[PATCH 4.17 26/66] tls: check RCV_SHUTDOWN in tls_wait_data

[Greg Kroah-Hartman]

4.17-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Doron Roberts-Kedes <doronrk@xxxxxx>

[ Upstream commit fcf4793e278edede8fcd748198d12128037e526c ]

The current code does not check sk->sk_shutdown & RCV_SHUTDOWN.
tls_sw_recvmsg may return a positive value in the case where bytes have
already been copied when the socket is shutdown. sk->sk_err has been
cleared, causing the tls_wait_data to hang forever on a subsequent
invocation. Checking sk->sk_shutdown & RCV_SHUTDOWN, as in tcp_recvmsg,
fixes this problem.

Fixes: c46234ebb4d1 ("tls: RX path for ktls")
Acked-by: Dave Watson <davejwatson@xxxxxx>
Signed-off-by: Doron Roberts-Kedes <doronrk@xxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 net/tls/tls_sw.c |    3 +++
 1 file changed, 3 insertions(+)

--- a/net/tls/tls_sw.c
+++ b/net/tls/tls_sw.c
@@ -646,6 +646,9 @@ static struct sk_buff *tls_wait_data(str
 			return NULL;
 		}
 
+		if (sk->sk_shutdown & RCV_SHUTDOWN)
+			return NULL;
+
 		if (sock_flag(sk, SOCK_DONE))
 			return NULL;