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=-3.0 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 C2721C4646D for ; Sat, 4 Aug 2018 09:04:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 76D7C217BF for ; Sat, 4 Aug 2018 09:04:13 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 76D7C217BF 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 S1732551AbeHDLEI (ORCPT ); Sat, 4 Aug 2018 07:04:08 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:48512 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726983AbeHDLEH (ORCPT ); Sat, 4 Aug 2018 07:04:07 -0400 Received: from localhost (D57E6652.static.ziggozakelijk.nl [213.126.102.82]) by mail.linuxfoundation.org (Postfix) with ESMTPSA id 9548889C; Sat, 4 Aug 2018 09:04:09 +0000 (UTC) From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Yi Wang , Jiang Biao , Richard Guy Briggs , Paul Moore Subject: [PATCH 4.14 17/23] audit: fix potential null dereference context->module.name Date: Sat, 4 Aug 2018 11:01:08 +0200 Message-Id: <20180804082645.583152736@linuxfoundation.org> X-Mailer: git-send-email 2.18.0 In-Reply-To: <20180804082643.641435547@linuxfoundation.org> References: <20180804082643.641435547@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Yi Wang commit b305f7ed0f4f494ad6f3ef5667501535d5a8fa31 upstream. The variable 'context->module.name' may be null pointer when kmalloc return null, so it's better to check it before using to avoid null dereference. Another one more thing this patch does is using kstrdup instead of (kmalloc + strcpy), and signal a lost record via audit_log_lost. Cc: stable@vger.kernel.org # 4.11 Signed-off-by: Yi Wang Reviewed-by: Jiang Biao Reviewed-by: Richard Guy Briggs Signed-off-by: Paul Moore Signed-off-by: Greg Kroah-Hartman --- kernel/auditsc.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) --- a/kernel/auditsc.c +++ b/kernel/auditsc.c @@ -1274,8 +1274,12 @@ static void show_special(struct audit_co break; case AUDIT_KERN_MODULE: audit_log_format(ab, "name="); - audit_log_untrustedstring(ab, context->module.name); - kfree(context->module.name); + if (context->module.name) { + audit_log_untrustedstring(ab, context->module.name); + kfree(context->module.name); + } else + audit_log_format(ab, "(null)"); + break; } audit_log_end(ab); @@ -2387,8 +2391,9 @@ void __audit_log_kern_module(char *name) { struct audit_context *context = current->audit_context; - context->module.name = kmalloc(strlen(name) + 1, GFP_KERNEL); - strcpy(context->module.name, name); + context->module.name = kstrdup(name, GFP_KERNEL); + if (!context->module.name) + audit_log_lost("out of memory in __audit_log_kern_module"); context->type = AUDIT_KERN_MODULE; }