From patchwork Tue Apr 21 01:14:20 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrew Morton X-Patchwork-Id: 227380 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=-3.8 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 autolearn=no 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 6C0C9C54FCC for ; Tue, 21 Apr 2020 01:14:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 40FF6214AF for ; Tue, 21 Apr 2020 01:14:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587431662; bh=POEvJdt69gGHvAgZYMOBFNyiIXP6vxMXEMUcWRPFzFY=; h=Date:From:To:Subject:In-Reply-To:List-ID:From; b=nmBOk5LxOreNq42zIFTl0IglMX0P8ksC3NYSL7D01y59lO6JSEHqP51LOV9hRXuU1 yOJZKNN1K4Lfc34eNUDSX47XIm6g1zxcjzp1+h8OfmiqAGuDKfTom+HRYO8aHrnDlq gUBPg0XdnqG4dyVlP6RDbZ1sOycj6Y2NHbY+QLJE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726161AbgDUBOV (ORCPT ); Mon, 20 Apr 2020 21:14:21 -0400 Received: from mail.kernel.org ([198.145.29.99]:35892 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726109AbgDUBOV (ORCPT ); Mon, 20 Apr 2020 21:14:21 -0400 Received: from localhost.localdomain (c-73-231-172-41.hsd1.ca.comcast.net [73.231.172.41]) (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 0A8142070B; Tue, 21 Apr 2020 01:14:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587431661; bh=POEvJdt69gGHvAgZYMOBFNyiIXP6vxMXEMUcWRPFzFY=; h=Date:From:To:Subject:In-Reply-To:From; b=LpftIEp+Tyvxyzzzs0DUvlX2i5LW9MKTICmE6CaFccckP/BjS30QmSGpdJh9l3aBw cAbgHMNsmdN6GEfAxkgTV/vc3mGlrtOFxQ5go86h5DCHxXh+kMxJ0E/LItA2rbzuNp QV30MFGmvLRBVMEibvfk/EsMZ2ExXmT8y9VuATxA= Date: Mon, 20 Apr 2020 18:14:20 -0700 From: Andrew Morton To: akpm@linux-foundation.org, linux-mm@kvack.org, matthew.ruffell@canonical.com, mm-commits@vger.kernel.org, nhorman@tuxdriver.com, pabs3@bonedaddy.net, stable@vger.kernel.org, sudipm.mukherjee@gmail.com, torvalds@linux-foundation.org, viro@zeniv.linux.org.uk Subject: [patch 14/15] coredump: fix null pointer dereference on coredump Message-ID: <20200421011420.GnVj8rZfk%akpm@linux-foundation.org> In-Reply-To: <20200420181310.c18b3c0aa4dc5b3e5ec1be10@linux-foundation.org> User-Agent: s-nail v14.8.16 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Sudip Mukherjee Subject: coredump: fix null pointer dereference on coredump 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: [ 108.212680] RIP: 0010: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: [ 48.453756] format_corename failed [ 48.453758] Aborting core Link: http://lkml.kernel.org/r/20200416194612.21418-1-sudipm.mukherjee@gmail.com Fixes: 315c69261dd3 ("coredump: split pipe command whitespace before expanding template") Signed-off-by: Sudip Mukherjee Reported-by: Matthew Ruffell Cc: Paul Wise Cc: Alexander Viro Cc: Neil Horman Cc: Signed-off-by: Andrew Morton --- fs/coredump.c | 2 ++ 1 file changed, 2 insertions(+) --- a/fs/coredump.c~coredump-fix-null-pointer-dereference-on-coredump +++ a/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