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=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED 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 752DDC0044C for ; Mon, 5 Nov 2018 11:00:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DC4F820827 for ; Mon, 5 Nov 2018 11:00:54 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DC4F820827 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.com 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 S1729122AbeKEUUB (ORCPT ); Mon, 5 Nov 2018 15:20:01 -0500 Received: from mx2.suse.de ([195.135.220.15]:51004 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727275AbeKEUUB (ORCPT ); Mon, 5 Nov 2018 15:20:01 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay1.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 33FB2AF8D; Mon, 5 Nov 2018 11:00:51 +0000 (UTC) From: Luis Henriques To: "Yan, Zheng" , Sage Weil , Ilya Dryomov Cc: Dan Carpenter , ceph-devel@vger.kernel.org, linux-kernel@vger.kernel.org, Luis Henriques Subject: [PATCH] ceph: quota: fix null pointer dereference in quota check Date: Mon, 5 Nov 2018 11:00:52 +0000 Message-Id: <20181105110052.31759-1-lhenriques@suse.com> In-Reply-To: <20181101065318.2cylxol6d444nzeu@kili.mountain> References: <20181101065318.2cylxol6d444nzeu@kili.mountain> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This patch fixes a possible null pointer dereference in check_quota_exceeded, detected by the static checker smatch, with the following warning: fs/ceph/quota.c:240 check_quota_exceeded() error: we previously assumed 'realm' could be null (see line 188) Reported-by: Dan Carpenter Link: https://lkml.kernel.org/n/20181101065318.2cylxol6d444nzeu@kili.mountain Fixes: b7a2921765cf ("ceph: quota: support for ceph.quota.max_files") Signed-off-by: Luis Henriques --- fs/ceph/quota.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/ceph/quota.c b/fs/ceph/quota.c index 32d4f13784ba..03f4d24db8fe 100644 --- a/fs/ceph/quota.c +++ b/fs/ceph/quota.c @@ -237,7 +237,8 @@ static bool check_quota_exceeded(struct inode *inode, enum quota_check_op op, ceph_put_snap_realm(mdsc, realm); realm = next; } - ceph_put_snap_realm(mdsc, realm); + if (realm) + ceph_put_snap_realm(mdsc, realm); up_read(&mdsc->snap_rwsem); return exceeded;