From d8a3f2ac33bdcde58c70befb0c9396a77c87d948 Mon Sep 17 00:00:00 2001 From: Stefano Garzarella Date: Tue, 9 Feb 2021 09:52:19 +0100 Subject: [PATCH] vsock: fix locking in vsock_shutdown() commit 1c5fae9c9a092574398a17facc31c533791ef232 upstream. In vsock_shutdown() we touched some socket fields without holding the socket lock, such as 'state' and 'sk_flags'. Also, after the introduction of multi-transport, we are accessing 'vsk->transport' in vsock_send_shutdown() without holding the lock and this call can be made while the connection is in progress, so the transport can change in the meantime. To avoid issues, we hold the socket lock when we enter in vsock_shutdown() and release it when we leave. Among the transports that implement the 'shutdown' callback, only hyperv_transport acquired the lock. Since the caller now holds it, we no longer take it. Fixes: d021c344051a ("VSOCK: Introduce VM Sockets") Signed-off-by: Stefano Garzarella Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/vmw_vsock/af_vsock.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c index 70e2c4def7a6..bd3a5ef8e59b 100644 --- a/net/vmw_vsock/af_vsock.c +++ b/net/vmw_vsock/af_vsock.c @@ -830,10 +830,12 @@ static int vsock_shutdown(struct socket *sock, int mode) */ sk = sock->sk; + + lock_sock(sk); if (sock->state == SS_UNCONNECTED) { err = -ENOTCONN; if (sk->sk_type == SOCK_STREAM) - return err; + goto out; } else { sock->state = SS_DISCONNECTING; err = 0; @@ -842,10 +844,8 @@ static int vsock_shutdown(struct socket *sock, int mode) /* Receive and send shutdowns are treated alike. */ mode = mode & (RCV_SHUTDOWN | SEND_SHUTDOWN); if (mode) { - lock_sock(sk); sk->sk_shutdown |= mode; sk->sk_state_change(sk); - release_sock(sk); if (sk->sk_type == SOCK_STREAM) { sock_reset_flag(sk, SOCK_DONE); @@ -853,6 +853,8 @@ static int vsock_shutdown(struct socket *sock, int mode) } } +out: + release_sock(sk); return err; }