Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753445AbdHRNxP (ORCPT ); Fri, 18 Aug 2017 09:53:15 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:55332 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752682AbdHRNPo (ORCPT ); Fri, 18 Aug 2017 09:15:44 -0400 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, "Mauro Carvalho Chehab" , "Sri Deevi" , "Hans Verkuil" , "Johan Hovold" Date: Fri, 18 Aug 2017 14:13:20 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 037/134] [media] cx231xx-audio: fix NULL-deref at probe In-Reply-To: X-SA-Exim-Connect-IP: 82.70.136.246 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1926 Lines: 63 3.16.47-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Johan Hovold commit 65f921647f4c89a2068478c89691f39b309b58f7 upstream. Make sure to check the number of endpoints to avoid dereferencing a NULL-pointer or accessing memory beyond the endpoint array should a malicious device lack the expected endpoints. Fixes: e0d3bafd0258 ("V4L/DVB (10954): Add cx231xx USB driver") Cc: Sri Deevi Signed-off-by: Johan Hovold Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Ben Hutchings --- drivers/media/usb/cx231xx/cx231xx-audio.c | 17 +++++++++++++++-- 1 file changed, 15 insertions(+), 2 deletions(-) --- a/drivers/media/usb/cx231xx/cx231xx-audio.c +++ b/drivers/media/usb/cx231xx/cx231xx-audio.c @@ -699,6 +699,11 @@ static int cx231xx_audio_init(struct cx2 hs_config_info[0].interface_info. audio_index + 1]; + if (uif->altsetting[0].desc.bNumEndpoints < isoc_pipe + 1) { + err = -ENODEV; + goto err_free_card; + } + adev->end_point_addr = uif->altsetting[0].endpoint[isoc_pipe].desc. bEndpointAddress; @@ -714,8 +719,14 @@ static int cx231xx_audio_init(struct cx2 } for (i = 0; i < adev->num_alt; i++) { - u16 tmp = - le16_to_cpu(uif->altsetting[i].endpoint[isoc_pipe].desc. + u16 tmp; + + if (uif->altsetting[i].desc.bNumEndpoints < isoc_pipe + 1) { + err = -ENODEV; + goto err_free_pkt_size; + } + + tmp = le16_to_cpu(uif->altsetting[i].endpoint[isoc_pipe].desc. wMaxPacketSize); adev->alt_max_pkt_size[i] = (tmp & 0x07ff) * (((tmp & 0x1800) >> 11) + 1); @@ -725,6 +736,8 @@ static int cx231xx_audio_init(struct cx2 return 0; +err_free_pkt_size: + kfree(adev->alt_max_pkt_size); err_free_card: snd_card_free(card);