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authorStefano Garzarella <sgarzare@redhat.com>2021-02-09 11:52:19 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2021-02-23 17:00:58 +0300
commitb3c91763e2e40cad3cf7753e0a1c8045ec31985b (patch)
tree47e36eb566a5c849faf4369dfdb1951332af6f2c
parentafb1f8a1ea17cd156ee8e17ad76fb5fc3e1d332b (diff)
downloadlinux-b3c91763e2e40cad3cf7753e0a1c8045ec31985b.tar.xz
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 <sgarzare@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--net/vmw_vsock/af_vsock.c8
-rw-r--r--net/vmw_vsock/hyperv_transport.c4
2 files changed, 5 insertions, 7 deletions
diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
index d02ccda10ba5..4b65db13e1bb 100644
--- a/net/vmw_vsock/af_vsock.c
+++ b/net/vmw_vsock/af_vsock.c
@@ -816,10 +816,12 @@ 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;
@@ -828,10 +830,8 @@ 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);
@@ -839,6 +839,8 @@ static int vsock_shutdown(struct socket *sock, int mode)
}
}
+out:
+ release_sock(sk);
return err;
}
diff --git a/net/vmw_vsock/hyperv_transport.c b/net/vmw_vsock/hyperv_transport.c
index db6ca51228d2..2bdf36845a5f 100644
--- a/net/vmw_vsock/hyperv_transport.c
+++ b/net/vmw_vsock/hyperv_transport.c
@@ -443,14 +443,10 @@ static void hvs_shutdown_lock_held(struct hvsock *hvs, int mode)
static int hvs_shutdown(struct vsock_sock *vsk, int mode)
{
- struct sock *sk = sk_vsock(vsk);
-
if (!(mode & SEND_SHUTDOWN))
return 0;
- lock_sock(sk);
hvs_shutdown_lock_held(vsk->trans, mode);
- release_sock(sk);
return 0;
}