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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, 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 C4F5EC4BA24 for ; Wed, 26 Feb 2020 23:43:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A0A6A20801 for ; Wed, 26 Feb 2020 23:43:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727992AbgBZXn0 (ORCPT ); Wed, 26 Feb 2020 18:43:26 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:35935 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727935AbgBZXn0 (ORCPT ); Wed, 26 Feb 2020 18:43:26 -0500 Received: from 1.general.cking.uk.vpn ([10.172.193.212] helo=localhost) by youngberry.canonical.com with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.86_2) (envelope-from ) id 1j76Kn-0006bS-6f; Wed, 26 Feb 2020 23:43:21 +0000 From: Colin King To: Trond Myklebust , Anna Schumaker , linux-nfs@vger.kernel.org Cc: kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] NFS: check for allocation failure from mempool_alloc Date: Wed, 26 Feb 2020 23:43:20 +0000 Message-Id: <20200226234320.7722-1-colin.king@canonical.com> X-Mailer: git-send-email 2.25.0 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: Colin Ian King It is possible for mempool_alloc to return null when using the GFP_KERNEL flag, so return NULL and avoid a null pointer dereference on the following memset of the null pointer. Addresses-Coverity: ("Dereference null return") Fixes: 2b17d725f9be ("NFS: Clean up writeback code") Signed-off-by: Colin Ian King --- fs/nfs/write.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/fs/nfs/write.c b/fs/nfs/write.c index c478b772cc49..7ca036660dd1 100644 --- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -106,6 +106,9 @@ static struct nfs_pgio_header *nfs_writehdr_alloc(void) { struct nfs_pgio_header *p = mempool_alloc(nfs_wdata_mempool, GFP_KERNEL); + if (!p) + return NULL; + memset(p, 0, sizeof(*p)); p->rw_mode = FMODE_WRITE; return p; -- 2.25.0