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=-2.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,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 50DABC07520 for ; Thu, 13 Sep 2018 13:38:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 10CEB20854 for ; Thu, 13 Sep 2018 13:38:01 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 10CEB20854 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 S1729414AbeIMSr3 (ORCPT ); Thu, 13 Sep 2018 14:47:29 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:59618 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726967AbeIMSr2 (ORCPT ); Thu, 13 Sep 2018 14:47:28 -0400 Received: from localhost (ip-213-127-77-73.ip.prioritytelecom.net [213.127.77.73]) by mail.linuxfoundation.org (Postfix) with ESMTPSA id 7C433CF3; Thu, 13 Sep 2018 13:37:57 +0000 (UTC) From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Michal Suchanek , Mahesh Salgaonkar , Michael Ellerman , Sasha Levin Subject: [PATCH 4.9 51/78] powerpc/pseries: Avoid using the size greater than RTAS_ERROR_LOG_MAX. Date: Thu, 13 Sep 2018 15:31:38 +0200 Message-Id: <20180913131810.904525110@linuxfoundation.org> X-Mailer: git-send-email 2.19.0 In-Reply-To: <20180913131805.732342940@linuxfoundation.org> References: <20180913131805.732342940@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 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Mahesh Salgaonkar [ Upstream commit 74e96bf44f430cf7a01de19ba6cf49b361cdfd6e ] The global mce data buffer that used to copy rtas error log is of 2048 (RTAS_ERROR_LOG_MAX) bytes in size. Before the copy we read extended_log_length from rtas error log header, then use max of extended_log_length and RTAS_ERROR_LOG_MAX as a size of data to be copied. Ideally the platform (phyp) will never send extended error log with size > 2048. But if that happens, then we have a risk of buffer overrun and corruption. Fix this by using min_t instead. Fixes: d368514c3097 ("powerpc: Fix corruption when grabbing FWNMI data") Reported-by: Michal Suchanek Signed-off-by: Mahesh Salgaonkar Signed-off-by: Michael Ellerman Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- arch/powerpc/platforms/pseries/ras.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/arch/powerpc/platforms/pseries/ras.c +++ b/arch/powerpc/platforms/pseries/ras.c @@ -357,7 +357,7 @@ static struct rtas_error_log *fwnmi_get_ int len, error_log_length; error_log_length = 8 + rtas_error_extended_log_length(h); - len = max_t(int, error_log_length, RTAS_ERROR_LOG_MAX); + len = min_t(int, error_log_length, RTAS_ERROR_LOG_MAX); memset(global_mce_data_buf, 0, RTAS_ERROR_LOG_MAX); memcpy(global_mce_data_buf, h, len); errhdr = (struct rtas_error_log *)global_mce_data_buf;