tcp: tcp_data_ready() must look at SOCK_DONE

commit 39354eb29f597aa01b3d51ccc8169cf183c4367f upstream.

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 <edumazet@google.com>
Reported-by: Wei Wang <weiwan@google.com>
Cc: Arjun Roy <arjunroy@google.com>
Reviewed-by: Wei Wang <weiwan@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Eric Dumazet
2021-02-13 06:26:34 -08:00
committed by Greg Kroah-Hartman
parent 775d9a08c4
commit 9cb3144045

View File

@@ -5028,7 +5028,7 @@ 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);
}