1 files changed, 32 insertions, 9 deletions

diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c
index af683734bbdd..13b8f68f6c24 100644
--- a/fs/ubifs/super.c
+++ b/fs/ubifs/super.c
@@ -566,6 +566,8 @@ static int init_constants_early(struct ubifs_info *c)
 	c->ranges[UBIFS_AUTH_NODE].min_len = UBIFS_AUTH_NODE_SZ;
 	c->ranges[UBIFS_AUTH_NODE].max_len = UBIFS_AUTH_NODE_SZ +
 				UBIFS_MAX_HMAC_LEN;
+	c->ranges[UBIFS_SIG_NODE].min_len = UBIFS_SIG_NODE_SZ;
+	c->ranges[UBIFS_SIG_NODE].max_len = c->leb_size - UBIFS_SB_NODE_SZ;
 
 	c->ranges[UBIFS_INO_NODE].min_len  = UBIFS_INO_NODE_SZ;
 	c->ranges[UBIFS_INO_NODE].max_len  = UBIFS_MAX_INO_NODE_SZ;
@@ -1359,6 +1361,26 @@ static int mount_ubifs(struct ubifs_info *c)
 			goto out_lpt;
 	}
 
+	/*
+	 * Handle offline signed images: Now that the master node is
+	 * written and its validation no longer depends on the hash
+	 * in the superblock, we can update the offline signed
+	 * superblock with a HMAC version,
+	 */
+	if (ubifs_authenticated(c) && ubifs_hmac_zero(c, c->sup_node->hmac)) {
+		err = ubifs_hmac_wkm(c, c->sup_node->hmac_wkm);
+		if (err)
+			goto out_lpt;
+		c->superblock_need_write = 1;
+	}
+
+	if (!c->ro_mount && c->superblock_need_write) {
+		err = ubifs_write_sb_node(c, c->sup_node);
+		if (err)
+			goto out_lpt;
+		c->superblock_need_write = 0;
+	}
+
 	err = dbg_check_idx_size(c, c->bi.old_idx_sz);
 	if (err)
 		goto out_lpt;
@@ -1643,15 +1665,6 @@ static int ubifs_remount_rw(struct ubifs_info *c)
 	if (err)
 		goto out;
 
-	if (c->old_leb_cnt != c->leb_cnt) {
-		struct ubifs_sb_node *sup = c->sup_node;
-
-		sup->leb_cnt = cpu_to_le32(c->leb_cnt);
-		err = ubifs_write_sb_node(c, sup);
-		if (err)
-			goto out;
-	}
-
 	if (c->need_recovery) {
 		ubifs_msg(c, "completing deferred recovery");
 		err = ubifs_write_rcvrd_mst_node(c);
@@ -1683,6 +1696,16 @@ static int ubifs_remount_rw(struct ubifs_info *c)
 			goto out;
 	}
 
+	if (c->superblock_need_write) {
+		struct ubifs_sb_node *sup = c->sup_node;
+
+		err = ubifs_write_sb_node(c, sup);
+		if (err)
+			goto out;
+
+		c->superblock_need_write = 0;
+	}
+
 	c->ileb_buf = vmalloc(c->leb_size);
 	if (!c->ileb_buf) {
 		err = -ENOMEM;