[PATCH 4.19 16/37] tipc: fix shutdown() of connection oriented socket

Greg Kroah-Hartman
2020-09-25T12:55:24Z

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
@@ -2565,10 +2565,7 @@ static int tipc_shutdown(struct socket *
lock_sock(sk);

__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 */