Initial import

1 files changed, 854 insertions, 0 deletions

diff --git a/security/apparmor/domain.c b/security/apparmor/domain.c
new file mode 100644
index 000000000..d97cba3e3
--- /dev/null
+++ b/security/apparmor/domain.c
@@ -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;
+}