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=-19.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, 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 20EC9C433E0 for ; Mon, 15 Mar 2021 14:49:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E4FB964E1F for ; Mon, 15 Mar 2021 14:49:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239179AbhCOOqo (ORCPT ); Mon, 15 Mar 2021 10:46:44 -0400 Received: from mail.kernel.org ([198.145.29.99]:52488 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234625AbhCOOEe (ORCPT ); Mon, 15 Mar 2021 10:04:34 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 4C82C64F8E; Mon, 15 Mar 2021 14:04:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1615817072; bh=lv+0TvJd6eDnBA65zQK+qLe6zQ/VSNK8Tkf105+Wgi8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=WFVpLZLkGcQszZht/yBslsHWf0cnWOZhJp33nEGFxaVL2GXnA6T+CQvZuvZbuXyhu 6BmLimuKBDX3FBL5e2icrMAcvt8GlLSFNzH8RNiRBHev7mK5Uw82sn6aD9CykbpGPt ZAVyx+i5ro+eLN2K2wh/ZocqYVJnjZEur6CCq97w= From: gregkh@linuxfoundation.org To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Andy Lutomirski , Thomas Gleixner , Borislav Petkov Subject: [PATCH 5.10 275/290] x86/entry: Fix entry/exit mismatch on failed fast 32-bit syscalls Date: Mon, 15 Mar 2021 14:56:08 +0100 Message-Id: <20210315135551.327241513@linuxfoundation.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210315135541.921894249@linuxfoundation.org> References: <20210315135541.921894249@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Greg Kroah-Hartman From: Andy Lutomirski commit 5d5675df792ff67e74a500c4c94db0f99e6a10ef upstream. On a 32-bit fast syscall that fails to read its arguments from user memory, the kernel currently does syscall exit work but not syscall entry work. This confuses audit and ptrace. For example: $ ./tools/testing/selftests/x86/syscall_arg_fault_32 ... strace: pid 264258: entering, ptrace_syscall_info.op == 2 ... This is a minimal fix intended for ease of backporting. A more complete cleanup is coming. Fixes: 0b085e68f407 ("x86/entry: Consolidate 32/64 bit syscall entry") Signed-off-by: Andy Lutomirski Signed-off-by: Thomas Gleixner Signed-off-by: Borislav Petkov Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/8c82296ddf803b91f8d1e5eac89e5803ba54ab0e.1614884673.git.luto@kernel.org Signed-off-by: Greg Kroah-Hartman --- arch/x86/entry/common.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/arch/x86/entry/common.c +++ b/arch/x86/entry/common.c @@ -128,7 +128,8 @@ static noinstr bool __do_fast_syscall_32 regs->ax = -EFAULT; instrumentation_end(); - syscall_exit_to_user_mode(regs); + local_irq_disable(); + irqentry_exit_to_user_mode(regs); return false; }