1 files changed, 32 insertions, 41 deletions

diff --git a/fs/ubifs/sb.c b/fs/ubifs/sb.c
index 3da90c951c23..a551eb3e9b89 100644
--- a/fs/ubifs/sb.c
+++ b/fs/ubifs/sb.c
@@ -1,21 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * This file is part of UBIFS.
  *
  * Copyright (C) 2006-2008 Nokia Corporation.
  *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License version 2 as published by
- * the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
- * more details.
- *
- * You should have received a copy of the GNU General Public License along with
- * this program; if not, write to the Free Software Foundation, Inc., 51
- * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
- *
  * Authors: Artem Bityutskiy (Битюцкий Артём)
  *          Adrian Hunter
  */
@@ -590,17 +578,26 @@ static int authenticate_sb_node(struct ubifs_info *c,
 		return -EINVAL;
 	}
 
-	err = ubifs_hmac_wkm(c, hmac_wkm);
-	if (err)
-		return err;
-
-	if (ubifs_check_hmac(c, hmac_wkm, sup->hmac_wkm)) {
-		ubifs_err(c, "provided key does not fit");
-		return -ENOKEY;
+	/*
+	 * The super block node can either be authenticated by a HMAC or
+	 * by a signature in a ubifs_sig_node directly following the
+	 * super block node to support offline image creation.
+	 */
+	if (ubifs_hmac_zero(c, sup->hmac)) {
+		err = ubifs_sb_verify_signature(c, sup);
+	} else {
+		err = ubifs_hmac_wkm(c, hmac_wkm);
+		if (err)
+			return err;
+		if (ubifs_check_hmac(c, hmac_wkm, sup->hmac_wkm)) {
+			ubifs_err(c, "provided key does not fit");
+			return -ENOKEY;
+		}
+		err = ubifs_node_verify_hmac(c, sup, sizeof(*sup),
+					     offsetof(struct ubifs_sb_node,
+						      hmac));
 	}
 
-	err = ubifs_node_verify_hmac(c, sup, sizeof(*sup),
-				     offsetof(struct ubifs_sb_node, hmac));
 	if (err)
 		ubifs_err(c, "Failed to authenticate superblock: %d", err);
 
@@ -748,31 +745,24 @@ int ubifs_read_superblock(struct ubifs_info *c)
 		goto out;
 	}
 
-#ifndef CONFIG_UBIFS_FS_ENCRYPTION
-	if (c->encrypted) {
+	if (!IS_ENABLED(CONFIG_FS_ENCRYPTION) && c->encrypted) {
 		ubifs_err(c, "file system contains encrypted files but UBIFS"
 			     " was built without crypto support.");
 		err = -EINVAL;
 		goto out;
 	}
-#endif
 
 	/* Automatically increase file system size to the maximum size */
-	c->old_leb_cnt = c->leb_cnt;
 	if (c->leb_cnt < c->vi.size && c->leb_cnt < c->max_leb_cnt) {
+		int old_leb_cnt = c->leb_cnt;
+
 		c->leb_cnt = min_t(int, c->max_leb_cnt, c->vi.size);
-		if (c->ro_mount)
-			dbg_mnt("Auto resizing (ro) from %d LEBs to %d LEBs",
-				c->old_leb_cnt,	c->leb_cnt);
-		else {
-			dbg_mnt("Auto resizing (sb) from %d LEBs to %d LEBs",
-				c->old_leb_cnt, c->leb_cnt);
-			sup->leb_cnt = cpu_to_le32(c->leb_cnt);
-			err = ubifs_write_sb_node(c, sup);
-			if (err)
-				goto out;
-			c->old_leb_cnt = c->leb_cnt;
-		}
+		sup->leb_cnt = cpu_to_le32(c->leb_cnt);
+
+		c->superblock_need_write = 1;
+
+		dbg_mnt("Auto resizing from %d LEBs to %d LEBs",
+			old_leb_cnt, c->leb_cnt);
 	}
 
 	c->log_bytes = (long long)c->log_lebs * c->leb_size;
@@ -930,9 +920,7 @@ int ubifs_fixup_free_space(struct ubifs_info *c)
 	c->space_fixup = 0;
 	sup->flags &= cpu_to_le32(~UBIFS_FLG_SPACE_FIXUP);
 
-	err = ubifs_write_sb_node(c, sup);
-	if (err)
-		return err;
+	c->superblock_need_write = 1;
 
 	ubifs_msg(c, "free space fixup complete");
 	return err;
@@ -943,6 +931,9 @@ int ubifs_enable_encryption(struct ubifs_info *c)
 	int err;
 	struct ubifs_sb_node *sup = c->sup_node;
 
+	if (!IS_ENABLED(CONFIG_FS_ENCRYPTION))
+		return -EOPNOTSUPP;
+
 	if (c->encrypted)
 		return 0;