From patchwork Thu Jun 10 21:42:59 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Arnd Bergmann X-Patchwork-Id: 457871 Delivered-To: patch@linaro.org Received: by 2002:a02:735a:0:0:0:0:0 with SMTP id a26csp13475jae; Thu, 10 Jun 2021 14:44:58 -0700 (PDT) X-Google-Smtp-Source: ABdhPJyMmhOn6jcXxeLI3yI8sgaGo4MwDPXut5LqDrorZMkd6DYkqZMYhwYCgj+38TbDrE05EC7a X-Received: by 2002:a17:906:2456:: with SMTP id a22mr516569ejb.496.1623361498610; Thu, 10 Jun 2021 14:44:58 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1623361498; cv=none; d=google.com; s=arc-20160816; b=dS0DlXDYVqS+WfhTXV0TR/gYTPVja7I3mGVdwSyxKZXIxXoyZTeu5W7XlQ05bSBibC YC3pjgKdgLTIUtJ3IkG4XsyTSSqHqXMiNnL7R1b//Q5FYMWfjfL9zgabfKwcZTjy7m7s W04ZyNIvzigLAtD+hQtF7lNcM0T4Ox4VeJVHVtFGxjI3e7N2EMNJV2KANAuXwlwFIWnG TBgvbtoFnfnPUolwpGjvocpIqR3eoXLIX8Nxl6swIl3J+pbgoISeZkSYExV9pX+2smrS fU5/Z3Zt+wHqadA9YDjABUQ0GL5zyfUOSAjCHqmQ6Kf8a4OIaqoYe6SDBCa6g0g3n6P9 zpag== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:mime-version :references:in-reply-to:message-id:date:subject:cc:to:from :dkim-signature; bh=K+VAPHR3xscPW/+yiphnPFzaBtWMPH4y8wTJX/uM/cQ=; b=yeCgFUoIoFu/vcaQmrgSmlu7gib1RMaoAAisPI1XdPPAAnYJ9bQsVflYjPrm/loz+K jyRSOzhe8p6jXXWW+j6ldm8i7R7U2AeSjIu/kXMzjU/u/ydad4oSxAAmWi2Xb4iNyIig pLkRwenkH35X7yr60Ez/SWrC4VCdpnI6JaVnzVKYEM/O8uqJ8/o0KuX8JGyrXM/OBiUJ 83GHwzGdkOv1J7u4tSv/bWWmWynf1Xkd+U95pXrExh6cID91+uVGsi6upoPNSyUImrJL 8ozErhRe4k/+kzT1HM4NDfspbnBHNBsSfCJ5jouoWcOyGCQKB9SUxGnWb10Blzex7SpX W+eQ== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@kernel.org header.s=k20201202 header.b="sIaA/5YS"; spf=pass (google.com: domain of linux-media-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-media-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [23.128.96.18]) by mx.google.com with ESMTP id n2si3268404edi.195.2021.06.10.14.44.58; Thu, 10 Jun 2021 14:44:58 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-media-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=pass header.i=@kernel.org header.s=k20201202 header.b="sIaA/5YS"; spf=pass (google.com: domain of linux-media-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-media-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230421AbhFJVqv (ORCPT + 4 others); Thu, 10 Jun 2021 17:46:51 -0400 Received: from mail.kernel.org ([198.145.29.99]:53998 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230392AbhFJVqv (ORCPT ); Thu, 10 Jun 2021 17:46:51 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id D1D6B6140F; Thu, 10 Jun 2021 21:44:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1623361494; bh=h6jahKwcgZr9GHnO++ojYKPMb/hANxKqOaLsulGV0cw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=sIaA/5YSYjx9kMI1Yht3eYZ5txa7jyv52I+6L1W69mtk9pFIVdBMTNWF641QcBSHm qcBzGAwbxzK3FDM0ABwG66NI41i5TkZKRM7M/8Dj0UWI94KLl3euZ01V4ErP3oDnWL 61Tqv1TaQF0hpCdWqmaA4gB2+H8uLKdoAB7TdoT2BkD/mjP1JLQWlYmPEbsZ6VYVSy P/x7SeZytuyLhkd3AQD1YagF3ksKS1RTr8Hs0nwE1tXc/Oi3BEQBtwK/xvhBOQ8GL+ rxECKVmcV0ob35U8sYRWDPGN+pSj6GhQZ/EBU5CbAtdGtbsFX6iP1CEliX0PtCdYdD EaNflRbpH2Row== From: Arnd Bergmann To: Hans Verkuil , Mauro Carvalho Chehab Cc: Arnd Bergmann , "Lad, Prabhakar" , Eduardo Valentin , Sakari Ailus , Greg Kroah-Hartman , Vaibhav Gupta , Liu Shixin , Laurent Pinchart , Jacopo Mondi , Andy Shevchenko , linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, linux-staging@lists.linux.dev, syzbot+142888ffec98ab194028@syzkaller.appspotmail.com Subject: [PATCH v2 1/7] media: v4l2-core: ignore native time32 ioctls on 64-bit Date: Thu, 10 Jun 2021 23:42:59 +0200 Message-Id: <20210610214305.4170835-2-arnd@kernel.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20210610214305.4170835-1-arnd@kernel.org> References: <20210610214305.4170835-1-arnd@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org From: Arnd Bergmann Syzbot found that passing ioctl command 0xc0505609 into a 64-bit kernel from a 32-bit process causes uninitialized kernel memory to get passed to drivers instead of the user space data: BUG: KMSAN: uninit-value in check_array_args drivers/media/v4l2-core/v4l2-ioctl.c:3041 [inline] BUG: KMSAN: uninit-value in video_usercopy+0x1631/0x3d30 drivers/media/v4l2-core/v4l2-ioctl.c:3315 CPU: 0 PID: 19595 Comm: syz-executor.4 Not tainted 5.11.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x21c/0x280 lib/dump_stack.c:120 kmsan_report+0xfb/0x1e0 mm/kmsan/kmsan_report.c:118 __msan_warning+0x5f/0xa0 mm/kmsan/kmsan_instr.c:197 check_array_args drivers/media/v4l2-core/v4l2-ioctl.c:3041 [inline] video_usercopy+0x1631/0x3d30 drivers/media/v4l2-core/v4l2-ioctl.c:3315 video_ioctl2+0x9f/0xb0 drivers/media/v4l2-core/v4l2-ioctl.c:3391 v4l2_ioctl+0x255/0x290 drivers/media/v4l2-core/v4l2-dev.c:360 v4l2_compat_ioctl32+0x2c6/0x370 drivers/media/v4l2-core/v4l2-compat-ioctl32.c:1248 __do_compat_sys_ioctl fs/ioctl.c:842 [inline] __se_compat_sys_ioctl+0x53d/0x1100 fs/ioctl.c:793 __ia32_compat_sys_ioctl+0x4a/0x70 fs/ioctl.c:793 do_syscall_32_irqs_on arch/x86/entry/common.c:79 [inline] __do_fast_syscall_32+0x102/0x160 arch/x86/entry/common.c:141 do_fast_syscall_32+0x6a/0xc0 arch/x86/entry/common.c:166 do_SYSENTER_32+0x73/0x90 arch/x86/entry/common.c:209 entry_SYSENTER_compat_after_hwframe+0x4d/0x5c The time32 commands are defined but were never meant to be called on 64-bit machines, as those have always used time64 interfaces. I missed this in my patch that introduced the time64 handling on 32-bit platforms. The problem in this case is the mismatch of one function checking for the numeric value of the command and another function checking for the type of process (native vs compat) instead, with the result being that for this combination, nothing gets copied into the buffer at all. Avoid this by only trying to convert the time32 commands when running on a 32-bit kernel where these are defined in a meaningful way. Fixes: 577c89b0ce72 ("media: v4l2-core: fix v4l2_buffer handling for time64 ABI") Reported-by: syzbot+142888ffec98ab194028@syzkaller.appspotmail.com Tested-by: Hans Verkuil Signed-off-by: Arnd Bergmann --- This patch adds two more changes than the version that Hans tested Signed-off-by: Arnd Bergmann --- drivers/media/v4l2-core/v4l2-ioctl.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) -- 2.29.2 diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c index 2673f51aafa4..58df927aec7e 100644 --- a/drivers/media/v4l2-core/v4l2-ioctl.c +++ b/drivers/media/v4l2-core/v4l2-ioctl.c @@ -3073,7 +3073,7 @@ static int check_array_args(unsigned int cmd, void *parg, size_t *array_size, static unsigned int video_translate_cmd(unsigned int cmd) { switch (cmd) { -#ifdef CONFIG_COMPAT_32BIT_TIME +#if !defined(CONFIG_64BIT) && defined(CONFIG_COMPAT_32BIT_TIME) case VIDIOC_DQEVENT_TIME32: return VIDIOC_DQEVENT; case VIDIOC_QUERYBUF_TIME32: @@ -3127,7 +3127,7 @@ static int video_get_user(void __user *arg, void *parg, err = v4l2_compat_get_user(arg, parg, cmd); } else { switch (cmd) { -#ifdef CONFIG_COMPAT_32BIT_TIME +#if !defined(CONFIG_64BIT) && defined(CONFIG_COMPAT_32BIT_TIME) case VIDIOC_QUERYBUF_TIME32: case VIDIOC_QBUF_TIME32: case VIDIOC_DQBUF_TIME32: @@ -3182,7 +3182,7 @@ static int video_put_user(void __user *arg, void *parg, return v4l2_compat_put_user(arg, parg, cmd); switch (cmd) { -#ifdef CONFIG_COMPAT_32BIT_TIME +#if !defined(CONFIG_64BIT) && defined(CONFIG_COMPAT_32BIT_TIME) case VIDIOC_DQEVENT_TIME32: { struct v4l2_event *ev = parg; struct v4l2_event_time32 ev32;