tcp/dccp: remove obsolete WARN_ON() in icmp handlers

Now SYN_RECV request sockets are installed in ehash table, an ICMP
handler can find a request socket while another cpu handles an incoming
packet transforming this SYN_RECV request socket into an ESTABLISHED
socket.

We need to remove the now obsolete WARN_ON(req->sk), since req->sk
is set when a new child is created and added into listener accept queue.

If this race happens, the ICMP will do nothing special.

Fixes: 079096f103fa ("tcp/dccp: install syn_recv requests into ehash table")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Ben Lazarus <blazarus@google.com>
Reported-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 0 insertions, 2 deletions

diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 0b02ef773705..e7528b101e68 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -319,8 +319,6 @@ void tcp_req_err(struct sock *sk, u32 seq, bool abort)
         /* ICMPs are not backlogged, hence we cannot get
          * an established socket here.
          */
-        WARN_ON(req->sk);
-
         if (seq != tcp_rsk(req)->snt_isn) {
                 NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
         } else if (abort) {