tipc: Discard incoming broadcast messages that are unexpected (9f6bdcd4) · Commits · 戴 / test

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>

net/tipc/bcast.c

+11 −2

Original line number	Diff line number	Diff line
		@@ -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);
		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);

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