Commit e316ea62 authored Mar 16, 2016 by Eric Dumazet Committed by David S. Miller Mar 17, 2016

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: 079096f1 ("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>

parent f6773c5e

net/dccp/ipv4.c

+0 −2

Original line number	Diff line number	Diff line
		@@ -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 {

net/ipv4/tcp_ipv4.c

+0 −2

Original line number	Diff line number	Diff line
		@@ -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) {

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