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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham 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 70F6CC4360C for ; Mon, 14 Oct 2019 02:08:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4F4D72067B for ; Mon, 14 Oct 2019 02:08:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729762AbfJNCIq (ORCPT ); Sun, 13 Oct 2019 22:08:46 -0400 Received: from shells.gnugeneration.com ([66.240.222.126]:48138 "EHLO shells.gnugeneration.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729494AbfJNCIp (ORCPT ); Sun, 13 Oct 2019 22:08:45 -0400 Received: by shells.gnugeneration.com (Postfix, from userid 1000) id 991AA1A40559; Sun, 13 Oct 2019 19:08:45 -0700 (PDT) Date: Sun, 13 Oct 2019 19:08:45 -0700 From: Vito Caputo To: mkrufky@linuxtv.org Cc: linux-media@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] media: cxusb: detect cxusb_ctrl_msg error in query Message-ID: <20191014020845.247utwi3pjbvb6il@shells.gnugeneration.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: NeoMutt/20170113 (1.7.2) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Don't use uninitialized ircode[] in cxusb_rc_query() when cxusb_ctrl_msg() fails to populate its contents. syzbot reported: dvb-usb: bulk message failed: -22 (1/-30591) ===================================================== BUG: KMSAN: uninit-value in ir_lookup_by_scancode drivers/media/rc/rc-main.c:494 [inline] BUG: KMSAN: uninit-value in rc_g_keycode_from_table drivers/media/rc/rc-main.c:582 [inline] BUG: KMSAN: uninit-value in rc_keydown+0x1a6/0x6f0 drivers/media/rc/rc-main.c:816 CPU: 1 PID: 11436 Comm: kworker/1:2 Not tainted 5.3.0-rc7+ #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events dvb_usb_read_remote_control Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x191/0x1f0 lib/dump_stack.c:113 kmsan_report+0x13a/0x2b0 mm/kmsan/kmsan_report.c:108 __msan_warning+0x73/0xe0 mm/kmsan/kmsan_instr.c:250 bsearch+0x1dd/0x250 lib/bsearch.c:41 ir_lookup_by_scancode drivers/media/rc/rc-main.c:494 [inline] rc_g_keycode_from_table drivers/media/rc/rc-main.c:582 [inline] rc_keydown+0x1a6/0x6f0 drivers/media/rc/rc-main.c:816 cxusb_rc_query+0x2e1/0x360 drivers/media/usb/dvb-usb/cxusb.c:548 dvb_usb_read_remote_control+0xf9/0x290 drivers/media/usb/dvb-usb/dvb-usb-remote.c:261 process_one_work+0x1572/0x1ef0 kernel/workqueue.c:2269 worker_thread+0x111b/0x2460 kernel/workqueue.c:2415 kthread+0x4b5/0x4f0 kernel/kthread.c:256 ret_from_fork+0x35/0x40 arch/x86/entry/entry_64.S:355 Uninit was stored to memory at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:150 [inline] kmsan_internal_chain_origin+0xd2/0x170 mm/kmsan/kmsan.c:314 __msan_chain_origin+0x6b/0xe0 mm/kmsan/kmsan_instr.c:184 rc_g_keycode_from_table drivers/media/rc/rc-main.c:583 [inline] rc_keydown+0x2c4/0x6f0 drivers/media/rc/rc-main.c:816 cxusb_rc_query+0x2e1/0x360 drivers/media/usb/dvb-usb/cxusb.c:548 dvb_usb_read_remote_control+0xf9/0x290 drivers/media/usb/dvb-usb/dvb-usb-remote.c:261 process_one_work+0x1572/0x1ef0 kernel/workqueue.c:2269 worker_thread+0x111b/0x2460 kernel/workqueue.c:2415 kthread+0x4b5/0x4f0 kernel/kthread.c:256 ret_from_fork+0x35/0x40 arch/x86/entry/entry_64.S:355 Local variable description: ----ircode@cxusb_rc_query Variable was created at: cxusb_rc_query+0x4d/0x360 drivers/media/usb/dvb-usb/cxusb.c:543 dvb_usb_read_remote_control+0xf9/0x290 drivers/media/usb/dvb-usb/dvb-usb-remote.c:261 Signed-off-by: Vito Caputo Reported-by: syzbot --- drivers/media/usb/dvb-usb/cxusb.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/media/usb/dvb-usb/cxusb.c b/drivers/media/usb/dvb-usb/cxusb.c index f02fa0a67aa4..fac19ec46089 100644 --- a/drivers/media/usb/dvb-usb/cxusb.c +++ b/drivers/media/usb/dvb-usb/cxusb.c @@ -521,7 +521,8 @@ static int cxusb_rc_query(struct dvb_usb_device *d) { u8 ircode[4]; - cxusb_ctrl_msg(d, CMD_GET_IR_CODE, NULL, 0, ircode, 4); + if (cxusb_ctrl_msg(d, CMD_GET_IR_CODE, NULL, 0, ircode, 4) < 0) + return 0; if (ircode[2] || ircode[3]) rc_keydown(d->rc_dev, RC_PROTO_NEC, -- 2.11.0