5.10-stable review patch. If anyone has any objections, please let me know.
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From: Eric Dumazet edumazet@google.com
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 --- net/ipv4/tcp_input.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -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); }