Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / security / apparmor / domain.c
diff --git a/kernel/security/apparmor/domain.c b/kernel/security/apparmor/domain.c
new file mode 100644 (file)
index 0000000..d97cba3
--- /dev/null
@@ -0,0 +1,854 @@
+/*
+ * AppArmor security module
+ *
+ * This file contains AppArmor policy attachment and domain transitions
+ *
+ * Copyright (C) 2002-2008 Novell/SUSE
+ * Copyright 2009-2010 Canonical Ltd.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation, version 2 of the
+ * License.
+ */
+
+#include <linux/errno.h>
+#include <linux/fdtable.h>
+#include <linux/file.h>
+#include <linux/mount.h>
+#include <linux/syscalls.h>
+#include <linux/tracehook.h>
+#include <linux/personality.h>
+
+#include "include/audit.h"
+#include "include/apparmorfs.h"
+#include "include/context.h"
+#include "include/domain.h"
+#include "include/file.h"
+#include "include/ipc.h"
+#include "include/match.h"
+#include "include/path.h"
+#include "include/policy.h"
+
+/**
+ * aa_free_domain_entries - free entries in a domain table
+ * @domain: the domain table to free  (MAYBE NULL)
+ */
+void aa_free_domain_entries(struct aa_domain *domain)
+{
+       int i;
+       if (domain) {
+               if (!domain->table)
+                       return;
+
+               for (i = 0; i < domain->size; i++)
+                       kzfree(domain->table[i]);
+               kzfree(domain->table);
+               domain->table = NULL;
+       }
+}
+
+/**
+ * may_change_ptraced_domain - check if can change profile on ptraced task
+ * @to_profile: profile to change to  (NOT NULL)
+ *
+ * Check if current is ptraced and if so if the tracing task is allowed
+ * to trace the new domain
+ *
+ * Returns: %0 or error if change not allowed
+ */
+static int may_change_ptraced_domain(struct aa_profile *to_profile)
+{
+       struct task_struct *tracer;
+       struct aa_profile *tracerp = NULL;
+       int error = 0;
+
+       rcu_read_lock();
+       tracer = ptrace_parent(current);
+       if (tracer)
+               /* released below */
+               tracerp = aa_get_task_profile(tracer);
+
+       /* not ptraced */
+       if (!tracer || unconfined(tracerp))
+               goto out;
+
+       error = aa_may_ptrace(tracerp, to_profile, PTRACE_MODE_ATTACH);
+
+out:
+       rcu_read_unlock();
+       aa_put_profile(tracerp);
+
+       return error;
+}
+
+/**
+ * change_profile_perms - find permissions for change_profile
+ * @profile: the current profile  (NOT NULL)
+ * @ns: the namespace being switched to  (NOT NULL)
+ * @name: the name of the profile to change to  (NOT NULL)
+ * @request: requested perms
+ * @start: state to start matching in
+ *
+ * Returns: permission set
+ */
+static struct file_perms change_profile_perms(struct aa_profile *profile,
+                                             struct aa_namespace *ns,
+                                             const char *name, u32 request,
+                                             unsigned int start)
+{
+       struct file_perms perms;
+       struct path_cond cond = { };
+       unsigned int state;
+
+       if (unconfined(profile)) {
+               perms.allow = AA_MAY_CHANGE_PROFILE | AA_MAY_ONEXEC;
+               perms.audit = perms.quiet = perms.kill = 0;
+               return perms;
+       } else if (!profile->file.dfa) {
+               return nullperms;
+       } else if ((ns == profile->ns)) {
+               /* try matching against rules with out namespace prepended */
+               aa_str_perms(profile->file.dfa, start, name, &cond, &perms);
+               if (COMBINED_PERM_MASK(perms) & request)
+                       return perms;
+       }
+
+       /* try matching with namespace name and then profile */
+       state = aa_dfa_match(profile->file.dfa, start, ns->base.name);
+       state = aa_dfa_match_len(profile->file.dfa, state, ":", 1);
+       aa_str_perms(profile->file.dfa, state, name, &cond, &perms);
+
+       return perms;
+}
+
+/**
+ * __attach_match_ - find an attachment match
+ * @name - to match against  (NOT NULL)
+ * @head - profile list to walk  (NOT NULL)
+ *
+ * Do a linear search on the profiles in the list.  There is a matching
+ * preference where an exact match is preferred over a name which uses
+ * expressions to match, and matching expressions with the greatest
+ * xmatch_len are preferred.
+ *
+ * Requires: @head not be shared or have appropriate locks held
+ *
+ * Returns: profile or NULL if no match found
+ */
+static struct aa_profile *__attach_match(const char *name,
+                                        struct list_head *head)
+{
+       int len = 0;
+       struct aa_profile *profile, *candidate = NULL;
+
+       list_for_each_entry_rcu(profile, head, base.list) {
+               if (profile->flags & PFLAG_NULL)
+                       continue;
+               if (profile->xmatch && profile->xmatch_len > len) {
+                       unsigned int state = aa_dfa_match(profile->xmatch,
+                                                         DFA_START, name);
+                       u32 perm = dfa_user_allow(profile->xmatch, state);
+                       /* any accepting state means a valid match. */
+                       if (perm & MAY_EXEC) {
+                               candidate = profile;
+                               len = profile->xmatch_len;
+                       }
+               } else if (!strcmp(profile->base.name, name))
+                       /* exact non-re match, no more searching required */
+                       return profile;
+       }
+
+       return candidate;
+}
+
+/**
+ * find_attach - do attachment search for unconfined processes
+ * @ns: the current namespace  (NOT NULL)
+ * @list: list to search  (NOT NULL)
+ * @name: the executable name to match against  (NOT NULL)
+ *
+ * Returns: profile or NULL if no match found
+ */
+static struct aa_profile *find_attach(struct aa_namespace *ns,
+                                     struct list_head *list, const char *name)
+{
+       struct aa_profile *profile;
+
+       rcu_read_lock();
+       profile = aa_get_profile(__attach_match(name, list));
+       rcu_read_unlock();
+
+       return profile;
+}
+
+/**
+ * separate_fqname - separate the namespace and profile names
+ * @fqname: the fqname name to split  (NOT NULL)
+ * @ns_name: the namespace name if it exists  (NOT NULL)
+ *
+ * This is the xtable equivalent routine of aa_split_fqname.  It finds the
+ * split in an xtable fqname which contains an embedded \0 instead of a :
+ * if a namespace is specified.  This is done so the xtable is constant and
+ * isn't re-split on every lookup.
+ *
+ * Either the profile or namespace name may be optional but if the namespace
+ * is specified the profile name termination must be present.  This results
+ * in the following possible encodings:
+ * profile_name\0
+ * :ns_name\0profile_name\0
+ * :ns_name\0\0
+ *
+ * NOTE: the xtable fqname is pre-validated at load time in unpack_trans_table
+ *
+ * Returns: profile name if it is specified else NULL
+ */
+static const char *separate_fqname(const char *fqname, const char **ns_name)
+{
+       const char *name;
+
+       if (fqname[0] == ':') {
+               /* In this case there is guaranteed to be two \0 terminators
+                * in the string.  They are verified at load time by
+                * by unpack_trans_table
+                */
+               *ns_name = fqname + 1;          /* skip : */
+               name = *ns_name + strlen(*ns_name) + 1;
+               if (!*name)
+                       name = NULL;
+       } else {
+               *ns_name = NULL;
+               name = fqname;
+       }
+
+       return name;
+}
+
+static const char *next_name(int xtype, const char *name)
+{
+       return NULL;
+}
+
+/**
+ * x_table_lookup - lookup an x transition name via transition table
+ * @profile: current profile (NOT NULL)
+ * @xindex: index into x transition table
+ *
+ * Returns: refcounted profile, or NULL on failure (MAYBE NULL)
+ */
+static struct aa_profile *x_table_lookup(struct aa_profile *profile, u32 xindex)
+{
+       struct aa_profile *new_profile = NULL;
+       struct aa_namespace *ns = profile->ns;
+       u32 xtype = xindex & AA_X_TYPE_MASK;
+       int index = xindex & AA_X_INDEX_MASK;
+       const char *name;
+
+       /* index is guaranteed to be in range, validated at load time */
+       for (name = profile->file.trans.table[index]; !new_profile && name;
+            name = next_name(xtype, name)) {
+               struct aa_namespace *new_ns;
+               const char *xname = NULL;
+
+               new_ns = NULL;
+               if (xindex & AA_X_CHILD) {
+                       /* release by caller */
+                       new_profile = aa_find_child(profile, name);
+                       continue;
+               } else if (*name == ':') {
+                       /* switching namespace */
+                       const char *ns_name;
+                       xname = name = separate_fqname(name, &ns_name);
+                       if (!xname)
+                               /* no name so use profile name */
+                               xname = profile->base.hname;
+                       if (*ns_name == '@') {
+                               /* TODO: variable support */
+                               ;
+                       }
+                       /* released below */
+                       new_ns = aa_find_namespace(ns, ns_name);
+                       if (!new_ns)
+                               continue;
+               } else if (*name == '@') {
+                       /* TODO: variable support */
+                       continue;
+               } else {
+                       /* basic namespace lookup */
+                       xname = name;
+               }
+
+               /* released by caller */
+               new_profile = aa_lookup_profile(new_ns ? new_ns : ns, xname);
+               aa_put_namespace(new_ns);
+       }
+
+       /* released by caller */
+       return new_profile;
+}
+
+/**
+ * x_to_profile - get target profile for a given xindex
+ * @profile: current profile  (NOT NULL)
+ * @name: name to lookup (NOT NULL)
+ * @xindex: index into x transition table
+ *
+ * find profile for a transition index
+ *
+ * Returns: refcounted profile or NULL if not found available
+ */
+static struct aa_profile *x_to_profile(struct aa_profile *profile,
+                                      const char *name, u32 xindex)
+{
+       struct aa_profile *new_profile = NULL;
+       struct aa_namespace *ns = profile->ns;
+       u32 xtype = xindex & AA_X_TYPE_MASK;
+
+       switch (xtype) {
+       case AA_X_NONE:
+               /* fail exec unless ix || ux fallback - handled by caller */
+               return NULL;
+       case AA_X_NAME:
+               if (xindex & AA_X_CHILD)
+                       /* released by caller */
+                       new_profile = find_attach(ns, &profile->base.profiles,
+                                                 name);
+               else
+                       /* released by caller */
+                       new_profile = find_attach(ns, &ns->base.profiles,
+                                                 name);
+               break;
+       case AA_X_TABLE:
+               /* released by caller */
+               new_profile = x_table_lookup(profile, xindex);
+               break;
+       }
+
+       /* released by caller */
+       return new_profile;
+}
+
+/**
+ * apparmor_bprm_set_creds - set the new creds on the bprm struct
+ * @bprm: binprm for the exec  (NOT NULL)
+ *
+ * Returns: %0 or error on failure
+ */
+int apparmor_bprm_set_creds(struct linux_binprm *bprm)
+{
+       struct aa_task_cxt *cxt;
+       struct aa_profile *profile, *new_profile = NULL;
+       struct aa_namespace *ns;
+       char *buffer = NULL;
+       unsigned int state;
+       struct file_perms perms = {};
+       struct path_cond cond = {
+               file_inode(bprm->file)->i_uid,
+               file_inode(bprm->file)->i_mode
+       };
+       const char *name = NULL, *target = NULL, *info = NULL;
+       int error = cap_bprm_set_creds(bprm);
+       if (error)
+               return error;
+
+       if (bprm->cred_prepared)
+               return 0;
+
+       cxt = cred_cxt(bprm->cred);
+       BUG_ON(!cxt);
+
+       profile = aa_get_newest_profile(cxt->profile);
+       /*
+        * get the namespace from the replacement profile as replacement
+        * can change the namespace
+        */
+       ns = profile->ns;
+       state = profile->file.start;
+
+       /* buffer freed below, name is pointer into buffer */
+       error = aa_path_name(&bprm->file->f_path, profile->path_flags, &buffer,
+                            &name, &info);
+       if (error) {
+               if (unconfined(profile) ||
+                   (profile->flags & PFLAG_IX_ON_NAME_ERROR))
+                       error = 0;
+               name = bprm->filename;
+               goto audit;
+       }
+
+       /* Test for onexec first as onexec directives override other
+        * x transitions.
+        */
+       if (unconfined(profile)) {
+               /* unconfined task */
+               if (cxt->onexec)
+                       /* change_profile on exec already been granted */
+                       new_profile = aa_get_profile(cxt->onexec);
+               else
+                       new_profile = find_attach(ns, &ns->base.profiles, name);
+               if (!new_profile)
+                       goto cleanup;
+               /*
+                * NOTE: Domain transitions from unconfined are allowed
+                * even when no_new_privs is set because this aways results
+                * in a further reduction of permissions.
+                */
+               goto apply;
+       }
+
+       /* find exec permissions for name */
+       state = aa_str_perms(profile->file.dfa, state, name, &cond, &perms);
+       if (cxt->onexec) {
+               struct file_perms cp;
+               info = "change_profile onexec";
+               if (!(perms.allow & AA_MAY_ONEXEC))
+                       goto audit;
+
+               /* test if this exec can be paired with change_profile onexec.
+                * onexec permission is linked to exec with a standard pairing
+                * exec\0change_profile
+                */
+               state = aa_dfa_null_transition(profile->file.dfa, state);
+               cp = change_profile_perms(profile, cxt->onexec->ns,
+                                         cxt->onexec->base.name,
+                                         AA_MAY_ONEXEC, state);
+
+               if (!(cp.allow & AA_MAY_ONEXEC))
+                       goto audit;
+               new_profile = aa_get_newest_profile(cxt->onexec);
+               goto apply;
+       }
+
+       if (perms.allow & MAY_EXEC) {
+               /* exec permission determine how to transition */
+               new_profile = x_to_profile(profile, name, perms.xindex);
+               if (!new_profile) {
+                       if (perms.xindex & AA_X_INHERIT) {
+                               /* (p|c|n)ix - don't change profile but do
+                                * use the newest version, which was picked
+                                * up above when getting profile
+                                */
+                               info = "ix fallback";
+                               new_profile = aa_get_profile(profile);
+                               goto x_clear;
+                       } else if (perms.xindex & AA_X_UNCONFINED) {
+                               new_profile = aa_get_newest_profile(ns->unconfined);
+                               info = "ux fallback";
+                       } else {
+                               error = -ENOENT;
+                               info = "profile not found";
+                               /* remove MAY_EXEC to audit as failure */
+                               perms.allow &= ~MAY_EXEC;
+                       }
+               }
+       } else if (COMPLAIN_MODE(profile)) {
+               /* no exec permission - are we in learning mode */
+               new_profile = aa_new_null_profile(profile, 0);
+               if (!new_profile) {
+                       error = -ENOMEM;
+                       info = "could not create null profile";
+               } else {
+                       error = -EACCES;
+                       target = new_profile->base.hname;
+               }
+               perms.xindex |= AA_X_UNSAFE;
+       } else
+               /* fail exec */
+               error = -EACCES;
+
+       /*
+        * Policy has specified a domain transition, if no_new_privs then
+        * fail the exec.
+        */
+       if (bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS) {
+               aa_put_profile(new_profile);
+               error = -EPERM;
+               goto cleanup;
+       }
+
+       if (!new_profile)
+               goto audit;
+
+       if (bprm->unsafe & LSM_UNSAFE_SHARE) {
+               /* FIXME: currently don't mediate shared state */
+               ;
+       }
+
+       if (bprm->unsafe & (LSM_UNSAFE_PTRACE | LSM_UNSAFE_PTRACE_CAP)) {
+               error = may_change_ptraced_domain(new_profile);
+               if (error) {
+                       aa_put_profile(new_profile);
+                       goto audit;
+               }
+       }
+
+       /* Determine if secure exec is needed.
+        * Can be at this point for the following reasons:
+        * 1. unconfined switching to confined
+        * 2. confined switching to different confinement
+        * 3. confined switching to unconfined
+        *
+        * Cases 2 and 3 are marked as requiring secure exec
+        * (unless policy specified "unsafe exec")
+        *
+        * bprm->unsafe is used to cache the AA_X_UNSAFE permission
+        * to avoid having to recompute in secureexec
+        */
+       if (!(perms.xindex & AA_X_UNSAFE)) {
+               AA_DEBUG("scrubbing environment variables for %s profile=%s\n",
+                        name, new_profile->base.hname);
+               bprm->unsafe |= AA_SECURE_X_NEEDED;
+       }
+apply:
+       target = new_profile->base.hname;
+       /* when transitioning profiles clear unsafe personality bits */
+       bprm->per_clear |= PER_CLEAR_ON_SETID;
+
+x_clear:
+       aa_put_profile(cxt->profile);
+       /* transfer new profile reference will be released when cxt is freed */
+       cxt->profile = new_profile;
+
+       /* clear out all temporary/transitional state from the context */
+       aa_clear_task_cxt_trans(cxt);
+
+audit:
+       error = aa_audit_file(profile, &perms, GFP_KERNEL, OP_EXEC, MAY_EXEC,
+                             name, target, cond.uid, info, error);
+
+cleanup:
+       aa_put_profile(profile);
+       kfree(buffer);
+
+       return error;
+}
+
+/**
+ * apparmor_bprm_secureexec - determine if secureexec is needed
+ * @bprm: binprm for exec  (NOT NULL)
+ *
+ * Returns: %1 if secureexec is needed else %0
+ */
+int apparmor_bprm_secureexec(struct linux_binprm *bprm)
+{
+       int ret = cap_bprm_secureexec(bprm);
+
+       /* the decision to use secure exec is computed in set_creds
+        * and stored in bprm->unsafe.
+        */
+       if (!ret && (bprm->unsafe & AA_SECURE_X_NEEDED))
+               ret = 1;
+
+       return ret;
+}
+
+/**
+ * apparmor_bprm_committing_creds - do task cleanup on committing new creds
+ * @bprm: binprm for the exec  (NOT NULL)
+ */
+void apparmor_bprm_committing_creds(struct linux_binprm *bprm)
+{
+       struct aa_profile *profile = __aa_current_profile();
+       struct aa_task_cxt *new_cxt = cred_cxt(bprm->cred);
+
+       /* bail out if unconfined or not changing profile */
+       if ((new_cxt->profile == profile) ||
+           (unconfined(new_cxt->profile)))
+               return;
+
+       current->pdeath_signal = 0;
+
+       /* reset soft limits and set hard limits for the new profile */
+       __aa_transition_rlimits(profile, new_cxt->profile);
+}
+
+/**
+ * apparmor_bprm_commited_cred - do cleanup after new creds committed
+ * @bprm: binprm for the exec  (NOT NULL)
+ */
+void apparmor_bprm_committed_creds(struct linux_binprm *bprm)
+{
+       /* TODO: cleanup signals - ipc mediation */
+       return;
+}
+
+/*
+ * Functions for self directed profile change
+ */
+
+/**
+ * new_compound_name - create an hname with @n2 appended to @n1
+ * @n1: base of hname  (NOT NULL)
+ * @n2: name to append (NOT NULL)
+ *
+ * Returns: new name or NULL on error
+ */
+static char *new_compound_name(const char *n1, const char *n2)
+{
+       char *name = kmalloc(strlen(n1) + strlen(n2) + 3, GFP_KERNEL);
+       if (name)
+               sprintf(name, "%s//%s", n1, n2);
+       return name;
+}
+
+/**
+ * aa_change_hat - change hat to/from subprofile
+ * @hats: vector of hat names to try changing into (MAYBE NULL if @count == 0)
+ * @count: number of hat names in @hats
+ * @token: magic value to validate the hat change
+ * @permtest: true if this is just a permission test
+ *
+ * Change to the first profile specified in @hats that exists, and store
+ * the @hat_magic in the current task context.  If the count == 0 and the
+ * @token matches that stored in the current task context, return to the
+ * top level profile.
+ *
+ * Returns %0 on success, error otherwise.
+ */
+int aa_change_hat(const char *hats[], int count, u64 token, bool permtest)
+{
+       const struct cred *cred;
+       struct aa_task_cxt *cxt;
+       struct aa_profile *profile, *previous_profile, *hat = NULL;
+       char *name = NULL;
+       int i;
+       struct file_perms perms = {};
+       const char *target = NULL, *info = NULL;
+       int error = 0;
+
+       /*
+        * Fail explicitly requested domain transitions if no_new_privs.
+        * There is no exception for unconfined as change_hat is not
+        * available.
+        */
+       if (task_no_new_privs(current))
+               return -EPERM;
+
+       /* released below */
+       cred = get_current_cred();
+       cxt = cred_cxt(cred);
+       profile = aa_cred_profile(cred);
+       previous_profile = cxt->previous;
+
+       if (unconfined(profile)) {
+               info = "unconfined";
+               error = -EPERM;
+               goto audit;
+       }
+
+       if (count) {
+               /* attempting to change into a new hat or switch to a sibling */
+               struct aa_profile *root;
+               if (PROFILE_IS_HAT(profile))
+                       root = aa_get_profile_rcu(&profile->parent);
+               else
+                       root = aa_get_profile(profile);
+
+               /* find first matching hat */
+               for (i = 0; i < count && !hat; i++)
+                       /* released below */
+                       hat = aa_find_child(root, hats[i]);
+               if (!hat) {
+                       if (!COMPLAIN_MODE(root) || permtest) {
+                               if (list_empty(&root->base.profiles))
+                                       error = -ECHILD;
+                               else
+                                       error = -ENOENT;
+                               aa_put_profile(root);
+                               goto out;
+                       }
+
+                       /*
+                        * In complain mode and failed to match any hats.
+                        * Audit the failure is based off of the first hat
+                        * supplied.  This is done due how userspace
+                        * interacts with change_hat.
+                        *
+                        * TODO: Add logging of all failed hats
+                        */
+
+                       /* freed below */
+                       name = new_compound_name(root->base.hname, hats[0]);
+                       aa_put_profile(root);
+                       target = name;
+                       /* released below */
+                       hat = aa_new_null_profile(profile, 1);
+                       if (!hat) {
+                               info = "failed null profile create";
+                               error = -ENOMEM;
+                               goto audit;
+                       }
+               } else {
+                       aa_put_profile(root);
+                       target = hat->base.hname;
+                       if (!PROFILE_IS_HAT(hat)) {
+                               info = "target not hat";
+                               error = -EPERM;
+                               goto audit;
+                       }
+               }
+
+               error = may_change_ptraced_domain(hat);
+               if (error) {
+                       info = "ptraced";
+                       error = -EPERM;
+                       goto audit;
+               }
+
+               if (!permtest) {
+                       error = aa_set_current_hat(hat, token);
+                       if (error == -EACCES)
+                               /* kill task in case of brute force attacks */
+                               perms.kill = AA_MAY_CHANGEHAT;
+                       else if (name && !error)
+                               /* reset error for learning of new hats */
+                               error = -ENOENT;
+               }
+       } else if (previous_profile) {
+               /* Return to saved profile.  Kill task if restore fails
+                * to avoid brute force attacks
+                */
+               target = previous_profile->base.hname;
+               error = aa_restore_previous_profile(token);
+               perms.kill = AA_MAY_CHANGEHAT;
+       } else
+               /* ignore restores when there is no saved profile */
+               goto out;
+
+audit:
+       if (!permtest)
+               error = aa_audit_file(profile, &perms, GFP_KERNEL,
+                                     OP_CHANGE_HAT, AA_MAY_CHANGEHAT, NULL,
+                                     target, GLOBAL_ROOT_UID, info, error);
+
+out:
+       aa_put_profile(hat);
+       kfree(name);
+       put_cred(cred);
+
+       return error;
+}
+
+/**
+ * aa_change_profile - perform a one-way profile transition
+ * @ns_name: name of the profile namespace to change to (MAYBE NULL)
+ * @hname: name of profile to change to (MAYBE NULL)
+ * @onexec: whether this transition is to take place immediately or at exec
+ * @permtest: true if this is just a permission test
+ *
+ * Change to new profile @name.  Unlike with hats, there is no way
+ * to change back.  If @name isn't specified the current profile name is
+ * used.
+ * If @onexec then the transition is delayed until
+ * the next exec.
+ *
+ * Returns %0 on success, error otherwise.
+ */
+int aa_change_profile(const char *ns_name, const char *hname, bool onexec,
+                     bool permtest)
+{
+       const struct cred *cred;
+       struct aa_profile *profile, *target = NULL;
+       struct aa_namespace *ns = NULL;
+       struct file_perms perms = {};
+       const char *name = NULL, *info = NULL;
+       int op, error = 0;
+       u32 request;
+
+       if (!hname && !ns_name)
+               return -EINVAL;
+
+       if (onexec) {
+               request = AA_MAY_ONEXEC;
+               op = OP_CHANGE_ONEXEC;
+       } else {
+               request = AA_MAY_CHANGE_PROFILE;
+               op = OP_CHANGE_PROFILE;
+       }
+
+       cred = get_current_cred();
+       profile = aa_cred_profile(cred);
+
+       /*
+        * Fail explicitly requested domain transitions if no_new_privs
+        * and not unconfined.
+        * Domain transitions from unconfined are allowed even when
+        * no_new_privs is set because this aways results in a reduction
+        * of permissions.
+        */
+       if (task_no_new_privs(current) && !unconfined(profile)) {
+               put_cred(cred);
+               return -EPERM;
+       }
+
+       if (ns_name) {
+               /* released below */
+               ns = aa_find_namespace(profile->ns, ns_name);
+               if (!ns) {
+                       /* we don't create new namespace in complain mode */
+                       name = ns_name;
+                       info = "namespace not found";
+                       error = -ENOENT;
+                       goto audit;
+               }
+       } else
+               /* released below */
+               ns = aa_get_namespace(profile->ns);
+
+       /* if the name was not specified, use the name of the current profile */
+       if (!hname) {
+               if (unconfined(profile))
+                       hname = ns->unconfined->base.hname;
+               else
+                       hname = profile->base.hname;
+       }
+
+       perms = change_profile_perms(profile, ns, hname, request,
+                                    profile->file.start);
+       if (!(perms.allow & request)) {
+               error = -EACCES;
+               goto audit;
+       }
+
+       /* released below */
+       target = aa_lookup_profile(ns, hname);
+       if (!target) {
+               info = "profile not found";
+               error = -ENOENT;
+               if (permtest || !COMPLAIN_MODE(profile))
+                       goto audit;
+               /* released below */
+               target = aa_new_null_profile(profile, 0);
+               if (!target) {
+                       info = "failed null profile create";
+                       error = -ENOMEM;
+                       goto audit;
+               }
+       }
+
+       /* check if tracing task is allowed to trace target domain */
+       error = may_change_ptraced_domain(target);
+       if (error) {
+               info = "ptrace prevents transition";
+               goto audit;
+       }
+
+       if (permtest)
+               goto audit;
+
+       if (onexec)
+               error = aa_set_current_onexec(target);
+       else
+               error = aa_replace_current_profile(target);
+
+audit:
+       if (!permtest)
+               error = aa_audit_file(profile, &perms, GFP_KERNEL, op, request,
+                                     name, hname, GLOBAL_ROOT_UID, info, error);
+
+       aa_put_namespace(ns);
+       aa_put_profile(target);
+       put_cred(cred);
+
+       return error;
+}