From 805c4bc05705fb2b71ec970960b456eee9900953 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Thu, 5 Nov 2015 11:07:13 -0800 Subject: 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 Reported-by: Ying Cai Signed-off-by: David S. Miller --- net/ipv4/tcp_ipv4.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'net/ipv4/tcp_ipv4.c') diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index 1c2648bbac4b..59aff63b1776 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; -- cgit v1.2.3 From 49a496c97d035f2eab7cef4894dd46202184fc81 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Thu, 5 Nov 2015 12:50:19 -0800 Subject: tcp: use correct req pointer in tcp_move_syn() calls I mistakenly took wrong request sock pointer when calling tcp_move_syn() @req_unhash is either a copy of @req, or a NULL value for FastOpen connexions (as we do not expect to unhash the temporary request sock from ehash table) Fixes: 805c4bc05705 ("tcp: fix req->saved_syn race") Signed-off-by: Eric Dumazet Cc: Ying Cai Signed-off-by: David S. Miller --- net/ipv4/tcp_ipv4.c | 2 +- net/ipv6/tcp_ipv6.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) (limited to 'net/ipv4/tcp_ipv4.c') diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index 59aff63b1776..950e28c0cdf2 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -1327,7 +1327,7 @@ struct sock *tcp_v4_syn_recv_sock(const struct sock *sk, struct sk_buff *skb, goto put_and_exit; *own_req = inet_ehash_nolisten(newsk, req_to_sk(req_unhash)); if (*own_req) - tcp_move_syn(newtp, req_unhash); + tcp_move_syn(newtp, req); return newsk; diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index c509e5562429..5baa8e754e41 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -1141,7 +1141,7 @@ static struct sock *tcp_v6_syn_recv_sock(const struct sock *sk, struct sk_buff * } *own_req = inet_ehash_nolisten(newsk, req_to_sk(req_unhash)); if (*own_req) { - tcp_move_syn(newtp, req_unhash); + tcp_move_syn(newtp, req); /* Clone pktoptions received with SYN, if we own the req */ if (ireq->pktopts) { -- cgit v1.2.3