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=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=unavailable 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 712D5C7618B for ; Wed, 24 Jul 2019 13:15:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 545CB22ADA for ; Wed, 24 Jul 2019 13:15:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728487AbfGXNPY (ORCPT ); Wed, 24 Jul 2019 09:15:24 -0400 Received: from mx2.suse.de ([195.135.220.15]:44422 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726514AbfGXNPY (ORCPT ); Wed, 24 Jul 2019 09:15:24 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 09A4AAE32; Wed, 24 Jul 2019 13:15:22 +0000 (UTC) Date: Wed, 24 Jul 2019 15:15:21 +0200 Message-ID: From: Takashi Iwai To: Andrey Konovalov Cc: Hillf Danton , Alan Stern , syzbot , Greg Kroah-Hartman , "Gustavo A. R. Silva" , LKML , USB list , syzkaller-bugs Subject: Re: WARNING in snd_usb_motu_microbookii_communicate/usb_submit_urb In-Reply-To: References: <000000000000acb99a058b0d5741@google.com> <000000000000ac8f77058e0d11e9@google.com> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI/1.14.6 (Maruoka) FLIM/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL/10.8 Emacs/25.3 (x86_64-suse-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI 1.14.6 - "Maruoka") Content-Type: text/plain; charset=US-ASCII Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org On Tue, 23 Jul 2019 19:03:29 +0200, Andrey Konovalov wrote: > > (Takashi, with your helper check syzkaller now generates a new bug > report (not reported by syzbot yet due to breakage during kernel boot > on 5.3-rc1, so see below) and I guess this has to do with a missing ep > != NULL check). > > 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: 1 PID: 74 Comm: kworker/1:1 Not tainted 5.3.0-rc1+ #40 > Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 > Workqueue: usb_hub_wq hub_event > RIP: 0010:snd_usb_pipe_sanity_check+0x80/0x130 sound/usb/helper.c:75 > Code: 48 c1 ea 03 80 3c 02 00 0f 85 b3 00 00 00 48 8b 6d 00 c1 eb 1e > 48 b8 00 00 00 00 00 fc ff df 48 8d 7d 03 48 89 fa 48 c1 ea 03 <0f> b6 > 04 02 48 89 fa 83 e2 07 38 d0 7f 04 84 c0 75 7b 48 b8 00 00 > RSP: 0018:ffff88806c33f0a8 EFLAGS: 00010246 > RAX: dffffc0000000000 RBX: 0000000000000001 RCX: ffffffff833819c2 > RDX: 0000000000000000 RSI: ffffffff833819dc RDI: 0000000000000003 > RBP: 0000000000000000 R08: ffff88806c330000 R09: fffffbfff0d1a792 > R10: fffffbfff0d1a791 R11: ffffffff868d3c8f R12: 0000000000000000 > R13: dffffc0000000000 R14: ffff88806975cc80 R15: ffff88806975c4a0 > FS: 0000000000000000(0000) GS:ffff88806d100000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 00007fcc3a48c000 CR3: 000000006861c003 CR4: 0000000000160ee0 > Call Trace: > snd_usb_accessmusic_boot_quirk sound/usb/quirks.c:835 [inline] > snd_usb_apply_boot_quirk+0xa19/0xc60 sound/usb/quirks.c:1267 > usb_audio_probe+0x2ec/0x1f40 sound/usb/card.c:576 (snip) So it's a NULL pointer returned from usb_pipe_endpoint() with an invalid pipe. The fix patch is attached below. thanks, Takashi -- 8< -- From: Takashi Iwai Subject: [PATCH] ALSA: usb-audio: Fix NULL dereference at pipe sanity check The newly introduced helper for a sanity check of a pipe causes an Oops due to the NULL pointer returned from usb_pipe_endpoint() with an invalid pipe. Let's fix it. Fixes: 801ebf1043ae ("ALSA: usb-audio: Sanity checks for each pipe and EP types") Reported-by: Andrey Konovalov Signed-off-by: Takashi Iwai --- sound/usb/helper.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/sound/usb/helper.c b/sound/usb/helper.c index 71d5f540334a..919d69e0aba3 100644 --- a/sound/usb/helper.c +++ b/sound/usb/helper.c @@ -72,6 +72,8 @@ int snd_usb_pipe_sanity_check(struct usb_device *dev, unsigned int pipe) struct usb_host_endpoint *ep; ep = usb_pipe_endpoint(dev, pipe); + if (!ep) + return -EINVAL; if (usb_pipetype(pipe) != pipetypes[usb_endpoint_type(&ep->desc)]) return -EINVAL; return 0; -- 2.16.4