From: Liu Bo <bo.li.liu@oracle.com>
Date: Thu, 11 Jun 2015 06:16:44 +0000 (+0800)
Subject: Btrfs: fix use-after-free in btrfs_replay_log
X-Git-Tag: v4.2-rc1~65^2~3
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=0eeff2362b829b5e80f8b69f86b60b8094bc742d;p=karo-tx-linux.git

Btrfs: fix use-after-free in btrfs_replay_log

@log_root_tree should not be referenced after kfree.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Reported-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Chris Mason <clm@fb.com>
---

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 695363ae1c28..b7fa3bac2cff 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -2321,8 +2321,9 @@ static int btrfs_replay_log(struct btrfs_fs_info *fs_info,
 			fs_info->generation + 1);
 	if (IS_ERR(log_tree_root->node)) {
 		printk(KERN_ERR "BTRFS: failed to read log tree\n");
+		ret = PTR_ERR(log_tree_root->node);
 		kfree(log_tree_root);
-		return PTR_ERR(log_tree_root->node);
+		return ret;
 	} else if (!extent_buffer_uptodate(log_tree_root->node)) {
 		printk(KERN_ERR "BTRFS: failed to read log tree\n");
 		free_extent_buffer(log_tree_root->node);