From patchwork Wed Jul 3 14:52:39 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sean Young X-Patchwork-Id: 11029699 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 1C8891580 for ; Wed, 3 Jul 2019 14:52:48 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 0E0162853C for ; Wed, 3 Jul 2019 14:52:48 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 01BA1288CB; Wed, 3 Jul 2019 14:52:47 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 863412853C for ; Wed, 3 Jul 2019 14:52:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726811AbfGCOwm (ORCPT ); Wed, 3 Jul 2019 10:52:42 -0400 Received: from gofer.mess.org ([88.97.38.141]:45647 "EHLO gofer.mess.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725933AbfGCOwm (ORCPT ); Wed, 3 Jul 2019 10:52:42 -0400 Received: by gofer.mess.org (Postfix, from userid 1000) id E1CEB60A67; Wed, 3 Jul 2019 15:52:39 +0100 (BST) Date: Wed, 3 Jul 2019 15:52:39 +0100 From: Sean Young To: syzbot Cc: andreyknvl@google.com, hans.verkuil@cisco.com, keescook@chromium.org, linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, linux-usb@vger.kernel.org, mchehab@kernel.org, syzkaller-bugs@googlegroups.com Subject: [PATCH] media: technisat-usb2: break out of loop at end of buffer Message-ID: <20190703145239.ridwf2jegipnoxfz@gofer.mess.org> References: <000000000000089d7f058683115e@google.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <000000000000089d7f058683115e@google.com> User-Agent: NeoMutt/20170113 (1.7.2) Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Ensure we do not access the buffer beyond the end if no 0xff byte is encountered. Reported-by: syzbot+eaaaf38a95427be88f4b@syzkaller.appspotmail.com Signed-off-by: Sean Young Reviewed-by: Kees Cook --- drivers/media/usb/dvb-usb/technisat-usb2.c | 22 ++++++++++------------ 1 file changed, 10 insertions(+), 12 deletions(-) diff --git a/drivers/media/usb/dvb-usb/technisat-usb2.c b/drivers/media/usb/dvb-usb/technisat-usb2.c index c659e18b358b..676d233d46d5 100644 --- a/drivers/media/usb/dvb-usb/technisat-usb2.c +++ b/drivers/media/usb/dvb-usb/technisat-usb2.c @@ -608,10 +608,9 @@ static int technisat_usb2_frontend_attach(struct dvb_usb_adapter *a) static int technisat_usb2_get_ir(struct dvb_usb_device *d) { struct technisat_usb2_state *state = d->priv; - u8 *buf = state->buf; - u8 *b; - int ret; struct ir_raw_event ev; + u8 *buf = state->buf; + int i, ret; buf[0] = GET_IR_DATA_VENDOR_REQUEST; buf[1] = 0x08; @@ -647,26 +646,25 @@ static int technisat_usb2_get_ir(struct dvb_usb_device *d) return 0; /* no key pressed */ /* decoding */ - b = buf+1; #if 0 deb_rc("RC: %d ", ret); - debug_dump(b, ret, deb_rc); + debug_dump(buf + 1, ret, deb_rc); #endif ev.pulse = 0; - while (1) { - ev.pulse = !ev.pulse; - ev.duration = (*b * FIRMWARE_CLOCK_DIVISOR * FIRMWARE_CLOCK_TICK) / 1000; - ir_raw_event_store(d->rc_dev, &ev); - - b++; - if (*b == 0xff) { + for (i = 1; i < ARRAY_SIZE(state->buf); i++) { + if (buf[i] == 0xff) { ev.pulse = 0; ev.duration = 888888*2; ir_raw_event_store(d->rc_dev, &ev); break; } + + ev.pulse = !ev.pulse; + ev.duration = (buf[i] * FIRMWARE_CLOCK_DIVISOR * + FIRMWARE_CLOCK_TICK) / 1000; + ir_raw_event_store(d->rc_dev, &ev); } ir_raw_event_handle(d->rc_dev);