[PATCH 08/21] btrfs: add check to sysfs handler of label

David Sterba
2016-06-03T15:43:04Z

commit 66ac9fe7bacf9fa76c472efc7a7aaa590c7bce6a upstream.

Add a sanity check for the fs_info as we will dereference it, similar to
what the 'store features' handler does.

Signed-off-by: David Sterba <dsterba@suse.com>
---
fs/btrfs/sysfs.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c
index 6a6bb600b1ff..3d14618ce54b 100644
--- a/fs/btrfs/sysfs.c
+++ b/fs/btrfs/sysfs.c
@@ -377,6 +377,9 @@ static ssize_t btrfs_label_store(struct kobject *kobj,
struct btrfs_fs_info *fs_info = to_fs_info(kobj);
size_t p_len;

+ if (!fs_info)
+ return -EPERM;
+
if (fs_info->sb->s_flags & MS_RDONLY)
return -EROFS;

--
2.7.1