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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,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 2836BC83004 for ; Tue, 28 Apr 2020 18:56:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EF7AF206A1 for ; Tue, 28 Apr 2020 18:56:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588100183; bh=vpnBgYOMkZl24zZAF+Gw4N8jzNY5K3OYGZBkJNrDpe0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=V+73Pq0Srw0FVen5c35qokaohfMMjksEyACdMAwvd5+smivzNpjEIZokqsOP7DY4R hBDHrMUWZWZAuQayrs6bPBcxdbOsl8aWxJjUCZNycfygxz0kzrLoeTLTd7BIXew02P yu5NnzQ/dIV0apxFJ2pP18xjvTXT7QpDW6tg95zQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729689AbgD1Sbf (ORCPT ); Tue, 28 Apr 2020 14:31:35 -0400 Received: from mail.kernel.org ([198.145.29.99]:47104 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729182AbgD1Sba (ORCPT ); Tue, 28 Apr 2020 14:31:30 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id D93A42186A; Tue, 28 Apr 2020 18:31:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588098690; bh=vpnBgYOMkZl24zZAF+Gw4N8jzNY5K3OYGZBkJNrDpe0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=iIO335iqsjWcbbdtLSEIUIuCtuYyDKbEcPa+rVCJeZxV8rczGtLLsY9I02ryqLTia 3bf4FOefCnLrjSLCzyhwSRTRJOWtMG0ecb1mDyAGYvPjl2hzogopK7zOUi/mPgtRdm 4smG5jnP36pwnkvh8AXUEtzF2vd6An8sRKKIr8NI= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Matthew Ruffell , Sudip Mukherjee , Andrew Morton , Paul Wise , Alexander Viro , Neil Horman , Linus Torvalds Subject: [PATCH 5.6 099/167] coredump: fix null pointer dereference on coredump Date: Tue, 28 Apr 2020 20:24:35 +0200 Message-Id: <20200428182237.696357713@linuxfoundation.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200428182225.451225420@linuxfoundation.org> References: <20200428182225.451225420@linuxfoundation.org> User-Agent: quilt/0.66 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 From: Sudip Mukherjee commit db973a7289dad24e6c017dcedc6aee886579dc3a upstream. If the core_pattern is set to "|" and any process segfaults then we get a null pointer derefernce while trying to coredump. The call stack shows: RIP: do_coredump+0x628/0x11c0 When the core_pattern has only "|" there is no use of trying the coredump and we can check that while formating the corename and exit with an error. After this change I get: format_corename failed Aborting core Fixes: 315c69261dd3 ("coredump: split pipe command whitespace before expanding template") Reported-by: Matthew Ruffell Signed-off-by: Sudip Mukherjee Signed-off-by: Andrew Morton Cc: Paul Wise Cc: Alexander Viro Cc: Neil Horman Cc: Link: http://lkml.kernel.org/r/20200416194612.21418-1-sudipm.mukherjee@gmail.com Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- fs/coredump.c | 2 ++ 1 file changed, 2 insertions(+) --- a/fs/coredump.c +++ b/fs/coredump.c @@ -211,6 +211,8 @@ static int format_corename(struct core_n return -ENOMEM; (*argv)[(*argc)++] = 0; ++pat_ptr; + if (!(*pat_ptr)) + return -ENOMEM; } /* Repeat as long as we have more pattern to process and more output