Commit cd26da4f authored Oct 31, 2016 by Xin Long Committed by David S. Miller Oct 31, 2016

sctp: hold transport instead of assoc in sctp_diag

In sctp_transport_lookup_process(), Commit 1cceda78 ("sctp: fix
the issue sctp_diag uses lock_sock in rcu_read_lock") moved cb() out
of rcu lock, but it put transport and hold assoc instead, and ignore
that cb() still uses transport. It may cause a use-after-free issue.

This patch is to hold transport instead of assoc there.

Fixes: 1cceda78 ("sctp: fix the issue sctp_diag uses lock_sock in rcu_read_lock")
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 87557efc

net/sctp/socket.c

+1 −4

Original line number	Diff line number	Diff line
		@@ -4480,12 +4480,9 @@ int sctp_transport_lookup_process(int (cb)(struct sctp_transport , void *),
		if (!transport \|\| !sctp_transport_hold(transport))
		goto out;

		sctp_association_hold(transport->asoc);
		sctp_transport_put(transport);

		rcu_read_unlock();
		err = cb(transport, p);
		sctp_association_put(transport->asoc);
		sctp_transport_put(transport);

		out:
		return err;