From: Rickard Strandqvist <rickard_strandqvist@spectrumdigital.se>
Date: Thu, 22 May 2014 20:43:43 +0000 (+0200)
Subject: fs: btrfs: volumes.c: Fix for possible null pointer dereference
X-Git-Tag: v3.14.10~12
X-Git-Url: https://git.fsl.cs.sunysb.edu/?a=commitdiff_plain;h=3379d704fb52e2e989fb3c6f0bdf1d5e74387cb1;p=unionfs-3.16.y.git

fs: btrfs: volumes.c: Fix for possible null pointer dereference

commit 8321cf2596d283821acc466377c2b85bcd3422b7 upstream.

There is otherwise a risk of a possible null pointer dereference.

Was largely found by using a static code analysis program called cppcheck.

Signed-off-by: Rickard Strandqvist <rickard_strandqvist@spectrumdigital.se>
Signed-off-by: Chris Mason <clm@fb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 4e42358bd162..e46d3d72a9c9 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -1676,11 +1676,12 @@ int btrfs_rm_device(struct btrfs_root *root, char *device_path)
 		struct btrfs_fs_devices *fs_devices;
 		fs_devices = root->fs_info->fs_devices;
 		while (fs_devices) {
-			if (fs_devices->seed == cur_devices)
+			if (fs_devices->seed == cur_devices) {
+				fs_devices->seed = cur_devices->seed;
 				break;
+			}
 			fs_devices = fs_devices->seed;
 		}
-		fs_devices->seed = cur_devices->seed;
 		cur_devices->seed = NULL;
 		lock_chunks(root);
 		__btrfs_close_devices(cur_devices);