linux-kernel - Re: [PATCH 1/2] HID: uhid: Fix worker destroying device without any protection

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Date:   Wed, 19 Jan 2022 15:59:47 +0100 (CET)
From:   Jiri Kosina <jikos@...nel.org>
To:     Jann Horn <jannh@...gle.com>
cc:     David Rheinsberg <david.rheinsberg@...il.com>,
        Benjamin Tissoires <benjamin.tissoires@...hat.com>,
        linux-input@...r.kernel.org,
        Roderick Colenbrander <roderick.colenbrander@...y.com>,
        linux-kernel@...r.kernel.org, stable@...r.kernel.org
Subject: Re: [PATCH 1/2] HID: uhid: Fix worker destroying device without any
 protection

On Fri, 14 Jan 2022, Jann Horn wrote:

> uhid has to run hid_add_device() from workqueue context while allowing
> parallel use of the userspace API (which is protected with ->devlock).
> But hid_add_device() can fail. Currently, that is handled by immediately
> destroying the associated HID device, without using ->devlock - but if
> there are concurrent requests from userspace, that's wrong and leads to
> NULL dereferences and/or memory corruption (via use-after-free).
> 
> Fix it by leaving the HID device as-is in the worker. We can clean it up
> later, either in the UHID_DESTROY command handler or in the ->release()
> handler.
> 
> Cc: stable@...r.kernel.org
> Fixes: 67f8ecc550b5 ("HID: uhid: fix timeout when probe races with IO")
> Signed-off-by: Jann Horn <jannh@...gle.com>

I've queued both patches for 5.17, thanks a lot for fixing this.

-- 
Jiri Kosina
SUSE Labs