tipc: Discard incoming broadcast messages that are unexpected

Modifies TIPC's incoming broadcast packet handler to discard messages
that cannot legally be sent over the broadcast link, including:

- broadcast protocol messages that do no contain state information
- payload messages that are not named multicast messages
- any other form of message except for bundled messages, fragmented
  messages, and name distribution messages.

These checks are needed to prevent TIPC from handing an unexpected
message to a routine that isn't prepared to handle it, which could
lead to incorrect processing (up to and including invalid memory
references caused by attempts to access message fields that aren't
present in the message).

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
This commit is contained in:
Allan Stephens 2011-04-07 14:57:53 -04:00 committed by Paul Gortmaker
parent 693d03ae3c
commit 9f6bdcd428

View File

@ -39,6 +39,7 @@
#include "link.h"
#include "port.h"
#include "bcast.h"
#include "name_distr.h"
#define MAX_PKT_DEFAULT_MCAST 1500 /* bcast link max packet size (fixed) */
@ -445,6 +446,8 @@ void tipc_bclink_recv_pkt(struct sk_buff *buf)
goto unlock;
if (unlikely(msg_user(msg) == BCAST_PROTOCOL)) {
if (msg_type(msg) != STATE_MSG)
goto unlock;
if (msg_destnode(msg) == tipc_own_addr) {
tipc_bclink_acknowledge(node, msg_bcast_ack(msg));
tipc_node_unlock(node);
@ -480,7 +483,10 @@ receive:
}
if (likely(msg_isdata(msg))) {
tipc_node_unlock(node);
tipc_port_recv_mcast(buf, NULL);
if (likely(msg_mcast(msg)))
tipc_port_recv_mcast(buf, NULL);
else
buf_discard(buf);
} else if (msg_user(msg) == MSG_BUNDLER) {
bcl->stats.recv_bundles++;
bcl->stats.recv_bundled += msg_msgcnt(msg);
@ -493,9 +499,12 @@ receive:
bcl->stats.recv_fragmented++;
tipc_node_unlock(node);
tipc_net_route_msg(buf);
} else if (msg_user(msg) == NAME_DISTRIBUTOR) {
tipc_node_unlock(node);
tipc_named_recv(buf);
} else {
tipc_node_unlock(node);
tipc_net_route_msg(buf);
buf_discard(buf);
}
buf = NULL;
tipc_node_lock(node);