ceph: quota: fix null pointer dereference in quota check

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: b7a2921765 ("ceph: quota: support for ceph.quota.max_files")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Luis Henriques <lhenriques@suse.com>
Reviewed-by: "Yan, Zheng" <zyan@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
This commit is contained in:
Luis Henriques 2018-11-05 19:00:52 +00:00 committed by Ilya Dryomov
parent c2c6d3ce0d
commit 71f2cc64d0

View File

@ -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;