diff options
| author | Eric Dumazet <eric.dumazet@gmail.com> | 2011-11-01 16:56:59 +0400 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2011-11-02 08:51:27 +0400 |
| commit | 0ad92ad03aa444b312bd318b0341011a8be09d13 (patch) | |
| tree | a6acc6651c301af1a5c7edd4258a441da091bfd3 /net | |
| parent | 501e89d3aef10f9a5b79137fbb0bcd5bf9cac2ac (diff) | |
| download | linux-0ad92ad03aa444b312bd318b0341011a8be09d13.tar.xz | |
udp: fix a race in encap_rcv handling
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>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
| -rw-r--r-- | net/ipv4/udp.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c index 131d8a720086..ab0966df1e2a 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, |