab;
     int rc;
     struct ocontext *c;
 
     if (!selinux_initialized(state)) {
         *if_sid = SECINITSID_NETIF;
         return 0;
     }
 
 retry:
     rc = 0;
     rcu_read_lock();
     policy = rcu_dereference(state->policy);
     policydb = &policy->policydb;
     sidtab = policy->sidtab;
 
     c = policydb->ocontexts[OCON_NETIF];
     while (c) {
         if (strcmp(name, c->u.name) == 0)
             break;
         c = c->next;
     }
 
     if (c) {
         rc = ocontext_to_sid(sidtab, c, 0, if_sid);
         if (rc == -ESTALE) {
             rcu_read_unlock();
             goto retry;
         }
         if (rc)
             goto out;
     } else
         *if_sid = SECINITSID_NETIF;
 
 out:
     rcu_read_unlock();
     return rc;
 }
 
 static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask)
 {
     int i, fail = 0;
 
     for (i = 0; i < 4; i++)
         if (addr[i] != (input[i] & mask[i])) {
             fail = 1;
             break;
         }
 
     return !fail;
 }
 
 /**
  * security_node_sid - Obtain the SID for a node (host).
  * @state: SELinux state
  * @domain: communication domain aka address family
  * @addrp: address
  * @addrlen: address length in bytes
  * @out_sid: security identifier
  */
 int security_node_sid(struct selinux_state *state,
               u16 domain,
               void *addrp,
               u32 addrlen,
               u32 *out_sid)
 {
     struct selinux_policy *policy;
     struct policydb *policydb;
     struct sidtab *sidtab;
     int rc;
     struct ocontext *c;
 
     if (!selinux_initialized(state)) {
         *out_sid = SECINITSID_NODE;
         return 0;
     }
 
 retry:
     rcu_read_lock();
     policy = rcu_dereference(state->policy);
     policydb = &policy->policydb;
     sidtab = policy->sidtab;
 
     switch (domain) {
     case AF_INET: {
         u32 addr;
 
         rc = -EINVAL;
         if (addrlen != sizeof(u32))
             goto out;
 
         addr = *((u32 *)addrp);
 
         c = policydb->ocontexts[OCON_NODE];
         while (c) {
             if (c->u.node.addr == (addr & c->u.node.mask))
                 break;
             c = c->next;
         }
         break;
     }
 
     case AF_INET6:
         rc = -EINVAL;
         if (addrlen != sizeof(u64) * 2)
             goto out;
         c = policydb->ocontexts[OCON_NODE6];
         while (c) {
             if (match_ipv6_addrmask(addrp, c->u.node6.addr,
                         c->u.node6.mask))
                 break;
             c = c->next;
         }
         break;
 
     default:
         rc = 0;
         *out_sid = SECINITSID_NODE;
         goto out;
     }
 
     if (c) {
         rc = ocontext_to_sid(sidtab, c, 0, out_sid);
         if (rc == -ESTALE) {
             rcu_read_unlock();
             goto retry;
         }
         if (rc)
             goto out;
     } else {
         *out_sid = SECINITSID_NODE;
     }
 
     rc = 0;
 out:
     rcu_read_unlock();
     return rc;
 }
 
 #define SIDS_NEL 25
 
 /**
  * security_get_user_sids - Obtain reachable SIDs for a user.
  * @state: SELinux state
  * @fromsid: starting SID
  * @username: username
  * @sids: array of reachable SIDs for user
  * @nel: number of elements in @sids
  *
  * Generate the set of SIDs for legal security contexts
  * for a given user that can be reached by @fromsid.
  * Set *@sids to point to a dynamically allocated
  * array containing the set of SIDs.  Set *@nel to the
  * number of elements in the array.
  */
 
 int security_get_user_sids(struct selinux_state *state,
                u32 fromsid,
                char *username,
                u32 **sids,
                u32 *nel)
 {
     struct selinux_policy *policy;
     struct policydb *policydb;
     struct sidtab *sidtab;
     struct context *fromcon, usercon;
     u32 *mysids = NULL, *mysids2, sid;
     u32 i, j, mynel, maxnel = SIDS_NEL;
     struct user_datum *user;
     struct role_datum *role;
     struct ebitmap_node *rnode, *tnode;
     int rc;
 
     *sids = NULL;
     *nel = 0;
 
     if (!selinux_initialized(state))
         return 0;
 
     mysids = kcalloc(maxnel, sizeof(*mysids), GFP_KERNEL);
     if (!mysids)
         return -ENOMEM;
 
 retry:
     mynel = 0;
     rcu_read_lock();
     policy = rcu_dereference(state->policy);
     policydb = &policy->policydb;
     sidtab = policy->sidtab;
 
     context_init(&usercon);
 
     rc = -EINVAL;
     fromcon = sidtab_search(sidtab, fromsid);
     if (!fromcon)
         goto out_unlock;
 
     rc = -EINVAL;
     user = symtab_search(&policydb->p_users, username);
     if (!user)
         goto out_unlock;
 
     usercon.user = user->value;
 
     ebitmap_for_each_positive_bit(&user->roles, rnode, i) {
         role = policydb->role_val_to_struct[i];
         usercon.role = i + 1;
         ebitmap_for_each_positive_bit(&role->types, tnode, j) {
             usercon.type = j + 1;
 
             if (mls_setup_user_range(policydb, fromcon, user,
                          &usercon))
                 continue;
 
             rc = sidtab_context_to_sid(sidtab, &usercon, &sid);
             if (rc == -ESTALE) {
                 rcu_read_unlock();
                 goto retry;
             }
             if (rc)
                 goto out_unlock;
             if (mynel < maxnel) {
                 mysids[mynel++] = sid;
             } else {
                 rc = -ENOMEM;
                 maxnel += SIDS_NEL;
                 mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC);
                 if (!mysids2)
                     goto out_unlock;
                 memcpy(mysids2, mysids, mynel * sizeof(*mysids2));
                 kfree(mysids);
                 mysids = mysids2;
                 mysids[mynel++] = sid;
             }
         }
     }
     rc = 0;
 out_unlock:
     rcu_read_unlock();
     if (rc || !mynel) {
         kfree(mysids);
         return rc;
     }
 
     rc = -ENOMEM;
     mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL);
     if (!mysids2) {
         kfree(mysids);
         return rc;
     }
     for (i = 0, j = 0; i < mynel; i++) {
         struct av_decision dummy_avd;
         rc = avc_has_perm_noaudit(state,
                       fromsid, mysids[i],
                       SECCLASS_PROCESS, /* kernel value */
                       PROCESS__TRANSITION, AVC_STRICT,
                       &dummy_avd);
         if (!rc)
             mysids2[j++] = mysids[i];
         cond_resched();
     }
     kfree(mysids);
     *sids = mysids2;
     *nel = j;
     return 0;
 }
 
 /**
  * __security_genfs_sid - Helper to obtain a SID for a file in a filesystem
  * @policy: policy
  * @fstype: filesystem type
  * @path: path from root of mount
  * @orig_sclass: file security class
  * @sid: SID for path
  *
  * Obtain a SID to use for a file in a filesystem that
  * cannot support xattr or use a fixed labeling behavior like
  * transition SIDs or task SIDs.
  *
  * WARNING: This function may return -ESTALE, indicating that the caller
  * must retry the operation after re-acquiring the policy pointer!
  */
 static inline int __security_genfs_sid(struct selinux_policy *policy,
                        const char *fstype,
                        const char *path,
                        u16 orig_sclass,
                        u32 *sid)
 {
     struct policydb *policydb = &policy->policydb;
     struct sidtab *sidtab = policy->sidtab;
     int len;
     u16 sclass;
     struct genfs *genfs;
     struct ocontext *c;
     int cmp = 0;
 
     while (path[0] == '/' && path[1] == '/')
         path++;
 
     sclass = unmap_class(&policy->map, orig_sclass);
     *sid = SECINITSID_UNLABELED;
 
     for (genfs = policydb->genfs; genfs; genfs = genfs->next) {
         cmp = strcmp(fstype, genfs->fstype);
         if (cmp <= 0)
             break;
     }
 
     if (!genfs || cmp)
         return -ENOENT;
 
     for (c = genfs->head; c; c = c->next) {
         len = strlen(c->u.name);
         if ((!c->v.sclass || sclass == c->v.sclass) &&
             (strncmp(c->u.name, path, len) == 0))
             break;
     }
 
     if (!c)
         return -ENOENT;
 
     return ocontext_to_sid(sidtab, c, 0, sid);
 }
 
 /**
  * security_genfs_sid - Obtain a SID for a file in a filesystem
  * @state: SELinux state
  * @fstype: filesystem type
  * @path: path from root of mount
  * @orig_sclass: file security class
  * @sid: SID for path
  *
  * Acquire policy_rwlock before calling __security_genfs_sid() and release
  * it afterward.
  */
 int security_genfs_sid(struct selinux_state *state,
                const char *fstype,
                const char *path,
                u16 orig_sclass,
                u32 *sid)
 {
     struct selinux_policy *policy;
     int retval;
 
     if (!selinux_initialized(state)) {
         *sid = SECINITSID_UNLABELED;
         return 0;
     }
 
     do {
         rcu_read_lock();
         policy = rcu_dereference(state->policy);
         retval = __security_genfs_sid(policy, fstype, path,
                           orig_sclass, sid);
         rcu_read_unlock();
     } while (retval == -ESTALE);
     return retval;
 }
 
 int selinux_policy_genfs_sid(struct selinux_policy *policy,
             const char *fstype,
             const char *path,
             u16 orig_sclass,
             u32 *sid)
 {
     /* no lock required, policy is not yet accessible by other threads */
     return __security_genfs_sid(policy, fstype, path, orig_sclass, sid);
 }
 
 /**
  * security_fs_use - Determine how to handle labeling for a filesystem.
  * @state: SELinux state
  * @sb: superblock in question
  */
 int security_fs_use(struct selinux_state *state, struct super_block *sb)
 {
     struct selinux_policy *policy;
     struct policydb *policydb;
     struct sidtab *sidtab;
     int rc;
     struct ocontext *c;
     struct superblock_security_struct *sbsec = selinux_superblock(sb);
     const char *fstype = sb->s_type->name;
 
     if (!selinux_initialized(state)) {
         sbsec->behavior = SECURITY_FS_USE_NONE;
         sbsec->sid = SECINITSID_UNLABELED;
         return 0;
     }
 
 retry:
     rcu_read_lock();
     policy = rcu_dereference(state->policy);
     policydb = &policy->policydb;
     sidtab = policy->sidtab;
 
     c = policydb->ocontexts[OCON_FSUSE];
     while (c) {
         if (strcmp(fstype, c->u.name) == 0)
             break;
         c = c->next;
     }
 
     if (c) {
         sbsec->behavior = c->v.behavior;
         rc = ocontext_to_sid(sidtab, c, 0, &sbsec->sid);
         if (rc == -ESTALE) {
             rcu_read_unlock();
             goto retry;
         }
         if (rc)
             goto out;
     } else {
         rc = __security_genfs_sid(policy, fstype, "/",
                     SECCLASS_DIR, &sbsec->sid);
         if (rc == -ESTALE) {
             rcu_read_unlock();
             goto retry;
         }
         if (rc) {
             sbsec->behavior = SECURITY_FS_USE_NONE;
             rc = 0;
         } else {
             sbsec->behavior = SECURITY_FS_USE_GENFS;
         }
     }
 
 out:
     rcu_read_unlock();
     return rc;
 }
 
 int security_get_bools(struct selinux_policy *policy,
                u32 *len, char ***names, int **values)
 {
     struct policydb *policydb;
     u32 i;
     int rc;
 
     policydb = &policy->policydb;
 
     *names = NULL;
     *values = NULL;
 
     rc = 0;
     *len = policydb->p_bools.nprim;
     if (!*len)
         goto out;
 
     rc = -ENOMEM;
     *names = kcalloc(*len, sizeof(char *), GFP_ATOMIC);
     if (!*names)
         goto err;
 
     rc = -ENOMEM;
     *values = kcalloc(*len, sizeof(int), GFP_ATOMIC);
     if (!*values)
         goto err;
 
     for (i = 0; i < *len; i++) {
         (*values)[i] = policydb->bool_val_to_struct[i]->state;
 
         rc = -ENOMEM;
         (*names)[i] = kstrdup(sym_name(policydb, SYM_BOOLS, i),
                       GFP_ATOMIC);
         if (!(*names)[i])
             goto err;
     }
     rc = 0;
 out:
     return rc;
 err:
     if (*names) {
         for (i = 0; i < *len; i++)
             kfree((*names)[i]);
         kfree(*names);
     }
     kfree(*values);
     *len = 0;
     *names = NULL;
     *values = NULL;
     goto out;
 }
 
 
 int security_set_bools(struct selinux_state *state, u32 len, int *values)
 {
     struct selinux_policy *newpolicy, *oldpolicy;
     int rc;
     u32 i, seqno = 0;
 
     if (!selinux_initialized(state))
         return -EINVAL;
 
     oldpolicy = rcu_dereference_protected(state->policy,
                     lockdep_is_held(&state->policy_mutex));
 
     /* Consistency check on number of booleans, should never fail */
     if (WARN_ON(len != oldpolicy->policydb.p_bools.nprim))
         return -EINVAL;
 
     newpolicy = kmemdup(oldpolicy, sizeof(*newpolicy), GFP_KERNEL);
     if (!newpolicy)
         return -ENOMEM;
 
     /*
      * Deep copy only the parts of the policydb that might be
      * modified as a result of changing booleans.
      */
     rc = cond_policydb_dup(&newpolicy->policydb, &oldpolicy->policydb);
     if (rc) {
         kfree(newpolicy);
         return -ENOMEM;
     }
 
     /* Update the boolean states in the copy */
     for (i = 0; i < len; i++) {
         int new_state = !!values[i];
         int old_state = newpolicy->policydb.bool_val_to_struct[i]->state;
 
         if (new_state != old_state) {
             audit_log(audit_context(), GFP_ATOMIC,
                 AUDIT_MAC_CONFIG_CHANGE,
                 "bool=%s val=%d old_val=%d auid=%u ses=%u",
                 sym_name(&newpolicy->policydb, SYM_BOOLS, i),
                 new_state,
                 old_state,
                 from_kuid(&init_user_ns, audit_get_loginuid(current)),
                 audit_get_sessionid(current));
             newpolicy->policydb.bool_val_to_struct[i]->state = new_state;
         }
     }
 
     /* Re-evaluate the conditional rules in the copy */
     evaluate_cond_nodes(&newpolicy->policydb);
 
     /* Set latest granting seqno for new policy */
     newpolicy->latest_granting = oldpolicy->latest_granting + 1;
     seqno = newpolicy->latest_granting;
 
     /* Install the new policy */
     rcu_assign_pointer(state->policy, newpolicy);
 
     /*
      * Free the conditional portions of the old policydb
      * that were copied for the new policy, and the oldpolicy
      * structure itself but not what it references.
      */
     synchronize_rcu();
     selinux_policy_cond_free(oldpolicy);
 
     /* Notify others of the policy change */
     selinux_notify_policy_change(state, seqno);
     return 0;
 }
 
 int security_get_bool_value(struct selinux_state *state,
                 u32 index)
 {
     struct selinux_policy *policy;
     struct policydb *policydb;
     int rc;
     u32 len;
 
     if (!selinux_initialized(state))
         return 0;
 
     rcu_read_lock();
     policy = rcu_dereference(state->policy);
     policydb = &policy->policydb;
 
     rc = -EFAULT;
     len = policydb->p_bools.nprim;
     if (index >= len)
         goto out;
 
     rc = policydb->bool_val_to_struct[index]->state;
 out:
     rcu_read_unlock();
     return rc;
 }
 
 static int security_preserve_bools(struct selinux_policy *oldpolicy,
                 struct selinux_policy *newpolicy)
 {
     int rc, *bvalues = NULL;
     char **bnames = NULL;
     struct cond_bool_datum *booldatum;
     u32 i, nbools = 0;
 
     rc = security_get_bools(oldpolicy, &nbools, &bnames, &bvalues);
     if (rc)
         goto out;
     for (i = 0; i < nbools; i++) {
         booldatum = symtab_search(&newpolicy->policydb.p_bools,
                     bnames[i]);
         if (booldatum)
             booldatum->state = bvalues[i];
     }
     evaluate_cond_nodes(&newpolicy->policydb);
 
 out:
     if (bnames) {
         for (i = 0; i < nbools; i++)
             kfree(bnames[i]);
     }
     kfree(bnames);
     kfree(bvalues);
     return rc;
 }
 
 /*
  * security_sid_mls_copy() - computes a new sid based on the given
  * sid and the mls portion of mls_sid.
  */
 int security_sid_mls_copy(struct selinux_state *state,
               u32 sid, u32 mls_sid, u32 *new_sid)
 {
     struct selinux_policy *policy;
     struct policydb *policydb;
     struct sidtab *sidtab;
     struct context *context1;
     struct context *context2;
     struct context newcon;
     char *s;
     u32 len;
     int rc;
 
     if (!selinux_initialized(state)) {
         *new_sid = sid;
         return 0;
     }
 
 retry:
     rc = 0;
     context_init(&newcon);
 
     rcu_read_lock();
     policy = rcu_dereference(state->policy);
     policydb = &policy->policydb;
     sidtab = policy->sidtab;
 
     if (!policydb->mls_enabled) {
         *new_sid = sid;
         goto out_unlock;
     }
 
     rc = -EINVAL;
     context1 = sidtab_search(sidtab, sid);
     if (!context1) {
         pr_err("SELinux: %s:  unrecognized SID %d\n",
             __func__, sid);
         goto out_unlock;
     }
 
     rc = -EINVAL;
     context2 = sidtab_search(sidtab, mls_sid);
     if (!context2) {
         pr_err("SELinux: %s:  unrecognized SID %d\n",
             __func__, mls_sid);
         goto out_unlock;
     }
 
     newcon.user = context1->user;
     newcon.role = context1->role;
     newcon.type = context1->type;
     rc = mls_context_cpy(&newcon, context2);
     if (rc)
         goto out_unlock;
 
     /* Check the validity of the new context. */
     if (!policydb_context_isvalid(policydb, &newcon)) {
         rc = convert_context_handle_invalid_context(state, policydb,
                             &newcon);
         if (rc) {
             if (!context_struct_to_string(policydb, &newcon, &s,
                               &len)) {
                 struct audit_buffer *ab;
 
                 ab = audit_log_start(audit_context(),
                              GFP_ATOMIC,
                              AUDIT_SELINUX_ERR);
                 audit_log_format(ab,
                          "op=security_sid_mls_copy invalid_context=");
                 /* don't record NUL with untrusted strings */
                 audit_log_n_untrustedstring(ab, s, len - 1);
                 audit_log_end(ab);
                 kfree(s);
             }
             goto out_unlock;
         }
     }
     rc = sidtab_context_to_sid(sidtab, &newcon, new_sid);
     if (rc == -ESTALE) {
         rcu_read_unlock();
         context_destroy(&newcon);
         goto retry;
     }
 out_unlock:
     rcu_read_unlock();
     context_destroy(&newcon);
     return rc;
 }
 
 /**
  * security_net_peersid_resolve - Compare and resolve two network peer SIDs
  * @state: SELinux state
  * @nlbl_sid: NetLabel SID
  * @nlbl_type: NetLabel labeling protocol type
  * @xfrm_sid: XFRM SID
  * @peer_sid: network peer sid
  *
  * Description:
  * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be
  * resolved into a single SID it is returned via @peer_sid and the function
  * returns zero.  Otherwise @peer_sid is set to SECSID_NULL and the function
  * returns a negative value.  A table summarizing the behavior is below:
  *
  *                                 | function return |      @sid
  *   ------------------------------+-----------------+-----------------
  *   no peer labels                |        0        |    SECSID_NULL
  *   single peer label             |        0        |    <peer_label>
  *   multiple, consistent labels   |        0        |    <peer_label>
  *   multiple, inconsistent labels |    -<errno>     |    SECSID_NULL
  *
  */
 int security_net_peersid_resolve(struct selinux_state *state,
                  u32 nlbl_sid, u32 nlbl_type,
                  u32 xfrm_sid,
                  u32 *peer_sid)
 {
     struct selinux_policy *policy;
     struct policydb *policydb;
     struct sidtab *sidtab;
     int rc;
     struct context *nlbl_ctx;
     struct context *xfrm_ctx;
 
     *peer_sid = SECSID_NULL;
 
     /* handle the common (which also happens to be the set of easy) cases
      * right away, these two if statements catch everything involving a
      * single or absent peer SID/label */
     if (xfrm_sid == SECSID_NULL) {
         *peer_sid = nlbl_sid;
         return 0;
     }
     /* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label
      * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label
      * is present */
     if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) {
         *peer_sid = xfrm_sid;
         return 0;
     }
 
     if (!selinux_initialized(state))
         return 0;
 
     rcu_read_lock();
     policy = rcu_dereference(state->policy);
     policydb = &policy->policydb;
     sidtab = policy->sidtab;
 
     /*
      * We don't need to check initialized here since the only way both
      * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the
      * security server was initialized and state->initialized was true.
      */
     if (!policydb->mls_enabled) {
         rc = 0;
         goto out;
     }
 
     rc = -EINVAL;
     nlbl_ctx = sidtab_search(sidtab, nlbl_sid);
     if (!nlbl_ctx) {
         pr_err("SELinux: %s:  unrecognized SID %d\n",
                __func__, nlbl_sid);
         goto out;
     }
     rc = -EINVAL;
     xfrm_ctx = sidtab_search(sidtab, xfrm_sid);
     if (!xfrm_ctx) {
         pr_err("SELinux: %s:  unrecognized SID %d\n",
                __func__, xfrm_sid);
         goto out;
     }
     rc = (mls_context_cmp(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES);
     if (rc)
         goto out;
 
     /* at present NetLabel SIDs/labels really only carry MLS
      * information so if the MLS portion of the NetLabel SID
      * matches the MLS portion of the labeled XFRM SID/label
      * then pass along the XFRM SID as it is the most
      * expressive */
     *peer_sid = xfrm_sid;
 out:
     rcu_read_unlock();
     return rc;
 }
 
 static int get_classes_callback(void *k, void *d, void *args)
 {
     struct class_datum *datum = d;
     char *name = k, **classes = args;
     int value = datum->value - 1;
 
     classes[value] = kstrdup(name, GFP_ATOMIC);
     if (!classes[value])
         return -ENOMEM;
 
     return 0;
 }
 
 int security_get_classes(struct selinux_policy *policy,
              char ***classes, int *nclasses)
 {
     struct policydb *policydb;
     int rc;
 
     policydb = &policy->policydb;
 
     rc = -ENOMEM;
     *nclasses = policydb->p_classes.nprim;
     *classes = kcalloc(*nclasses, sizeof(**classes), GFP_ATOMIC);
     if (!*classes)
         goto out;
 
     rc = hashtab_map(&policydb->p_classes.table, get_classes_callback,
              *classes);
     if (rc) {
         int i;
         for (i = 0; i < *nclasses; i++)
             kfree((*classes)[i]);
         kfree(*classes);
     }
 
 out:
     return rc;
 }
 
 static int get_permissions_callback(void *k, void *d, void *args)
 {
     struct perm_datum *datum = d;
     char *name = k, **perms = args;
     int value = datum->value - 1;
 
     perms[value] = kstrdup(name, GFP_ATOMIC);
     if (!perms[value])
         return -ENOMEM;
 
     return 0;
 }
 
 int security_get_permissions(struct selinux_policy *policy,
                  char *class, char ***perms, int *nperms)
 {
     struct policydb *policydb;
     int rc, i;
     struct class_datum *match;
 
     policydb = &policy->policydb;
 
     rc = -EINVAL;
     match = symtab_search(&policydb->p_classes, class);
     if (!match) {
         pr_err("SELinux: %s:  unrecognized class %s\n",
             __func__, class);
         goto out;
     }
 
     rc = -ENOMEM;
     *nperms = match->permissions.nprim;
     *perms = kcalloc(*nperms, sizeof(**perms), GFP_ATOMIC);
     if (!*perms)
         goto out;
 
     if (match->comdatum) {
         rc = hashtab_map(&match->comdatum->permissions.table,
                  get_permissions_callback, *perms);
         if (rc)
             goto err;
     }
 
     rc = hashtab_map(&match->permissions.table, get_permissions_callback,
              *perms);
     if (rc)
         goto err;
 
 out:
     return rc;
 
 err:
     for (i = 0; i < *nperms; i++)
         kfree((*perms)[i]);
     kfree(*perms);
     return rc;
 }
 
 int security_get_reject_unknown(struct selinux_state *state)
 {
     struct selinux_policy *policy;
     int value;
 
     if (!selinux_initialized(state))
         return 0;
 
     rcu_read_lock();
     policy = rcu_dereference(state->policy);
     value = policy->policydb.reject_unknown;
     rcu_read_unlock();
     return value;
 }
 
 int security_get_allow_unknown(struct selinux_state *state)
 {
     struct selinux_policy *policy;
     int value;
 
     if (!selinux_initialized(state))
         return 0;
 
     rcu_read_lock();
     policy = rcu_dereference(state->policy);
     value = policy->policydb.allow_unknown;
     rcu_read_unlock();
     return value;
 }
 
 /**
  * security_policycap_supported - Check for a specific policy capability
  * @state: SELinux state
  * @req_cap: capability
  *
  * Description:
  * This function queries the currently loaded policy to see if it supports the
  * capability specified by @req_cap.  Returns true (1) if the capability is
  * supported, false (0) if it isn't supported.
  *
  */
 int security_policycap_supported(struct selinux_state *state,
                  unsigned int req_cap)
 {
     struct selinux_policy *policy;
     int rc;
 
     if (!selinux_initialized(state))
         return 0;
 
     rcu_read_lock();
     policy = rcu_dereference(state->policy);
     rc = ebitmap_get_bit(&policy->policydb.policycaps, req_cap);
     rcu_read_unlock();
 
     return rc;
 }
 
 struct selinux_audit_rule {
     u32 au_seqno;
     struct context au_ctxt;
 };
 
 void selinux_audit_rule_free(void *vrule)
 {
     struct selinux_audit_rule *rule = vrule;
 
     if (rule) {
         context_destroy(&rule->au_ctxt);
         kfree(rule);
     }
 }
 
 int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
 {
     struct selinux_state *state = &selinux_state;
     struct selinux_policy *policy;
     struct policydb *policydb;
     struct selinux_audit_rule *tmprule;
     struct role_datum *roledatum;
     struct type_datum *typedatum;
     struct user_datum *userdatum;
     struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule;
     int rc = 0;
 
     *rule = NULL;
 
     if (!selinux_initialized(state))
         return -EOPNOTSUPP;
 
     switch (field) {
     case AUDIT_SUBJ_USER:
     case AUDIT_SUBJ_ROLE:
     case AUDIT_SUBJ_TYPE:
     case AUDIT_OBJ_USER:
     case AUDIT_OBJ_ROLE:
     case AUDIT_OBJ_TYPE:
         /* only 'equals' and 'not equals' fit user, role, and type */
         if (op != Audit_equal && op != Audit_not_equal)
             return -EINVAL;
         break;
     case AUDIT_SUBJ_SEN:
     case AUDIT_SUBJ_CLR:
     case AUDIT_OBJ_LEV_LOW:
     case AUDIT_OBJ_LEV_HIGH:
         /* we do not allow a range, indicated by the presence of '-' */
         if (strchr(rulestr, '-'))
             return -EINVAL;
         break;
     default:
         /* only the above fields are valid */
         return -EINVAL;
     }
 
     tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL);
     if (!tmprule)
         return -ENOMEM;
 
     context_init(&tmprule->au_ctxt);
 
     rcu_read_lock();
     policy = rcu_dereference(state->policy);
     policydb = &policy->policydb;
 
     tmprule->au_seqno = policy->latest_granting;
 
     switch (field) {
     case AUDIT_SUBJ_USER:
     case AUDIT_OBJ_USER:
         rc = -EINVAL;
         userdatum = symtab_search(&policydb->p_users, rulestr);
         if (!userdatum)
             goto out;
         tmprule->au_ctxt.user = userdatum->value;
         break;
     case AUDIT_SUBJ_ROLE:
     case AUDIT_OBJ_ROLE:
         rc = -EINVAL;
         roledatum = symtab_search(&policydb->p_roles, rulestr);
         if (!roledatum)
             goto out;
         tmprule->au_ctxt.role = roledatum->value;
         break;
     case AUDIT_SUBJ_TYPE:
     case AUDIT_OBJ_TYPE:
         rc = -EINVAL;
         typedatum = symtab_search(&policydb->p_types, rulestr);
         if (!typedatum)
             goto out;
         tmprule->au_ctxt.type = typedatum->value;
         break;
     case AUDIT_SUBJ_SEN:
     case AUDIT_SUBJ_CLR:
     case AUDIT_OBJ_LEV_LOW:
     case AUDIT_OBJ_LEV_HIGH:
         rc = mls_from_string(policydb, rulestr, &tmprule->au_ctxt,
                      GFP_ATOMIC);
         if (rc)
             goto out;
         break;
     }
     rc = 0;
 out:
     rcu_read_unlock();
 
     if (rc) {
         selinux_audit_rule_free(tmprule);
         tmprule = NULL;
     }
 
     *rule = tmprule;
 
     return rc;
 }
 
 /* Check to see if the rule contains any selinux fields */
 int selinux_audit_rule_known(struct audit_krule *rule)
 {
     int i;
 
     for (i = 0; i < rule->field_count; i++) {
         struct audit_field *f = &rule->fields[i];
         switch (f->type) {
         case AUDIT_SUBJ_USER:
         case AUDIT_SUBJ_ROLE:
         case AUDIT_SUBJ_TYPE:
         case AUDIT_SUBJ_SEN:
         case AUDIT_SUBJ_CLR:
         case AUDIT_OBJ_USER:
         case AUDIT_OBJ_ROLE:
         case AUDIT_OBJ_TYPE:
         case AUDIT_OBJ_LEV_LOW:
         case AUDIT_OBJ_LEV_HIGH:
             return 1;
         }
     }
 
     return 0;
 }
 
 int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule)
 {
     struct selinux_state *state = &selinux_state;
     struct selinux_policy *policy;
     struct context *ctxt;
     struct mls_level *level;
     struct selinux_audit_rule *rule = vrule;
     int match = 0;
 
     if (unlikely(!rule)) {
         WARN_ONCE(1, "selinux_audit_rule_match: missing rule\n");
         return -ENOENT;
     }
 
     if (!selinux_initialized(state))
         return 0;
 
     rcu_read_lock();
 
     policy = rcu_dereference(state->policy);
 
     if (rule->au_seqno < policy->latest_granting) {
         match = -ESTALE;
         goto out;
     }
 
     ctxt = sidtab_search(policy->sidtab, sid);
     if (unlikely(!ctxt)) {
         WARN_ONCE(1, "selinux_audit_rule_match: unrecognized SID %d\n",
               sid);
         match = -ENOENT;
         goto out;
     }
 
     /* a field/op pair that is not caught here will simply fall through
        without a match */
     switch (field) {
     case AUDIT_SUBJ_USER:
     case AUDIT_OBJ_USER:
         switch (op) {
         case Audit_equal:
             match = (ctxt->user == rule->au_ctxt.user);
             break;
         case Audit_not_equal:
             match = (ctxt->user != rule->au_ctxt.user);
             break;
         }
         break;
     case AUDIT_SUBJ_ROLE:
     case AUDIT_OBJ_ROLE:
         switch (op) {
         case Audit_equal:
             match = (ctxt->role == rule->au_ctxt.role);
             break;
         case Audit_not_equal:
             match = (ctxt->role != rule->au_ctxt.role);
             break;
         }
         break;
     case AUDIT_SUBJ_TYPE:
     case AUDIT_OBJ_TYPE:
         switch (op) {
         case Audit_equal:
             match = (ctxt->type == rule->au_ctxt.type);
             break;
         case Audit_not_equal:
             match = (ctxt->type != rule->au_ctxt.type);
             break;
         }
         break;
     case AUDIT_SUBJ_SEN:
     case AUDIT_SUBJ_CLR:
     case AUDIT_OBJ_LEV_LOW:
     case AUDIT_OBJ_LEV_HIGH:
         level = ((field == AUDIT_SUBJ_SEN ||
               field == AUDIT_OBJ_LEV_LOW) ?
              &ctxt->range.level[0] : &ctxt->range.level[1]);
         switch (op) {
         case Audit_equal:
             match = mls_level_eq(&rule->au_ctxt.range.level[0],
                          level);
             break;
         case Audit_not_equal:
             match = !mls_level_eq(&rule->au_ctxt.range.level[0],
                           level);
             break;
         case Audit_lt:
             match = (mls_level_dom(&rule->au_ctxt.range.level[0],
                            level) &&
                  !mls_level_eq(&rule->au_ctxt.range.level[0],
                            level));
             break;
         case Audit_le:
             match = mls_level_dom(&rule->au_ctxt.range.level[0],
                           level);
             break;
         case Audit_gt:
             match = (mls_level_dom(level,
                           &rule->au_ctxt.range.level[0]) &&
                  !mls_level_eq(level,
                            &rule->au_ctxt.range.level[0]));
             break;
         case Audit_ge:
             match = mls_level_dom(level,
                           &rule->au_ctxt.range.level[0]);
             break;
         }
     }
 
 out:
     rcu_read_unlock();
     return match;
 }
 
 static int aurule_avc_callback(u32 event)
 {
     if (event == AVC_CALLBACK_RESET)
         return audit_update_lsm_rules();
     return 0;
 }
 
 static int __init aurule_init(void)
 {
     int err;
 
     err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET);
     if (err)
         panic("avc_add_callback() failed, error %d\n", err);
 
     return err;
 }
 __initcall(aurule_init);
 
 #ifdef CONFIG_NETLABEL
 /**
  * security_netlbl_cache_add - Add an entry to the NetLabel cache
  * @secattr: the NetLabel packet security attributes
  * @sid: the SELinux SID
  *
  * Description:
  * Attempt to cache the context in @ctx, which was derived from the packet in
  * @skb, in the NetLabel subsystem cache.  This function assumes @secattr has
  * already been initialized.
  *
  */
 static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr,
                       u32 sid)
 {
     u32 *sid_cache;
 
     sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC);
     if (sid_cache == NULL)
         return;
     secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC);
     if (secattr->cache == NULL) {
         kfree(sid_cache);
         return;
     }
 
     *sid_cache = sid;
     secattr->cache->free = kfree;
     secattr->cache->data = sid_cache;
     secattr->flags |= NETLBL_SECATTR_CACHE;
 }
 
 /**
  * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID
  * @state: SELinux state
  * @secattr: the NetLabel packet security attributes
  * @sid: the SELinux SID
  *
  * Description:
  * Convert the given NetLabel security attributes in @secattr into a
  * SELinux SID.  If the @secattr field does not contain a full SELinux
  * SID/context then use SECINITSID_NETMSG as the foundation.  If possible the
  * 'cache' field of @secattr is set and the CACHE flag is set; this is to
  * allow the @secattr to be used by NetLabel to cache the secattr to SID
  * conversion for future lookups.  Returns zero on success, negative values on
  * failure.
  *
  */
 int security_netlbl_secattr_to_sid(struct selinux_state *state,
                    struct netlbl_lsm_secattr *secattr,
                    u32 *sid)
 {
     struct selinux_policy *policy;
     struct policydb *policydb;
     struct sidtab *sidtab;
     int rc;
     struct context *ctx;
     struct context ctx_new;
 
     if (!selinux_initialized(state)) {
         *sid = SECSID_NULL;
         return 0;
     }
 
 retry:
     rc = 0;
     rcu_read_lock();
     policy = rcu_dereference(state->policy);
     policydb = &policy->policydb;
     sidtab = policy->sidtab;
 
     if (secattr->flags & NETLBL_SECATTR_CACHE)
         *sid = *(u32 *)secattr->cache->data;
     else if (secattr->flags & NETLBL_SECATTR_SECID)
         *sid = secattr->attr.secid;
     else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
         rc = -EIDRM;
         ctx = sidtab_search(sidtab, SECINITSID_NETMSG);
         if (ctx == NULL)
             goto out;
 
         context_init(&ctx_new);
         ctx_new.user = ctx->user;
         ctx_new.role = ctx->role;
         ctx_new.type = ctx->type;
         mls_import_netlbl_lvl(policydb, &ctx_new, secattr);
         if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
             rc = mls_import_netlbl_cat(policydb, &ctx_new, secattr);
             if (rc)
                 goto out;
         }
         rc = -EIDRM;
         if (!mls_context_isvalid(policydb, &ctx_new)) {
             ebitmap_destroy(&ctx_new.range.level[0].cat);
             goto out;
         }
 
         rc = sidtab_context_to_sid(sidtab, &ctx_new, sid);
         ebitmap_destroy(&ctx_new.range.level[0].cat);
         if (rc == -ESTALE) {
             rcu_read_unlock();
             goto retry;
         }
         if (rc)
             goto out;
 
         security_netlbl_cache_add(secattr, *sid);
     } else
         *sid = SECSID_NULL;
 
 out:
     rcu_read_unlock();
     return rc;
 }
 
 /**
  * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr
  * @state: SELinux state
  * @sid: the SELinux SID
  * @secattr: the NetLabel packet security attributes
  *
  * Description:
  * Convert the given SELinux SID in @sid into a NetLabel security attribute.
  * Returns zero on success, negative values on failure.
  *
  */
 int security_netlbl_sid_to_secattr(struct selinux_state *state,
                    u32 sid, struct netlbl_lsm_secattr *secattr)
 {
     struct selinux_policy *policy;
     struct policydb *policydb;
     int rc;
     struct context *ctx;
 
     if (!selinux_initialized(state))
         return 0;
 
     rcu_read_lock();
     policy = rcu_dereference(state->policy);
     policydb = &policy->policydb;
 
     rc = -ENOENT;
     ctx = sidtab_search(policy->sidtab, sid);
     if (ctx == NULL)
         goto out;
 
     rc = -ENOMEM;
     secattr->domain = kstrdup(sym_name(policydb, SYM_TYPES, ctx->type - 1),
                   GFP_ATOMIC);
     if (secattr->domain == NULL)
         goto out;
 
     secattr->attr.secid = sid;
     secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID;
     mls_export_netlbl_lvl(policydb, ctx, secattr);
     rc = mls_export_netlbl_cat(policydb, ctx, secattr);
 out:
     rcu_read_unlock();
     return rc;
 }
 #endif /* CONFIG_NETLABEL */
 
 /**
  * __security_read_policy - read the policy.
  * @policy: SELinux policy
  * @data: binary policy data
  * @len: length of data in bytes
  *
  */
 static int __security_read_policy(struct selinux_policy *policy,
                   void *data, size_t *len)
 {
     int rc;
     struct policy_file fp;
 
     fp.data = data;
     fp.len = *len;
 
     rc = policydb_write(&policy->policydb, &fp);
     if (rc)
         return rc;
 
     *len = (unsigned long)fp.data - (unsigned long)data;
     return 0;
 }
 
 /**
  * security_read_policy - read the policy.
  * @state: selinux_state
  * @data: binary policy data
  * @len: length of data in bytes
  *
  */
 int security_read_policy(struct selinux_state *state,
              void **data, size_t *len)
 {
     struct selinux_policy *policy;
 
     policy = rcu_dereference_protected(
             state->policy, lockdep_is_held(&state->policy_mutex));
     if (!policy)
         return -EINVAL;
 
     *len = policy->policydb.len;
     *data = vmalloc_user(*len);
     if (!*data)
         return -ENOMEM;
 
     return __security_read_policy(policy, *data, len);
 }
 
 /**
  * security_read_state_kernel - read the policy.
  * @state: selinux_state
  * @data: binary policy data
  * @len: length of data in bytes
  *
  * Allocates kernel memory for reading SELinux policy.
  * This function is for internal use only and should not
  * be used for returning data to user space.
  *
  * This function must be called with policy_mutex held.
  */
 int security_read_state_kernel(struct selinux_state *state,
                    void **data, size_t *len)
 {
     int err;
     struct selinux_policy *policy;
 
     policy = rcu_dereference_protected(
             state->policy, lockdep_is_held(&state->policy_mutex));
     if (!policy)
         return -EINVAL;
 
     *len = policy->policydb.len;
     *data = vmalloc(*len);
     if (!*data)
         return -ENOMEM;
 
     err = __security_read_policy(policy, *data, len);
     if (err) {
         vfree(*data);
         *data = NULL;
         *len = 0;
     }
     return err;
 }