Re: [RESEND PATCH] btrfs: Handle uninitialised inode eviction

[David Sterba <dsterba@suse.cz>]

On Mon, Jul 11, 2016 at 09:43:09AM +0300, Nikolay Borisov wrote:
> The code flow in btrfs_new_inode allows for btrfs_evict_inode to be
> called with not fully initialised inode (e.g. ->root member not
> being set). This can happen when btrfs_set_inode_index in
> btrfs_new_inode fails, which in turn would call iput for the newly
> allocated inode. This in turn leads to vfs calling into btrfs_evict_inode.
> This leads to null pointer dereference. To handle this situation check whether
> the passed inode has root set and just free it in case it doesn't.
> 
> Signed-off-by: Nikolay Borisov <kernel@kyup.com>
> Reviewed-by: Josef Bacik <jbacik@fb.com>
> ---
>  fs/btrfs/inode.c | 9 ++++++++-
>  1 file changed, 8 insertions(+), 1 deletion(-)
> 
> Hello, 
> 
> I belive this is fixes the issue reported in 
> http://thread.gmane.org/gmane.comp.file-systems.btrfs/57809

There's some time left before 4.7 release, so I'll send another pull
request, including this patch.