diff options
| author | Eric Dumazet <edumazet@google.com> | 2015-11-05 11:07:13 -0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2015-11-05 14:36:09 -0500 |
| commit | 805c4bc05705fb2b71ec970960b456eee9900953 (patch) | |
| tree | 6e753b369a8f3663b5a50d3174b1a6fe0495714f | |
| parent | 428ad1bc6dd766bb44171bba43a8a3219be77d2e (diff) | |
| download | op-kernel-dev-805c4bc05705fb2b71ec970960b456eee9900953.zip op-kernel-dev-805c4bc05705fb2b71ec970960b456eee9900953.tar.gz | |
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>
| -rw-r--r-- | include/linux/tcp.h | 7 | ||||
| -rw-r--r-- | net/ipv4/tcp_ipv4.c | 2 | ||||
| -rw-r--r-- | net/ipv4/tcp_minisocks.c | 3 | ||||
| -rw-r--r-- | net/ipv6/tcp_ipv6.c | 20 |
4 files changed, 21 insertions, 11 deletions
diff --git a/include/linux/tcp.h b/include/linux/tcp.h index c906f45..b386361 100644 --- a/include/linux/tcp.h +++ b/include/linux/tcp.h @@ -397,6 +397,13 @@ static inline void fastopen_queue_tune(struct sock *sk, int backlog) queue->fastopenq.max_qlen = min_t(unsigned int, backlog, somaxconn); } +static inline void tcp_move_syn(struct tcp_sock *tp, + struct request_sock *req) +{ + tp->saved_syn = req->saved_syn; + req->saved_syn = NULL; +} + static inline void tcp_saved_syn_free(struct tcp_sock *tp) { kfree(tp->saved_syn); diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index 1c2648b..59aff63 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -1326,6 +1326,8 @@ struct sock *tcp_v4_syn_recv_sock(const struct sock *sk, struct sk_buff *skb, if (__inet_inherit_port(sk, newsk) < 0) goto put_and_exit; *own_req = inet_ehash_nolisten(newsk, req_to_sk(req_unhash)); + if (*own_req) + tcp_move_syn(newtp, req_unhash); return newsk; diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c index 3575dd1..ac6b196 100644 --- a/net/ipv4/tcp_minisocks.c +++ b/net/ipv4/tcp_minisocks.c @@ -551,9 +551,6 @@ struct sock *tcp_create_openreq_child(const struct sock *sk, newtp->rack.mstamp.v64 = 0; newtp->rack.advanced = 0; - newtp->saved_syn = req->saved_syn; - req->saved_syn = NULL; - TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_PASSIVEOPENS); } return newsk; 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 @@ static struct sock *tcp_v6_syn_recv_sock(const struct sock *sk, struct sk_buff * 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; |
