From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Sasha Levin To: stable@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Luis Henriques , Ilya Dryomov , Sasha Levin , ceph-devel@vger.kernel.org Subject: [PATCH AUTOSEL 4.18 35/59] ceph: quota: fix null pointer dereference in quota check Date: Wed, 14 Nov 2018 17:23:07 -0500 Message-Id: <20181114222335.99339-35-sashal@kernel.org> In-Reply-To: <20181114222335.99339-1-sashal@kernel.org> References: <20181114222335.99339-1-sashal@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit List-ID: From: Luis Henriques [ Upstream commit 71f2cc64d027d712f29bf8d09d3e123302d5f245 ] 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) Fixes: b7a2921765cf ("ceph: quota: support for ceph.quota.max_files") Reported-by: Dan Carpenter Signed-off-by: Luis Henriques Reviewed-by: "Yan, Zheng" Signed-off-by: Ilya Dryomov Signed-off-by: Sasha Levin --- 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 242bfa5c0539..47cc6f41d100 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; -- 2.17.1