libceph: skip message if too big to receive

We know the length of our message buffers.  If we get a message
that's too long, just dump it and ignore it.  If skip was set
then con->in_msg won't be valid, so be careful not to dereference
a null pointer in the process.

This resolves:
    http://tracker.ceph.com/issues/4664

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
This commit is contained in:
Alex Elder 2013-04-05 14:46:01 -05:00 committed by Sage Weil
parent ea96571f7b
commit f759ebb968

View File

@ -2207,10 +2207,18 @@ static int read_partial_message(struct ceph_connection *con)
ret = ceph_con_in_msg_alloc(con, &skip);
if (ret < 0)
return ret;
BUG_ON(!con->in_msg ^ skip);
if (con->in_msg && data_len > con->in_msg->data_length) {
pr_warning("%s skipping long message (%u > %zd)\n",
__func__, data_len, con->in_msg->data_length);
ceph_msg_put(con->in_msg);
con->in_msg = NULL;
skip = 1;
}
if (skip) {
/* skip this message */
dout("alloc_msg said skip message\n");
BUG_ON(con->in_msg);
con->in_base_pos = -front_len - middle_len - data_len -
sizeof(m->footer);
con->in_tag = CEPH_MSGR_TAG_READY;