Re: [PATCH] btrfs: avoid null pointer dereference on fs_info when calling btrfs_crit

[David Sterba]

On Mon, Sep 11, 2017 at 04:15:28PM +0100, Colin King wrote:
> From: Colin Ian King <colin.king@xxxxxxxxxxxxx>
> 
> 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@xxxxxxxxxxxxx>

Reviewed-by: David Sterba <dsterba@xxxxxxxx>