| Message ID | 1320188219.4728.7.camel@edumazet-laptop |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
From: Eric Dumazet <eric.dumazet@gmail.com> Date: Tue, 01 Nov 2011 23:56:59 +0100 > udp_queue_rcv_skb() has a possible race in encap_rcv handling, since > this pointer can be changed anytime. > > We should use ACCESS_ONCE() to close the race. > > Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Applied and queued up for -stable, thanks! -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c index ebaa96b..15b50df 100644 --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -1397,6 +1397,8 @@ int udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) nf_reset(skb); if (up->encap_type) { + int (*encap_rcv)(struct sock *sk, struct sk_buff *skb); + /* * This is an encapsulation socket so pass the skb to * the socket's udp_encap_rcv() hook. Otherwise, just @@ -1409,11 +1411,11 @@ int udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) */ /* if we're overly short, let UDP handle it */ - if (skb->len > sizeof(struct udphdr) && - up->encap_rcv != NULL) { + encap_rcv = ACCESS_ONCE(up->encap_rcv); + if (skb->len > sizeof(struct udphdr) && encap_rcv != NULL) { int ret; - ret = (*up->encap_rcv)(sk, skb); + ret = encap_rcv(sk, skb); if (ret <= 0) { UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INDATAGRAMS,
udp_queue_rcv_skb() has a possible race in encap_rcv handling, since this pointer can be changed anytime. We should use ACCESS_ONCE() to close the race. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> --- net/ipv4/udp.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html