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=-8.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 3DC39C33CB3 for ; Wed, 15 Jan 2020 17:32:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1A41E24656 for ; Wed, 15 Jan 2020 17:32:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728998AbgAORc3 (ORCPT ); Wed, 15 Jan 2020 12:32:29 -0500 Received: from gofer.mess.org ([88.97.38.141]:59357 "EHLO gofer.mess.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726418AbgAORc3 (ORCPT ); Wed, 15 Jan 2020 12:32:29 -0500 Received: by gofer.mess.org (Postfix, from userid 1000) id DD9FE11A001; Wed, 15 Jan 2020 17:32:26 +0000 (GMT) Date: Wed, 15 Jan 2020 17:32:26 +0000 From: Sean Young To: Phong Tran Cc: mchehab@kernel.org, gregkh@linuxfoundation.org, allison@lohutok.net, tglx@linutronix.de, syzbot+6bf9606ee955b646c0e1@syzkaller.appspotmail.com, linux-media@vger.kernel.org, linux-kernel@vger.kernel.org, glider@google.com, syzkaller-bugs@googlegroups.com Subject: Re: [PATCH] media: dvb: check return value digitv_ctrl_msg Message-ID: <20200115173226.GA24471@gofer.mess.org> References: <0000000000004f3d820596d8c51c@google.com> <20191203004138.21223-1-tranmanphong@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191203004138.21223-1-tranmanphong@gmail.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, On Tue, Dec 03, 2019 at 07:41:38AM +0700, Phong Tran wrote: > For fixing syzbot "KMSAN: uninit-value in digitv_rc_query" > > In scenario testing for syzbot, failure reading from > digitv_ctrl_msg() [1]. > > Eg: > [ 91.846657][ T3844] dvb-usb: bulk message failed: -22 (7/0) > > digitv_rc_query() always return 0. But in this case a wrong thing happens. > > Reported-by: syzbot+6bf9606ee955b646c0e1@syzkaller.appspotmail.com > Tested-by: syzbot+6bf9606ee955b646c0e1@syzkaller.appspotmail.com A fix for this was already merged I'm afraid, see commit eecc70d22ae5 ("media: digitv: don't continue if remote control state can't be read"). > [1]: https://syzkaller.appspot.com/text?tag=CrashLog&x=16860a63600000 > [2]: https://groups.google.com/d/msg/syzkaller-bugs/-TXIJAZ0J9Q/T4PEUQoeAQAJ > > Signed-off-by: Phong Tran > --- > drivers/media/usb/dvb-usb/digitv.c | 12 ++++++++---- > 1 file changed, 8 insertions(+), 4 deletions(-) > > diff --git a/drivers/media/usb/dvb-usb/digitv.c b/drivers/media/usb/dvb-usb/digitv.c > index dd5bb230cec1..61bc8945e6b9 100644 > --- a/drivers/media/usb/dvb-usb/digitv.c > +++ b/drivers/media/usb/dvb-usb/digitv.c > @@ -231,17 +231,21 @@ static struct rc_map_table rc_map_digitv_table[] = { > static int digitv_rc_query(struct dvb_usb_device *d, u32 *event, int *state) > { > int i; > - u8 key[5]; > + u8 key[5] = { 0 }; The merged commit does not change this line. Why was this changed? Thanks Sean > u8 b[4] = { 0 }; > + int ret; > > *event = 0; > *state = REMOTE_NO_KEY_PRESSED; > > - digitv_ctrl_msg(d,USB_READ_REMOTE,0,NULL,0,&key[1],4); > - > + ret = digitv_ctrl_msg(d, USB_READ_REMOTE, 0, NULL, 0, &key[1], 4); > + if (ret < 0) > + return ret; > /* Tell the device we've read the remote. Not sure how necessary > this is, but the Nebula SDK does it. */ > - digitv_ctrl_msg(d,USB_WRITE_REMOTE,0,b,4,NULL,0); > + ret = digitv_ctrl_msg(d, USB_WRITE_REMOTE, 0, b, 4, NULL, 0); > + if (ret < 0) > + return ret; > > /* if something is inside the buffer, simulate key press */ > if (key[1] != 0) > -- > 2.20.1