1 files changed, 74 insertions, 43 deletions

diff --git a/security/apparmor/domain.c b/security/apparmor/domain.c
index c1e18ba5bdc..452567d3a08 100644
--- a/security/apparmor/domain.c
+++ b/security/apparmor/domain.c
@@ -50,40 +50,34 @@ void aa_free_domain_entries(struct aa_domain *domain)
 
 /**
  * may_change_ptraced_domain - check if can change profile on ptraced task
- * @task: task we want to change profile of   (NOT NULL)
  * @to_profile: profile to change to  (NOT NULL)
  *
- * Check if the task is ptraced and if so if the tracing task is allowed
+ * 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 task_struct *task,
-				     struct aa_profile *to_profile)
+static int may_change_ptraced_domain(struct aa_profile *to_profile)
 {
 	struct task_struct *tracer;
-	const struct cred *cred = NULL;
 	struct aa_profile *tracerp = NULL;
 	int error = 0;
 
 	rcu_read_lock();
-	tracer = ptrace_parent(task);
-	if (tracer) {
+	tracer = ptrace_parent(current);
+	if (tracer)
 		/* released below */
-		cred = get_task_cred(tracer);
-		tracerp = aa_cred_profile(cred);
-	}
+		tracerp = aa_get_task_profile(tracer);
 
 	/* not ptraced */
 	if (!tracer || unconfined(tracerp))
 		goto out;
 
-	error = aa_may_ptrace(tracer, tracerp, to_profile, PTRACE_MODE_ATTACH);
+	error = aa_may_ptrace(tracerp, to_profile, PTRACE_MODE_ATTACH);
 
 out:
 	rcu_read_unlock();
-	if (cred)
-		put_cred(cred);
+	aa_put_profile(tracerp);
 
 	return error;
 }
@@ -148,7 +142,7 @@ static struct aa_profile *__attach_match(const char *name,
 	int len = 0;
 	struct aa_profile *profile, *candidate = NULL;
 
-	list_for_each_entry(profile, head, base.list) {
+	list_for_each_entry_rcu(profile, head, base.list) {
 		if (profile->flags & PFLAG_NULL)
 			continue;
 		if (profile->xmatch && profile->xmatch_len > len) {
@@ -181,9 +175,9 @@ static struct aa_profile *find_attach(struct aa_namespace *ns,
 {
 	struct aa_profile *profile;
 
-	read_lock(&ns->lock);
+	rcu_read_lock();
 	profile = aa_get_profile(__attach_match(name, list));
-	read_unlock(&ns->lock);
+	rcu_read_unlock();
 
 	return profile;
 }
@@ -349,8 +343,8 @@ int apparmor_bprm_set_creds(struct linux_binprm *bprm)
 	unsigned int state;
 	struct file_perms perms = {};
 	struct path_cond cond = {
-		bprm->file->f_path.dentry->d_inode->i_uid,
-		bprm->file->f_path.dentry->d_inode->i_mode
+		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);
@@ -360,10 +354,10 @@ int apparmor_bprm_set_creds(struct linux_binprm *bprm)
 	if (bprm->cred_prepared)
 		return 0;
 
-	cxt = bprm->cred->security;
+	cxt = cred_cxt(bprm->cred);
 	BUG_ON(!cxt);
 
-	profile = aa_get_profile(aa_newest_version(cxt->profile));
+	profile = aa_get_newest_profile(cxt->profile);
 	/*
 	 * get the namespace from the replacement profile as replacement
 	 * can change the namespace
@@ -372,13 +366,12 @@ int apparmor_bprm_set_creds(struct linux_binprm *bprm)
 	state = profile->file.start;
 
 	/* buffer freed below, name is pointer into buffer */
-	error = aa_get_name(&bprm->file->f_path, profile->path_flags, &buffer,
-			    &name);
+	error = aa_path_name(&bprm->file->f_path, profile->path_flags, &buffer,
+			     &name, &info);
 	if (error) {
-		if (profile->flags &
-		    (PFLAG_IX_ON_NAME_ERROR | PFLAG_UNCONFINED))
+		if (unconfined(profile) ||
+		    (profile->flags & PFLAG_IX_ON_NAME_ERROR))
 			error = 0;
-		info = "Exec failed name resolution";
 		name = bprm->filename;
 		goto audit;
 	}
@@ -395,6 +388,11 @@ int apparmor_bprm_set_creds(struct linux_binprm *bprm)
 			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;
 	}
 
@@ -411,12 +409,13 @@ int apparmor_bprm_set_creds(struct linux_binprm *bprm)
 		 * exec\0change_profile
 		 */
 		state = aa_dfa_null_transition(profile->file.dfa, state);
-		cp = change_profile_perms(profile, cxt->onexec->ns, name,
+		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_profile(aa_newest_version(cxt->onexec));
+		new_profile = aa_get_newest_profile(cxt->onexec);
 		goto apply;
 	}
 
@@ -433,11 +432,13 @@ int apparmor_bprm_set_creds(struct linux_binprm *bprm)
 				new_profile = aa_get_profile(profile);
 				goto x_clear;
 			} else if (perms.xindex & AA_X_UNCONFINED) {
-				new_profile = aa_get_profile(ns->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)) {
@@ -455,6 +456,16 @@ int apparmor_bprm_set_creds(struct linux_binprm *bprm)
 		/* 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;
 
@@ -464,7 +475,7 @@ int apparmor_bprm_set_creds(struct linux_binprm *bprm)
 	}
 
 	if (bprm->unsafe & (LSM_UNSAFE_PTRACE | LSM_UNSAFE_PTRACE_CAP)) {
-		error = may_change_ptraced_domain(current, new_profile);
+		error = may_change_ptraced_domain(new_profile);
 		if (error) {
 			aa_put_profile(new_profile);
 			goto audit;
@@ -499,11 +510,7 @@ x_clear:
 	cxt->profile = new_profile;
 
 	/* clear out all temporary/transitional state from the context */
-	aa_put_profile(cxt->previous);
-	aa_put_profile(cxt->onexec);
-	cxt->previous = NULL;
-	cxt->onexec = NULL;
-	cxt->token = 0;
+	aa_clear_task_cxt_trans(cxt);
 
 audit:
 	error = aa_audit_file(profile, &perms, GFP_KERNEL, OP_EXEC, MAY_EXEC,
@@ -542,7 +549,7 @@ int apparmor_bprm_secureexec(struct linux_binprm *bprm)
 void apparmor_bprm_committing_creds(struct linux_binprm *bprm)
 {
 	struct aa_profile *profile = __aa_current_profile();
-	struct aa_task_cxt *new_cxt = bprm->cred->security;
+	struct aa_task_cxt *new_cxt = cred_cxt(bprm->cred);
 
 	/* bail out if unconfined or not changing profile */
 	if ((new_cxt->profile == profile) ||
@@ -609,9 +616,17 @@ int aa_change_hat(const char *hats[], int count, u64 token, bool permtest)
 	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 (current->no_new_privs)
+		return -EPERM;
+
 	/* released below */
 	cred = get_current_cred();
-	cxt = cred->security;
+	cxt = cred_cxt(cred);
 	profile = aa_cred_profile(cred);
 	previous_profile = cxt->previous;
 
@@ -624,7 +639,10 @@ int aa_change_hat(const char *hats[], int count, u64 token, bool permtest)
 	if (count) {
 		/* attempting to change into a new hat or switch to a sibling */
 		struct aa_profile *root;
-		root = PROFILE_IS_HAT(profile) ? profile->parent : profile;
+		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++)
@@ -636,6 +654,7 @@ int aa_change_hat(const char *hats[], int count, u64 token, bool permtest)
 					error = -ECHILD;
 				else
 					error = -ENOENT;
+				aa_put_profile(root);
 				goto out;
 			}
 
@@ -650,6 +669,7 @@ int aa_change_hat(const char *hats[], int count, u64 token, bool permtest)
 
 			/* 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);
@@ -659,6 +679,7 @@ int aa_change_hat(const char *hats[], int count, u64 token, bool permtest)
 				goto audit;
 			}
 		} else {
+			aa_put_profile(root);
 			target = hat->base.hname;
 			if (!PROFILE_IS_HAT(hat)) {
 				info = "target not hat";
@@ -667,7 +688,7 @@ int aa_change_hat(const char *hats[], int count, u64 token, bool permtest)
 			}
 		}
 
-		error = may_change_ptraced_domain(current, hat);
+		error = may_change_ptraced_domain(hat);
 		if (error) {
 			info = "ptraced";
 			error = -EPERM;
@@ -698,7 +719,7 @@ audit:
 	if (!permtest)
 		error = aa_audit_file(profile, &perms, GFP_KERNEL,
 				      OP_CHANGE_HAT, AA_MAY_CHANGEHAT, NULL,
-				      target, 0, info, error);
+				      target, GLOBAL_ROOT_UID, info, error);
 
 out:
 	aa_put_profile(hat);
@@ -727,7 +748,6 @@ int aa_change_profile(const char *ns_name, const char *hname, bool onexec,
 		      bool permtest)
 {
 	const struct cred *cred;
-	struct aa_task_cxt *cxt;
 	struct aa_profile *profile, *target = NULL;
 	struct aa_namespace *ns = NULL;
 	struct file_perms perms = {};
@@ -747,9 +767,20 @@ int aa_change_profile(const char *ns_name, const char *hname, bool onexec,
 	}
 
 	cred = get_current_cred();
-	cxt = cred->security;
 	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 (current->no_new_privs && !unconfined(profile)) {
+		put_cred(cred);
+		return -EPERM;
+	}
+
 	if (ns_name) {
 		/* released below */
 		ns = aa_find_namespace(profile->ns, ns_name);
@@ -796,7 +827,7 @@ int aa_change_profile(const char *ns_name, const char *hname, bool onexec,
 	}
 
 	/* check if tracing task is allowed to trace target domain */
-	error = may_change_ptraced_domain(current, target);
+	error = may_change_ptraced_domain(target);
 	if (error) {
 		info = "ptrace prevents transition";
 		goto audit;
@@ -813,7 +844,7 @@ int aa_change_profile(const char *ns_name, const char *hname, bool onexec,
 audit:
 	if (!permtest)
 		error = aa_audit_file(profile, &perms, GFP_KERNEL, op, request,
-				      name, hname, 0, info, error);
+				      name, hname, GLOBAL_ROOT_UID, info, error);
 
 	aa_put_namespace(ns);
 	aa_put_profile(target);