tcp: fix req->saved_syn race
For the reasons explained in commit ce1050089c96 ("tcp/dccp: fix
ireq->pktopts race"), we need to make sure we do not access
req->saved_syn unless we own the request sock.
This fixes races for listeners using TCP_SAVE_SYN option.
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>
Reported-by: Ying Cai <ycai@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index ea2f4d5..c509e55 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -1140,14 +1140,18 @@
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,
- sk_gfp_atomic(sk, GFP_ATOMIC));
- consume_skb(ireq->pktopts);
- ireq->pktopts = NULL;
- if (newnp->pktoptions)
- skb_set_owner_r(newnp->pktoptions, newsk);
+ if (*own_req) {
+ tcp_move_syn(newtp, req_unhash);
+
+ /* Clone pktoptions received with SYN, if we own the req */
+ if (ireq->pktopts) {
+ newnp->pktoptions = skb_clone(ireq->pktopts,
+ sk_gfp_atomic(sk, GFP_ATOMIC));
+ consume_skb(ireq->pktopts);
+ ireq->pktopts = NULL;
+ if (newnp->pktoptions)
+ skb_set_owner_r(newnp->pktoptions, newsk);
+ }
}
return newsk;