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 X-Spam-Level: X-Spam-Status: No, score=-9.0 required=3.0 tests=DATE_IN_PAST_06_12, DKIMWL_WL_HIGH,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2052FC4740C for ; Mon, 9 Sep 2019 22:17:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E537B2171F for ; Mon, 9 Sep 2019 22:17:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1568067436; bh=Yl59bSCmjGQO8ga6KfcvRC+PKgjgMXblO8qVnUO1YgM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=HWR6MPZmoYhYrcbn4EpU7fZVehZUkiJC5EQD68OcD9u/Ex0VtYBD77cQoN972O0C/ mt/VhgisFPWXwZpXomsPZpeorQvwxnnC32QkGGuqwwaMDkgyrGXg2tU1zuzYw9x0/q 2vnimZGdnm7ssGhzsticyFjCm/zNGkY1Qp/nnQeg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2392208AbfIIWRP (ORCPT ); Mon, 9 Sep 2019 18:17:15 -0400 Received: from mail.kernel.org ([198.145.29.99]:46028 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2406307AbfIIWRE (ORCPT ); Mon, 9 Sep 2019 18:17:04 -0400 Received: from sasha-vm.mshome.net (unknown [62.28.240.114]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 1CEE12171F; Mon, 9 Sep 2019 22:17:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1568067423; bh=Yl59bSCmjGQO8ga6KfcvRC+PKgjgMXblO8qVnUO1YgM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=FqB+Nb9V7yzPPdNPAfhswixs2C9wdLmJGCJTbFroOY2NmDWvDJn/uW5UOcMiY5H+0 N/juWqAgNaewzVdYt31xcksrwvew8f4IMijhr2+BfnjWnUP0ar8If/kvlk39EsR1K6 BhV/F/wI+1EyrbpxaQ6CmHtIiPZd6dQHe9ERjYEo= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Peter Zijlstra , Randy Dunlap , Josh Poimboeuf , Thomas Gleixner , broonie@kernel.org, sfr@canb.auug.org.au, akpm@linux-foundation.org, mhocko@suse.cz, Sasha Levin Subject: [PATCH AUTOSEL 4.14 3/8] x86/uaccess: Don't leak the AC flags into __get_user() argument evaluation Date: Mon, 9 Sep 2019 11:41:40 -0400 Message-Id: <20190909154145.31263-3-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190909154145.31263-1-sashal@kernel.org> References: <20190909154145.31263-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Peter Zijlstra [ Upstream commit 9b8bd476e78e89c9ea26c3b435ad0201c3d7dbf5 ] Identical to __put_user(); the __get_user() argument evalution will too leak UBSAN crud into the __uaccess_begin() / __uaccess_end() region. While uncommon this was observed to happen for: drivers/xen/gntdev.c: if (__get_user(old_status, batch->status[i])) where UBSAN added array bound checking. This complements commit: 6ae865615fc4 ("x86/uaccess: Dont leak the AC flag into __put_user() argument evaluation") Tested-by Sedat Dilek Reported-by: Randy Dunlap Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Josh Poimboeuf Reviewed-by: Thomas Gleixner Cc: broonie@kernel.org Cc: sfr@canb.auug.org.au Cc: akpm@linux-foundation.org Cc: Randy Dunlap Cc: mhocko@suse.cz Cc: Josh Poimboeuf Link: https://lkml.kernel.org/r/20190829082445.GM2369@hirez.programming.kicks-ass.net Signed-off-by: Sasha Levin --- arch/x86/include/asm/uaccess.h | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h index 4111edb3188e2..9718303410614 100644 --- a/arch/x86/include/asm/uaccess.h +++ b/arch/x86/include/asm/uaccess.h @@ -451,8 +451,10 @@ do { \ ({ \ int __gu_err; \ __inttype(*(ptr)) __gu_val; \ + __typeof__(ptr) __gu_ptr = (ptr); \ + __typeof__(size) __gu_size = (size); \ __uaccess_begin_nospec(); \ - __get_user_size(__gu_val, (ptr), (size), __gu_err, -EFAULT); \ + __get_user_size(__gu_val, __gu_ptr, __gu_size, __gu_err, -EFAULT); \ __uaccess_end(); \ (x) = (__force __typeof__(*(ptr)))__gu_val; \ __builtin_expect(__gu_err, 0); \ -- 2.20.1