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=-5.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 A65B9ECE561 for ; Mon, 24 Sep 2018 12:31:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6A03421486 for ; Mon, 24 Sep 2018 12:31:15 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6A03421486 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387995AbeIXSdH (ORCPT ); Mon, 24 Sep 2018 14:33:07 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:57936 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730258AbeIXSdH (ORCPT ); Mon, 24 Sep 2018 14:33:07 -0400 Received: from localhost (ip-213-127-77-73.ip.prioritytelecom.net [213.127.77.73]) by mail.linuxfoundation.org (Postfix) with ESMTPSA id EC8DC1098; Mon, 24 Sep 2018 12:31:11 +0000 (UTC) From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Mark Rutland , Catalin Marinas , Will Deacon , Sasha Levin Subject: [PATCH 4.18 073/235] arm64: fix possible spectre-v1 write in ptrace_hbp_set_event() Date: Mon, 24 Sep 2018 13:50:59 +0200 Message-Id: <20180924113112.513448138@linuxfoundation.org> X-Mailer: git-send-email 2.19.0 In-Reply-To: <20180924113103.999624566@linuxfoundation.org> References: <20180924113103.999624566@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Mark Rutland [ Upstream commit 14d6e289a89780377f8bb09de8926d3c62d763cd ] It's possible for userspace to control idx. Sanitize idx when using it as an array index, to inhibit the potential spectre-v1 write gadget. Found by smatch. Signed-off-by: Mark Rutland Cc: Catalin Marinas Cc: Will Deacon Signed-off-by: Will Deacon Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- arch/arm64/kernel/ptrace.c | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-) --- a/arch/arm64/kernel/ptrace.c +++ b/arch/arm64/kernel/ptrace.c @@ -277,19 +277,22 @@ static int ptrace_hbp_set_event(unsigned switch (note_type) { case NT_ARM_HW_BREAK: - if (idx < ARM_MAX_BRP) { - tsk->thread.debug.hbp_break[idx] = bp; - err = 0; - } + if (idx >= ARM_MAX_BRP) + goto out; + idx = array_index_nospec(idx, ARM_MAX_BRP); + tsk->thread.debug.hbp_break[idx] = bp; + err = 0; break; case NT_ARM_HW_WATCH: - if (idx < ARM_MAX_WRP) { - tsk->thread.debug.hbp_watch[idx] = bp; - err = 0; - } + if (idx >= ARM_MAX_WRP) + goto out; + idx = array_index_nospec(idx, ARM_MAX_WRP); + tsk->thread.debug.hbp_watch[idx] = bp; + err = 0; break; } +out: return err; }