diff options
author | Eric Dumazet <eric.dumazet@gmail.com> | 2011-11-01 08:56:59 -0400 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2011-11-02 00:51:27 -0400 |
commit | 0ad92ad03aa444b312bd318b0341011a8be09d13 (patch) | |
tree | a6acc6651c301af1a5c7edd4258a441da091bfd3 /net/ipv4/udp.c | |
parent | 501e89d3aef10f9a5b79137fbb0bcd5bf9cac2ac (diff) |
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/ipv4/udp.c')
-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) | |||
1397 | nf_reset(skb); | 1397 | nf_reset(skb); |
1398 | 1398 | ||
1399 | if (up->encap_type) { | 1399 | if (up->encap_type) { |
1400 | int (*encap_rcv)(struct sock *sk, struct sk_buff *skb); | ||
1401 | |||
1400 | /* | 1402 | /* |
1401 | * This is an encapsulation socket so pass the skb to | 1403 | * This is an encapsulation socket so pass the skb to |
1402 | * the socket's udp_encap_rcv() hook. Otherwise, just | 1404 | * 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) | |||
1409 | */ | 1411 | */ |
1410 | 1412 | ||
1411 | /* if we're overly short, let UDP handle it */ | 1413 | /* if we're overly short, let UDP handle it */ |
1412 | if (skb->len > sizeof(struct udphdr) && | 1414 | encap_rcv = ACCESS_ONCE(up->encap_rcv); |
1413 | up->encap_rcv != NULL) { | 1415 | if (skb->len > sizeof(struct udphdr) && encap_rcv != NULL) { |
1414 | int ret; | 1416 | int ret; |
1415 | 1417 | ||
1416 | ret = (*up->encap_rcv)(sk, skb); | 1418 | ret = encap_rcv(sk, skb); |
1417 | if (ret <= 0) { | 1419 | if (ret <= 0) { |
1418 | UDP_INC_STATS_BH(sock_net(sk), | 1420 | UDP_INC_STATS_BH(sock_net(sk), |
1419 | UDP_MIB_INDATAGRAMS, | 1421 | UDP_MIB_INDATAGRAMS, |