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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2D187C433EF for ; Wed, 22 Dec 2021 10:47:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244255AbhLVKrF (ORCPT ); Wed, 22 Dec 2021 05:47:05 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39322 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240018AbhLVKrF (ORCPT ); Wed, 22 Dec 2021 05:47:05 -0500 Received: from mail.turbocat.net (turbocat.net [IPv6:2a01:4f8:c17:6c4b::2]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F0CE8C061574 for ; Wed, 22 Dec 2021 02:47:04 -0800 (PST) Received: from [10.36.2.165] (unknown [178.17.145.105]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mail.turbocat.net (Postfix) with ESMTPSA id 6AB8C2601E9 for ; Wed, 22 Dec 2021 11:47:02 +0100 (CET) Message-ID: <06c00e24-cdad-8776-9fc1-2c0f3db5af9a@selasky.org> Date: Wed, 22 Dec 2021 11:46:55 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:91.0) Gecko/20100101 Thunderbird/91.4.1 To: linux-media@vger.kernel.org Content-Language: en-US From: Hans Petter Selasky Subject: [PATCH] Make sure we parse really received data. Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org Hi, USB control requests may return less data than we ask for. Found using valgrind and webcamd on FreeBSD. ==15522== Conditional jump or move depends on uninitialised value(s) ==15522== at 0x662EF4: uvc_fixup_video_ctrl (uvc_video.c:135) ==15522== by 0x662EF4: uvc_get_video_ctrl (uvc_video.c:297) ==15522== by 0x6640B0: uvc_video_init (uvc_video.c:2078) ==15522== by 0x65E79D: uvc_register_video (uvc_driver.c:2258) ==15522== by 0x65E79D: uvc_register_terms (uvc_driver.c:2300) ==15522== by 0x65E79D: uvc_register_chains (uvc_driver.c:2321) ==15522== by 0x65E79D: uvc_probe (uvc_driver.c:2463) ==15522== by 0x3C8F46: usb_linux_probe_p (linux_usb.c:449) ==15522== by 0x75B4B2: main (webcamd.c:1021) ==15522== Uninitialised value was created by a heap allocation ==15522== at 0x4853844: malloc (in /usr/local/libexec/valgrind/vgpreload_memcheck-amd64-freebsd.so) ==15522== by 0x3BC8A4: kmalloc (linux_func.c:1807) ==15522== by 0x662C8C: uvc_get_video_ctrl (uvc_video.c:229) ==15522== by 0x6640B0: uvc_video_init (uvc_video.c:2078) ==15522== by 0x65E79D: uvc_register_video (uvc_driver.c:2258) ==15522== by 0x65E79D: uvc_register_terms (uvc_driver.c:2300) ==15522== by 0x65E79D: uvc_register_chains (uvc_driver.c:2321) ==15522== by 0x65E79D: uvc_probe (uvc_driver.c:2463) ==15522== by 0x3C8F46: usb_linux_probe_p (linux_usb.c:449) ==15522== by 0x75B4B2: main (webcamd.c:1021) Signed-off-by: Hans Petter Selasky --- drivers/media/usb/uvc/uvc_video.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/media/usb/uvc/uvc_video.c b/drivers/media/usb/uvc/uvc_video.c index 9f37eaf28ce7..6233703f9a50 100644 --- a/drivers/media/usb/uvc/uvc_video.c +++ b/drivers/media/usb/uvc/uvc_video.c @@ -258,7 +258,11 @@ static int uvc_get_video_ctrl(struct uvc_streaming *stream, query == UVC_GET_DEF) return -EIO; - data = kmalloc(size, GFP_KERNEL); + /* + * Make sure we parse really received data + * by allocating a zeroed buffer. + */ + data = kzalloc(size, GFP_KERNEL); if (data == NULL) return -ENOMEM; -- 2.34.1