From 39354eb29f597aa01b3d51ccc8169cf183c4367f Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Sat, 13 Feb 2021 06:26:34 -0800 Subject: [PATCH] tcp: tcp_data_ready() must look at SOCK_DONE My prior cleanup missed that tcp_data_ready() has to look at SOCK_DONE. Otherwise, an application using SO_RCVLOWAT will not get EPOLLIN event if a FIN is received in the middle of expected payload. The reason SOCK_DONE is not examined in tcp_epollin_ready() is that tcp_poll() catches the FIN because tcp_fin() is also setting RCV_SHUTDOWN into sk->sk_shutdown Fixes: 05dc72aba364 ("tcp: factorize logic into tcp_epollin_ready()") Signed-off-by: Eric Dumazet Reported-by: Wei Wang Cc: Arjun Roy Reviewed-by: Wei Wang Signed-off-by: David S. Miller --- net/ipv4/tcp_input.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index e32a7056cb76..69a545db80d2 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -4924,7 +4924,7 @@ err: void tcp_data_ready(struct sock *sk) { - if (tcp_epollin_ready(sk, sk->sk_rcvlowat)) + if (tcp_epollin_ready(sk, sk->sk_rcvlowat) || sock_flag(sk, SOCK_DONE)) sk->sk_data_ready(sk); } -- 2.34.1