Commit a20ea298 authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

sctp: read sk->sk_bound_dev_if once in sctp_rcv() 



sctp_rcv() reads sk->sk_bound_dev_if twice while the socket
is not locked. Another cpu could change this field under us.

Fixes: 0fd9a65a ("[SCTP] Support SO_BINDTODEVICE socket option on incoming packets.")
Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Cc: Neil Horman <nhorman@tuxdriver.com>
Cc: Vlad Yasevich <vyasevich@gmail.com>
Cc: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Acked-by: default avatarMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 4c971d2f

net/sctp/input.c

+3 −1
Original line number Diff line number Diff line
@@ -92,6 +92,7 @@ int sctp_rcv(struct sk_buff *skb) 
	struct sctp_chunk *chunk;

	union sctp_addr src;

	union sctp_addr dest;

	int bound_dev_if;

	int family;

	struct sctp_af *af;

	struct net *net = dev_net(skb->dev);
@@ -169,7 +170,8 @@ int sctp_rcv(struct sk_buff *skb) 
	 * If a frame arrives on an interface and the receiving socket is

	 * bound to another interface, via SO_BINDTODEVICE, treat it as OOTB

	 */

	if (sk->sk_bound_dev_if && (sk->sk_bound_dev_if != af->skb_iif(skb))) {

	bound_dev_if = READ_ONCE(sk->sk_bound_dev_if);

	if (bound_dev_if && (bound_dev_if != af->skb_iif(skb))) {

		if (transport) {

			sctp_transport_put(transport);

			asoc = NULL;