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 52652C7EE30 for ; Fri, 3 Mar 2023 21:54:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232979AbjCCVyg (ORCPT ); Fri, 3 Mar 2023 16:54:36 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48736 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233059AbjCCVxw (ORCPT ); Fri, 3 Mar 2023 16:53:52 -0500 Received: from sin.source.kernel.org (sin.source.kernel.org [IPv6:2604:1380:40e1:4800::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E1EDC6A046; Fri, 3 Mar 2023 13:48:15 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by sin.source.kernel.org (Postfix) with ESMTPS id EA6BECE22AA; Fri, 3 Mar 2023 21:48:14 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id BF155C4339C; Fri, 3 Mar 2023 21:48:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1677880094; bh=SziSnG/v3cJgd3wlsrO5t7jv6w2gKjB1KtajekztW5o=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=SLKDiDBKC5PIaVvKsJRtXO1+nbPzFpS/Wd4dGcz2wMpC5jfo0l4J7ts/z+U+6ksc0 fFIDjXN/a5S32UiPO2swzsVVj0e1BIbLg9h9YpwoX27zuBttKX5CYka9mclI8mwaVd QaUYOo3Ur6PFBjXefQ6HXNi9w1u3rqgM/HcOHyXmdDIzNvMdbCavKbkiWtOvMu5YbZ yprLfPf8NMpXUA+yUNcOd4w+aTgcdksbMMn0ER9CphueYER545oAsd36vpt4px/VfU 9tL1j80SOw7f2VP+3J+rlPLJwdN24NU3ss8RdQO8ducf3bsCkeBFNXkKb8zXZtGCjE j3oe2eHCoFWZw== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Kees Cook , ionut_n2001@yahoo.com, Laurent Pinchart , Sasha Levin , mchehab@kernel.org, linux-media@vger.kernel.org Subject: [PATCH AUTOSEL 5.4 05/20] media: uvcvideo: Silence memcpy() run-time false positive warnings Date: Fri, 3 Mar 2023 16:47:51 -0500 Message-Id: <20230303214806.1453287-5-sashal@kernel.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230303214806.1453287-1-sashal@kernel.org> References: <20230303214806.1453287-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Kees Cook [ Upstream commit b839212988575c701aab4d3d9ca15e44c87e383c ] The memcpy() in uvc_video_decode_meta() intentionally copies across the length and flags members and into the trailing buf flexible array. Split the copy so that the compiler can better reason about (the lack of) buffer overflows here. Avoid the run-time false positive warning: memcpy: detected field-spanning write (size 12) of single field "&meta->length" at drivers/media/usb/uvc/uvc_video.c:1355 (size 1) Additionally fix a typo in the documentation for struct uvc_meta_buf. Reported-by: ionut_n2001@yahoo.com Link: https://bugzilla.kernel.org/show_bug.cgi?id=216810 Signed-off-by: Kees Cook Reviewed-by: Laurent Pinchart Signed-off-by: Laurent Pinchart Signed-off-by: Sasha Levin --- drivers/media/usb/uvc/uvc_video.c | 4 +++- include/uapi/linux/uvcvideo.h | 2 +- 2 files changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/media/usb/uvc/uvc_video.c b/drivers/media/usb/uvc/uvc_video.c index 698aecf1aad48..e676a9ef6f0d6 100644 --- a/drivers/media/usb/uvc/uvc_video.c +++ b/drivers/media/usb/uvc/uvc_video.c @@ -1308,7 +1308,9 @@ static void uvc_video_decode_meta(struct uvc_streaming *stream, if (has_scr) memcpy(stream->clock.last_scr, scr, 6); - memcpy(&meta->length, mem, length); + meta->length = mem[0]; + meta->flags = mem[1]; + memcpy(meta->buf, &mem[2], length - 2); meta_buf->bytesused += length + sizeof(meta->ns) + sizeof(meta->sof); uvc_trace(UVC_TRACE_FRAME, diff --git a/include/uapi/linux/uvcvideo.h b/include/uapi/linux/uvcvideo.h index f80f05b3c423f..2140923661934 100644 --- a/include/uapi/linux/uvcvideo.h +++ b/include/uapi/linux/uvcvideo.h @@ -86,7 +86,7 @@ struct uvc_xu_control_query { * struct. The first two fields are added by the driver, they can be used for * clock synchronisation. The rest is an exact copy of a UVC payload header. * Only complete objects with complete buffers are included. Therefore it's - * always sizeof(meta->ts) + sizeof(meta->sof) + meta->length bytes large. + * always sizeof(meta->ns) + sizeof(meta->sof) + meta->length bytes large. */ struct uvc_meta_buf { __u64 ns; -- 2.39.2