From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D9007C2BBE2 for ; Sun, 8 Dec 2019 13:58:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B3B40206E0 for ; Sun, 8 Dec 2019 13:58:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727048AbfLHN6M (ORCPT ); Sun, 8 Dec 2019 08:58:12 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:60048 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726646AbfLHNyl (ORCPT ); Sun, 8 Dec 2019 08:54:41 -0500 Received: from [192.168.4.242] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1idx1C-0007ds-DL; Sun, 08 Dec 2019 13:54:38 +0000 Received: from ben by deadeye with local (Exim 4.93-RC1) (envelope-from ) id 1idx1B-0002MU-9B; Sun, 08 Dec 2019 13:54:37 +0000 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, Denis Kirjanov , "Alan Stern" , "Jiri Kosina" Date: Sun, 08 Dec 2019 13:53:10 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) X-Patchwork-Hint: ignore Subject: [PATCH 3.16 26/72] HID: prodikeys: Fix general protection fault during probe In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.242 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org 3.16.79-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Alan Stern commit 98375b86c79137416e9fd354177b85e768c16e56 upstream. The syzbot fuzzer provoked a general protection fault in the hid-prodikeys driver: kasan: CONFIG_KASAN_INLINE enabled kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] SMP KASAN CPU: 0 PID: 12 Comm: kworker/0:1 Not tainted 5.3.0-rc5+ #28 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: usb_hub_wq hub_event RIP: 0010:pcmidi_submit_output_report drivers/hid/hid-prodikeys.c:300 [inline] RIP: 0010:pcmidi_set_operational drivers/hid/hid-prodikeys.c:558 [inline] RIP: 0010:pcmidi_snd_initialise drivers/hid/hid-prodikeys.c:686 [inline] RIP: 0010:pk_probe+0xb51/0xfd0 drivers/hid/hid-prodikeys.c:836 Code: 0f 85 50 04 00 00 48 8b 04 24 4c 89 7d 10 48 8b 58 08 e8 b2 53 e4 fc 48 8b 54 24 20 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 <80> 3c 02 00 0f 85 13 04 00 00 48 ba 00 00 00 00 00 fc ff df 49 8b The problem is caused by the fact that pcmidi_get_output_report() will return an error if the HID device doesn't provide the right sort of output report, but pcmidi_set_operational() doesn't bother to check the return code and assumes the function call always succeeds. This patch adds the missing check and aborts the probe operation if necessary. Reported-and-tested-by: syzbot+1088533649dafa1c9004@syzkaller.appspotmail.com Signed-off-by: Alan Stern Signed-off-by: Jiri Kosina Signed-off-by: Ben Hutchings --- drivers/hid/hid-prodikeys.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) --- a/drivers/hid/hid-prodikeys.c +++ b/drivers/hid/hid-prodikeys.c @@ -557,10 +557,14 @@ static void pcmidi_setup_extra_keys( static int pcmidi_set_operational(struct pcmidi_snd *pm) { + int rc; + if (pm->ifnum != 1) return 0; /* only set up ONCE for interace 1 */ - pcmidi_get_output_report(pm); + rc = pcmidi_get_output_report(pm); + if (rc < 0) + return rc; pcmidi_submit_output_report(pm, 0xc1); return 0; } @@ -689,7 +693,11 @@ static int pcmidi_snd_initialise(struct spin_lock_init(&pm->rawmidi_in_lock); init_sustain_timers(pm); - pcmidi_set_operational(pm); + err = pcmidi_set_operational(pm); + if (err < 0) { + pk_error("failed to find output report\n"); + goto fail_register; + } /* register it */ err = snd_card_register(card);