ceph: don't drop message if it contains more data than expected
Later version mds may encode more data into messages.
Signed-off-by: "Yan, Zheng" <zyan@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
index 5b767cf..bc43c82 100644
--- a/fs/ceph/mds_client.c
+++ b/fs/ceph/mds_client.c
@@ -3406,10 +3406,10 @@ static void handle_lease(struct ceph_mds_client *mdsc,
vino.ino = le64_to_cpu(h->ino);
vino.snap = CEPH_NOSNAP;
seq = le32_to_cpu(h->seq);
- dname.name = (void *)h + sizeof(*h) + sizeof(u32);
- dname.len = msg->front.iov_len - sizeof(*h) - sizeof(u32);
- if (dname.len != get_unaligned_le32(h+1))
+ dname.len = get_unaligned_le32(h + 1);
+ if (msg->front.iov_len < sizeof(*h) + sizeof(u32) + dname.len)
goto bad;
+ dname.name = (void *)(h + 1) + sizeof(u32);
/* lookup inode */
inode = ceph_find_inode(sb, vino);