From nobody Wed Jul 1 14:32:05 2026 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 E539BC433EF for ; Mon, 20 Dec 2021 10:48:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231424AbhLTKsU (ORCPT ); Mon, 20 Dec 2021 05:48:20 -0500 Received: from Galois.linutronix.de ([193.142.43.55]:47158 "EHLO galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231407AbhLTKsS (ORCPT ); Mon, 20 Dec 2021 05:48:18 -0500 Date: Mon, 20 Dec 2021 10:48:16 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1639997297; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=yPp1LBQFD8V9zdIDydz0LHUmOd6euwTtWzO5ulnY73w=; b=AJ8fJk3xtWqPlap2rNfFQFEhLA+c1knjayGkqac5vV9MgA91GgorCQlBWvcE3qZQSsxS1k 86BAgCBwOIrTsVI+XU6XGE7gP1HWpEVaZmdrDhJBGtHC+CCHImgUrtFDBG20WLXwflsnNl GZG2u6i1Msbzb6hk/jsuabtdATBq0EPTLS+ob6DWq3zInvKRjtazUiO1MXzXTwHfehreIk DeuQzX5q6ZP/Ae87jUfPD5ENI3uwMju98hcSeqBHmgTInoXMhWBpjjfunfM5dmjbGafztT 79HlCl2D6tG+Y1Ny7W/UhjY8f20NrvcVabA9P1MjbmcD2kCugAaRTd9XIGYlQw== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1639997297; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=yPp1LBQFD8V9zdIDydz0LHUmOd6euwTtWzO5ulnY73w=; b=hqUPIR4MhAraJi5VTQSMAgxTcfcV/XezkgaAXzphCWYm48IzY3BZErnAkVtpH/K7o8X8OU 3pXFME0WcZkyG9Ag== From: "tip-bot2 for Borislav Petkov" Sender: tip-bot2@linutronix.de Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: ras/core] x86/mce: Check regs before accessing it Cc: Dan Carpenter , Borislav Petkov , Tony Luck , x86@kernel.org, linux-kernel@vger.kernel.org In-Reply-To: <20211217102029.GA29708@kili> References: <20211217102029.GA29708@kili> MIME-Version: 1.0 Message-ID: <163999729659.23020.13602058944330070928.tip-bot2@tip-bot2> Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The following commit has been merged into the ras/core branch of tip: Commit-ID: 1acd85feba81084fcef00b73fc1601e42b77c5d8 Gitweb: https://git.kernel.org/tip/1acd85feba81084fcef00b73fc1601e42= b77c5d8 Author: Borislav Petkov AuthorDate: Fri, 17 Dec 2021 16:49:25 +01:00 Committer: Borislav Petkov CommitterDate: Mon, 20 Dec 2021 11:41:02 +01:00 x86/mce: Check regs before accessing it Commit in Fixes accesses pt_regs before checking whether it is NULL or not. Make sure the NULL pointer check happens first. Fixes: 0a5b288e85bb ("x86/mce: Prevent severity computation from being inst= rumented") Reported-by: Dan Carpenter Signed-off-by: Borislav Petkov Reviewed-by: Tony Luck Link: https://lore.kernel.org/r/20211217102029.GA29708@kili --- arch/x86/kernel/cpu/mce/severity.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/arch/x86/kernel/cpu/mce/severity.c b/arch/x86/kernel/cpu/mce/s= everity.c index a326467..7aa2bda 100644 --- a/arch/x86/kernel/cpu/mce/severity.c +++ b/arch/x86/kernel/cpu/mce/severity.c @@ -222,6 +222,9 @@ static bool is_copy_from_user(struct pt_regs *regs) struct insn insn; int ret; =20 + if (!regs) + return false; + if (copy_from_kernel_nofault(insn_buf, (void *)regs->ip, MAX_INSN_SIZE)) return false; =20 @@ -283,7 +286,7 @@ static noinstr int error_context(struct mce *m, struct = pt_regs *regs) switch (fixup_type) { case EX_TYPE_UACCESS: case EX_TYPE_COPY: - if (!regs || !copy_user) + if (!copy_user) return IN_KERNEL; m->kflags |=3D MCE_IN_KERNEL_COPYIN; fallthrough;