From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753253AbdCMM43 (ORCPT ); Mon, 13 Mar 2017 08:56:29 -0400 Received: from mail-lf0-f68.google.com ([209.85.215.68]:35816 "EHLO mail-lf0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750814AbdCMMye (ORCPT ); Mon, 13 Mar 2017 08:54:34 -0400 From: Johan Hovold To: Mauro Carvalho Chehab Cc: Hans Verkuil , linux-media@vger.kernel.org, linux-kernel@vger.kernel.org, Johan Hovold , stable , Thierry MERLE Subject: [PATCH 2/6] [media] usbvision: fix NULL-deref at probe Date: Mon, 13 Mar 2017 13:53:55 +0100 Message-Id: <20170313125359.29394-3-johan@kernel.org> X-Mailer: git-send-email 2.12.0 In-Reply-To: <20170313125359.29394-1-johan@kernel.org> References: <20170313125359.29394-1-johan@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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: 2a9f8b5d25be ("V4L/DVB (5206): Usbvision: set alternate interface modification") Cc: stable # 2.6.21 Cc: Thierry MERLE Signed-off-by: Johan Hovold --- drivers/media/usb/usbvision/usbvision-video.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/media/usb/usbvision/usbvision-video.c b/drivers/media/usb/usbvision/usbvision-video.c index f5c635a67d74..f9c3325aa4d4 100644 --- a/drivers/media/usb/usbvision/usbvision-video.c +++ b/drivers/media/usb/usbvision/usbvision-video.c @@ -1501,7 +1501,14 @@ static int usbvision_probe(struct usb_interface *intf, } for (i = 0; i < usbvision->num_alt; i++) { - u16 tmp = le16_to_cpu(uif->altsetting[i].endpoint[1].desc. + u16 tmp; + + if (uif->altsetting[i].desc.bNumEndpoints < 2) { + ret = -ENODEV; + goto err_pkt; + } + + tmp = le16_to_cpu(uif->altsetting[i].endpoint[1].desc. wMaxPacketSize); usbvision->alt_max_pkt_size[i] = (tmp & 0x07ff) * (((tmp & 0x1800) >> 11) + 1); -- 2.12.0