aboutsummaryrefslogtreecommitdiffstats
path: root/net/dccp
diff options
context:
space:
mode:
authorEric Dumazet <edumazet@google.com>2015-10-30 09:46:12 -0700
committerDavid S. Miller <davem@davemloft.net>2015-11-02 15:38:26 -0500
commitce1050089c969b96c797118f9cb0cf5a421ddc69 (patch)
tree96cae05caf0bddb2f7b3646efcabff06926cb13e /net/dccp
parentRDS: convert bind hash table to re-sizable hashtable (diff)
downloadlinux-dev-ce1050089c969b96c797118f9cb0cf5a421ddc69.tar.xz
linux-dev-ce1050089c969b96c797118f9cb0cf5a421ddc69.zip
tcp/dccp: fix ireq->pktopts race
IPv6 request sockets store a pointer to skb containing the SYN packet to be able to transfer it to full blown socket when 3WHS is done (ireq->pktopts -> np->pktoptions) As explained in commit 5e0724d027f0 ("tcp/dccp: fix hashdance race for passive sessions"), we must transfer the skb only if we won the hashdance race, if multiple cpus receive the 'ack' packet completing 3WHS at the same time. Fixes: e994b2f0fb92 ("tcp: do not lock listener to process SYN packets") Fixes: 079096f103fa ("tcp/dccp: install syn_recv requests into ehash table") Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/dccp')
-rw-r--r--net/dccp/ipv6.c16
1 files changed, 8 insertions, 8 deletions
diff --git a/net/dccp/ipv6.c b/net/dccp/ipv6.c
index ef4e48ce9143..db5fc2440a23 100644
--- a/net/dccp/ipv6.c
+++ b/net/dccp/ipv6.c
@@ -477,15 +477,7 @@ static struct sock *dccp_v6_request_recv_sock(const struct sock *sk,
/* Clone RX bits */
newnp->rxopt.all = np->rxopt.all;
- /* Clone pktoptions received with SYN */
newnp->pktoptions = NULL;
- if (ireq->pktopts != NULL) {
- newnp->pktoptions = skb_clone(ireq->pktopts, GFP_ATOMIC);
- consume_skb(ireq->pktopts);
- ireq->pktopts = NULL;
- if (newnp->pktoptions)
- skb_set_owner_r(newnp->pktoptions, newsk);
- }
newnp->opt = NULL;
newnp->mcast_oif = inet6_iif(skb);
newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
@@ -515,6 +507,14 @@ static struct sock *dccp_v6_request_recv_sock(const struct sock *sk,
goto out;
}
*own_req = inet_ehash_nolisten(newsk, req_to_sk(req_unhash));
+ /* Clone pktoptions received with SYN, if we own the req */
+ if (*own_req && ireq->pktopts) {
+ newnp->pktoptions = skb_clone(ireq->pktopts, GFP_ATOMIC);
+ consume_skb(ireq->pktopts);
+ ireq->pktopts = NULL;
+ if (newnp->pktoptions)
+ skb_set_owner_r(newnp->pktoptions, newsk);
+ }
return newsk;