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From: David Howells <dhowells@redhat.com>
To: Farhad Alemi <farhad.alemi@berkeley.edu>
Cc: dhowells@redhat.com, Marc Dionne <marc.dionne@auristor.com>,
	falemi@asu.edu, linux-afs@lists.infradead.org,
	linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [BUG] afs: ERR_PTR dereference in afs_lookup_server() error path
Date: Wed, 02 Sep 2026 12:40:55 +0100	[thread overview]
Message-ID: <3266510.1788349255@warthog.procyon.org.uk> (raw)
In-Reply-To: <CA+0ovChcGF2nsf0iJNGXM79iGv2fKEqYi4DGQ55aygBcKg2NGQ@mail.gmail.com>

Hi Farhad,

> While fuzzing Linux 7.1-rc5 with syzkaller, as part of research at ASU's
> SEFCOM lab, we hit the crash below. Crash reports can be found here:

Have you tried it with 7.3-rc1?

>   BUG: unable to handle page fault for address: ffffffffffffff9f
>   RIP: 0010:afs_put_addrlist+0x43/0x250 fs/afs/addr_list.c:38
>   afs_lookup_server+0xd3f/0x1020 fs/afs/server.c:243
>   afs_alloc_server_list+0x800/0x11a0 fs/afs/server_list.c:82
>   afs_create_volume+0x995/0x1290 fs/afs/volume.c:227
>   afs_get_tree+0x955/0x10b0 fs/afs/super.c:555

It looks like alist is 0xffffffffffffff9f, but it's not immediately obvious
how it could be anything other than a valid pointer at that point.

> Our reproducer.c is available upon request.

If I could have that, please?

Thanks,
David


      reply	other threads:[~2026-09-02 11:41 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-08-27 22:37 [BUG] afs: ERR_PTR dereference in afs_lookup_server() error path Farhad Alemi
2026-09-02 11:40 ` David Howells [this message]

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