Re: [PATCH] 9p: fix NULL pointer dereferences

From: Tomas Bortoli
Date: Thu Jul 26 2018 - 10:14:07 EST

On 07/26/2018 11:48 AM, Dominique Martinet wrote:
> Dmitry Vyukov wrote on Thu, Jul 26, 2018:
>>> Let's refuse that at much higher level, like v9fs_mount() in
>>> fs/9p/vfs_super.c
>>> I can't think of any valid reason for dev_name to be NULL, it's the
>>> target IP or virtio handle.
>> But I think trans=fd allows NULL addr today, no?

How ?

> Ah, right, I read the patch too fast and read unix_create as fd_create,
> I never realized there was a unix_create variant...
> fd legitimately doesn't need a name, you are correct.
> I'm really curious if anyone ever uses the unix/fd variants for "real"
> stuff though! (not meaning syzbot isn't real, but I have yet to see
> anything take advantage of this, even if I could imagine some fun
> applications by piping the wmii libixp server socket.. and just crashed
> my laptop trying because of the (fixed) trans put bug.. I have yet to
> see anyone actually doing this)
> On the other hand, virtio, rdma and xen all have the same problem, so
> Thomas, please fix them instead :)

So just by patching v9fs_mount ?