linux-kernel - Re: [PATCH] HID: steam: fix deadlock with input devices.

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]

Message-ID: <nycvar.YFH.7.76.1903181444420.19912@cbobk.fhfr.pm>
Date:   Mon, 18 Mar 2019 14:44:54 +0100 (CET)
From:   Jiri Kosina <jikos@...nel.org>
To:     Rodrigo Rivas Costa <rodrigorivascosta@...il.com>
cc:     Benjamin Tissoires <benjamin.tissoires@...hat.com>,
        "Pierre-Loup A. Griffais" <pgriffais@...vesoftware.com>,
        lkml <linux-kernel@...r.kernel.org>,
        linux-input <linux-input@...r.kernel.org>,
        Simon Gene Gottlieb <simon@...tliebtfreitag.de>
Subject: Re: [PATCH] HID: steam: fix deadlock with input devices.

On Fri, 15 Mar 2019, Rodrigo Rivas Costa wrote:

> When using this driver with the wireless dongle and some usermode
> program that monitors every input device (acpid, for example), while
> another usermode client opens and closes the low-level device
> repeadedly, the system eventually deadlocks.
> 
> The reason is that steam_input_register_device() must not be called with
> the mutex held, because the input subsystem has its own synchronization
> that clashes with this one: it is possible that steam_input_open() is
> called before input_register_device() returns, and since
> steam_input_open() needs to lock the mutex, it deadlocks.
> 
> However we must hold the mutex when calling any function that sends
> commands to the controller. If not, random commands end up falling fail.
> 
> Reported-by: Simon Gene Gottlieb <simon@...tliebtfreitag.de>
> Signed-off-by: Rodrigo Rivas Costa <rodrigorivascosta@...il.com>
> Tested-by: Simon Gene Gottlieb <simon@...tliebtfreitag.de>

Applied to for-5.1/upstream-fixes, thanks.

-- 
Jiri Kosina
SUSE Labs