| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.5 050/124] tcp/dccp: remove obsolete WARN_ON() in icmp handlers | Date | Mon, 18 Apr 2016 11:28:42 +0900 |
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4.5-stable review patch. If anyone has any objections, please let me know.
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From: Eric Dumazet <edumazet@google.com>
[ 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> --- net/dccp/ipv4.c | 2 -- net/ipv4/tcp_ipv4.c | 2 -- 2 files changed, 4 deletions(-)
--- a/net/dccp/ipv4.c +++ b/net/dccp/ipv4.c @@ -204,8 +204,6 @@ void dccp_req_err(struct sock *sk, u64 s * 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 { --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -319,8 +319,6 @@ void tcp_req_err(struct sock *sk, u32 se /* 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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