btrfs: avoid null pointer dereference on fs_info when calling btrfs_crit
commit3993b112dac968612b0b213ed59cb30f50b0015b
authorColin Ian King <colin.king@canonical.com>
Mon, 11 Sep 2017 15:15:28 +0000 (11 16:15 +0100)
committerDavid Sterba <dsterba@suse.com>
Mon, 30 Oct 2017 11:27:56 +0000 (30 12:27 +0100)
tree6c686b1a0fb68a9ae28512e893d882b77b1615c4
parentfa0d0888bda13bc96d99024cba40ae3a135de385
btrfs: avoid null pointer dereference on fs_info when calling btrfs_crit

There are checks on fs_info in __btrfs_panic to avoid dereferencing a
null fs_info, however, there is a call to btrfs_crit that may also
dereference a null fs_info. Fix this by adding a check to see if fs_info
is null and only print the s_id if fs_info is non-null.

Detected by CoverityScan CID#401973 ("Dereference after null check")

Fixes: efe120a067c8 ("Btrfs: convert printk to btrfs_ and fix BTRFS prefix")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
fs/btrfs/super.c