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 3528DC7EE32 for ; Fri, 3 Mar 2023 21:51:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232777AbjCCVva (ORCPT ); Fri, 3 Mar 2023 16:51:30 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37808 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232822AbjCCVtl (ORCPT ); Fri, 3 Mar 2023 16:49:41 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 88CD86C19C; Fri, 3 Mar 2023 13:46:01 -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 ams.source.kernel.org (Postfix) with ESMTPS id 89064B81A29; Fri, 3 Mar 2023 21:45:43 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 797C4C433A0; Fri, 3 Mar 2023 21:45:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1677879943; bh=3roV8uW1v31n5edmx9W0JG+kRuQVOwex91joNPZwoSw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=i7k6ykjkZFPalh0D9BritICqdwA6GdY2ynIsenJ2CVPpL1rxC+ruN0DRj3gIwBcCc JNY+aVbpS6/9tppRaNnapX5DaPLmqNfxE+PUE8XlJ0XpJuh7u9Yprc3sIEEjMeytzw AW7UiHk0rDS5D5PbrXc0KwmKpnLSLgiOxX/lWBNO84lT7ueLVM9BlCp/Rea5l9LxiJ mW1BRGFjxosntulYabPm3HYLzuMlwyVN/557YrzLMpiPGj1EsuypyeNp3Xa+lVHyR8 FgHF431vCTjZHXRRT9RPYpp5bIm7bLQWm8qAawzmgkcl4ykfipwBFwTx4Q9qV6KZpA EMSPMYzM+s+IA== 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 5.15 07/50] media: uvcvideo: Silence memcpy() run-time false positive warnings Date: Fri, 3 Mar 2023 16:44:48 -0500 Message-Id: <20230303214531.1450154-7-sashal@kernel.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230303214531.1450154-1-sashal@kernel.org> References: <20230303214531.1450154-1-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: stable@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 af2c6cb9fa3c4..f477cfbbb905a 100644 --- a/drivers/media/usb/uvc/uvc_video.c +++ b/drivers/media/usb/uvc/uvc_video.c @@ -1334,7 +1334,9 @@ 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_dbg(stream->dev, FRAME, diff --git a/include/uapi/linux/uvcvideo.h b/include/uapi/linux/uvcvideo.h index 8288137387c0d..a9d0a64007ba5 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