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

[ Upstream commit e316ea62e3203d524ff0239a40c56d3a39ad1b5c ]

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/net/dccp/ipv4.c b/net/dccp/ipv4.c
index 902d606324a04ff81adbdc301a1ed58baa3f61f9..8be8f27bfaccdddf0dd1949d0dfd59ee63ad8ebc 100644 (file)
--- a/net/dccp/ipv4.c
+++ b/net/dccp/ipv4.c
@@ -204,8 +204,6 @@ void dccp_req_err(struct sock *sk, u64 seq)
         * ICMPs are not backlogged, hence we cannot get an established
         * socket here.
         */
-       WARN_ON(req->sk);
-
        if (!between48(seq, dccp_rsk(req)->dreq_iss, dccp_rsk(req)->dreq_gss)) {
                NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
        } else {

diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 8c7e63163e9258ae328f02271100055274339969..048418b049d845fb89a5c5aafb7192c29d6c4ce3 100644 (file)
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -320,8 +320,6 @@ 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) {