[PATCH 5.4 28/43] tipc: fix shutdown() of connection oriented socket - Greg Kroah-Hartman

From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	stable@vger.kernel.org,
	Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>,
	Ying Xue <ying.xue@windriver.com>,
	"David S. Miller" <davem@davemloft.net>
Subject: [PATCH 5.4 28/43] tipc: fix shutdown() of connection oriented socket
Date: Fri, 25 Sep 2020 14:48:40 +0200	[thread overview]
Message-ID: <20200925124727.855518076@linuxfoundation.org> (raw)
In-Reply-To: <20200925124723.575329814@linuxfoundation.org>

From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>

[ Upstream commit a4b5cc9e10803ecba64a7d54c0f47e4564b4a980 ]

I confirmed that the problem fixed by commit 2a63866c8b51a3f7 ("tipc: fix
shutdown() of connectionless socket") also applies to stream socket.

----------
#include <sys/socket.h>
#include <unistd.h>
#include <sys/wait.h>

int main(int argc, char *argv[])
{
        int fds[2] = { -1, -1 };
        socketpair(PF_TIPC, SOCK_STREAM /* or SOCK_DGRAM */, 0, fds);
        if (fork() == 0)
                _exit(read(fds[0], NULL, 1));
        shutdown(fds[0], SHUT_RDWR); /* This must make read() return. */
        wait(NULL); /* To be woken up by _exit(). */
        return 0;
}
----------

Since shutdown(SHUT_RDWR) should affect all processes sharing that socket,
unconditionally setting sk->sk_shutdown to SHUTDOWN_MASK will be the right
behavior.

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 net/tipc/socket.c |    5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

--- a/net/tipc/socket.c
+++ b/net/tipc/socket.c
@@ -2616,10 +2616,7 @@ static int tipc_shutdown(struct socket *
 
 	trace_tipc_sk_shutdown(sk, NULL, TIPC_DUMP_ALL, " ");
 	__tipc_shutdown(sock, TIPC_CONN_SHUTDOWN);
-	if (tipc_sk_type_connectionless(sk))
-		sk->sk_shutdown = SHUTDOWN_MASK;
-	else
-		sk->sk_shutdown = SEND_SHUTDOWN;
+	sk->sk_shutdown = SHUTDOWN_MASK;
 
 	if (sk->sk_state == TIPC_DISCONNECTING) {
 		/* Discard any unreceived messages */


