Commit 0398ba9e authored Dec 07, 2020 by Cengiz Can Committed by David S. Miller Dec 08, 2020

net: tipc: prevent possible null deref of link



`tipc_node_apply_property` does a null check on a `tipc_link_entry`
pointer but also accesses the same pointer out of the null check block.

This triggers a warning on Coverity Static Analyzer because we're
implying that `e->link` can BE null.

Move "Update MTU for node link entry" line into if block to make sure
that we're not in a state that `e->link` is null.

Signed-off-by: Cengiz Can <cengiz@kernel.wtf>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 9756bb63

net/tipc/node.c

+4 −2

Original line number	Diff line number	Diff line
		@@ -2181,9 +2181,11 @@ void tipc_node_apply_property(struct net net, struct tipc_bearer b,
		&xmitq);
		else if (prop == TIPC_NLA_PROP_MTU)
		tipc_link_set_mtu(e->link, b->mtu);
		}

		/* Update MTU for node link entry */
		e->mtu = tipc_link_mss(e->link);
		}

		tipc_node_write_unlock(n);
		tipc_bearer_xmit(net, bearer_id, &xmitq, &e->maddr, NULL);
		}