From patchwork Tue Apr 28 18:24:38 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "gregkh@linuxfoundation.org" X-Patchwork-Id: 226834 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=unavailable 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 C9A39C83004 for ; Tue, 28 Apr 2020 18:47:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A615920575 for ; Tue, 28 Apr 2020 18:47:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588099654; bh=vpnBgYOMkZl24zZAF+Gw4N8jzNY5K3OYGZBkJNrDpe0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=fHldiegunPYtGu4zZL+il1G6+mSF/KFuEWm49KdGgm8YGGYJBTsBUQa113Cpk2n3w 0cIg+gEZbVM4Xk4HPHnyu5hGw7x8v+88tJEqSn0YD5B5JvaPOHIrNpK+neGC9jChwe 3fMZVqoE18ivasdACCuwG3I6qm2AwoTUPGzmfRGI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731067AbgD1SmD (ORCPT ); Tue, 28 Apr 2020 14:42:03 -0400 Received: from mail.kernel.org ([198.145.29.99]:33728 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731063AbgD1SmD (ORCPT ); Tue, 28 Apr 2020 14:42:03 -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 F078720730; Tue, 28 Apr 2020 18:42:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588099322; bh=vpnBgYOMkZl24zZAF+Gw4N8jzNY5K3OYGZBkJNrDpe0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Xt8FWRCwt6aFA4n7r1jrvPA7+nFPgdWsZywDCmG5AupAWvzDMblxL1U23Gv66H0AV 3r190TCr4tihq4tR/2IW2YIO9YlV5tqn1bxxJUK7bXGy8RhBqkdSEvZwnh5lrsGuaY rM+DSbDI7nQ/s0CkDDDTNG7YHDvskV7v6HXrkeiE= 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 5.4 104/168] coredump: fix null pointer dereference on coredump Date: Tue, 28 Apr 2020 20:24:38 +0200 Message-Id: <20200428182245.549168975@linuxfoundation.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200428182231.704304409@linuxfoundation.org> References: <20200428182231.704304409@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@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