Merge tag 'apparmor-pr-2019-12-03' of git://git.kernel.org/pub/scm/linux/kernel/git/jj/linux-apparmor

Pull apparmor updates from John Johansen:
 "Features:

   - increase left match history buffer size to provide improved
     conflict resolution in overlapping execution rules.

   - switch buffer allocation to use a memory pool and GFP_KERNEL where
     possible.

   - add compression of policy blobs to reduce memory usage.

  Cleanups:

   - fix spelling mistake "immutible" -> "immutable"

  Bug fixes:

   - fix unsigned len comparison in update_for_len macro

   - fix sparse warning for type-casting of current->real_cred"

* tag 'apparmor-pr-2019-12-03' of git://git.kernel.org/pub/scm/linux/kernel/git/jj/linux-apparmor:
  apparmor: make it so work buffers can be allocated from atomic context
  apparmor: reduce rcu_read_lock scope for aa_file_perm mediation
  apparmor: fix wrong buffer allocation in aa_new_mount
  apparmor: fix unsigned len comparison with less than zero
  apparmor: increase left match history buffer size
  apparmor: Switch to GFP_KERNEL where possible
  apparmor: Use a memory pool instead per-CPU caches
  apparmor: Force type-casting of current->real_cred
  apparmor: fix spelling mistake "immutible" -> "immutable"
  apparmor: fix blob compression when ns is forced on a policy load
  apparmor: fix missing ZLIB defines
  apparmor: fix blob compression build failure on ppc
  apparmor: Initial implementation of raw policy blob compression

security/apparmor/file.c

@@ -76,7 +76,7 @@ static void file_audit_cb(struct audit_buffer *ab, void *va)
 	if (aad(sa)->peer) {
 		audit_log_format(ab, " target=");
 		aa_label_xaudit(ab, labels_ns(aad(sa)->label), aad(sa)->peer,
-				FLAG_VIEW_SUBNS, GFP_ATOMIC);
+				FLAG_VIEW_SUBNS, GFP_KERNEL);
 	} else if (aad(sa)->fs.target) {
 		audit_log_format(ab, " target=");
 		audit_log_untrustedstring(ab, aad(sa)->fs.target);
@@ -332,12 +332,14 @@ int aa_path_perm(const char *op, struct aa_label *label,
 
 	flags |= PATH_DELEGATE_DELETED | (S_ISDIR(cond->mode) ? PATH_IS_DIR :
 								0);
-	get_buffers(buffer);
+	buffer = aa_get_buffer(false);
+	if (!buffer)
+		return -ENOMEM;
 	error = fn_for_each_confined(label, profile,
 			profile_path_perm(op, profile, path, buffer, request,
 					  cond, flags, &perms));
 
-	put_buffers(buffer);
+	aa_put_buffer(buffer);
 
 	return error;
 }
@@ -475,12 +477,18 @@ int aa_path_link(struct aa_label *label, struct dentry *old_dentry,
 	int error;
 
 	/* buffer freed below, lname is pointer in buffer */
-	get_buffers(buffer, buffer2);
+	buffer = aa_get_buffer(false);
+	buffer2 = aa_get_buffer(false);
+	error = -ENOMEM;
+	if (!buffer || !buffer2)
+		goto out;
+
 	error = fn_for_each_confined(label, profile,
 			profile_path_link(profile, &link, buffer, &target,
 					  buffer2, &cond));
-	put_buffers(buffer, buffer2);
-
+out:
+	aa_put_buffer(buffer);
+	aa_put_buffer(buffer2);
 	return error;
 }
 
@@ -507,7 +515,7 @@ static void update_file_ctx(struct aa_file_ctx *fctx, struct aa_label *label,
 
 static int __file_path_perm(const char *op, struct aa_label *label,
 			    struct aa_label *flabel, struct file *file,
-			    u32 request, u32 denied)
+			    u32 request, u32 denied, bool in_atomic)
 {
 	struct aa_profile *profile;
 	struct aa_perms perms = {};
@@ -524,7 +532,9 @@ static int __file_path_perm(const char *op, struct aa_label *label,
 		return 0;
 
 	flags = PATH_DELEGATE_DELETED | (S_ISDIR(cond.mode) ? PATH_IS_DIR : 0);
-	get_buffers(buffer);
+	buffer = aa_get_buffer(in_atomic);
+	if (!buffer)
+		return -ENOMEM;
 
 	/* check every profile in task label not in current cache */
 	error = fn_for_each_not_in_set(flabel, label, profile,
@@ -553,7 +563,7 @@ static int __file_path_perm(const char *op, struct aa_label *label,
 	if (!error)
 		update_file_ctx(file_ctx(file), label, request);
 
-	put_buffers(buffer);
+	aa_put_buffer(buffer);
 
 	return error;
 }
@@ -590,11 +600,12 @@ static int __file_sock_perm(const char *op, struct aa_label *label,
  * @label: label being enforced   (NOT NULL)
  * @file: file to revalidate access permissions on  (NOT NULL)
  * @request: requested permissions
+ * @in_atomic: whether allocations need to be done in atomic context
  *
  * Returns: %0 if access allowed else error
  */
 int aa_file_perm(const char *op, struct aa_label *label, struct file *file,
-		 u32 request)
+		 u32 request, bool in_atomic)
 {
 	struct aa_file_ctx *fctx;
 	struct aa_label *flabel;
@@ -607,7 +618,8 @@ int aa_file_perm(const char *op, struct aa_label *label, struct file *file,
 	fctx = file_ctx(file);
 
 	rcu_read_lock();
-	flabel  = rcu_dereference(fctx->label);
+	flabel  = aa_get_newest_label(rcu_dereference(fctx->label));
+	rcu_read_unlock();
 	AA_BUG(!flabel);
 
 	/* revalidate access, if task is unconfined, or the cached cred
@@ -626,14 +638,13 @@ int aa_file_perm(const char *op, struct aa_label *label, struct file *file,
 
 	if (file->f_path.mnt && path_mediated_fs(file->f_path.dentry))
 		error = __file_path_perm(op, label, flabel, file, request,
-					 denied);
+					 denied, in_atomic);
 
 	else if (S_ISSOCK(file_inode(file)->i_mode))
 		error = __file_sock_perm(op, label, flabel, file, request,
 					 denied);
 done:
-	rcu_read_unlock();
-
+	aa_put_label(flabel);
 	return error;
 }
 
@@ -655,7 +666,8 @@ static void revalidate_tty(struct aa_label *label)
 					     struct tty_file_private, list);
 		file = file_priv->file;
 
-		if (aa_file_perm(OP_INHERIT, label, file, MAY_READ | MAY_WRITE))
+		if (aa_file_perm(OP_INHERIT, label, file, MAY_READ | MAY_WRITE,
+				 IN_ATOMIC))
 			drop_tty = 1;
 	}
 	spin_unlock(&tty->files_lock);
@@ -669,7 +681,8 @@ static int match_file(const void *p, struct file *file, unsigned int fd)
 {
 	struct aa_label *label = (struct aa_label *)p;
 
-	if (aa_file_perm(OP_INHERIT, label, file, aa_map_file_to_perms(file)))
+	if (aa_file_perm(OP_INHERIT, label, file, aa_map_file_to_perms(file),
+			 IN_ATOMIC))
 		return fd + 1;
 	return 0;
 }