From 3c92fdb59f28fe16ddf2b812e7a0b7c1d903afc3 Mon Sep 17 00:00:00 2001 From: Stefano Garzarella Date: Tue, 23 Feb 2021 11:15:52 +0800 Subject: [PATCH] vsock: fix locking in vsock_shutdown() stable inclusion from stable-5.10.17 commit 69e9fd9de17e839920149e0906f4758667d3cee7 bugzilla: 48169 -------------------------------- 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 Signed-off-by: Zheng Zengkai Acked-by: Xie XiuQi --- net/vmw_vsock/af_vsock.c | 8 +++++--- net/vmw_vsock/hyperv_transport.c | 4 ---- 2 files changed, 5 insertions(+), 7 deletions(-) diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c index 66c9bc46891e..791955f5e7ec 100644 --- a/net/vmw_vsock/af_vsock.c +++ b/net/vmw_vsock/af_vsock.c @@ -926,10 +926,12 @@ 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; @@ -938,10 +940,8 @@ 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); @@ -949,6 +949,8 @@ 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 630b851f8150..cc3bae2659e7 100644 --- a/net/vmw_vsock/hyperv_transport.c +++ b/net/vmw_vsock/hyperv_transport.c @@ -474,14 +474,10 @@ 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; } -- GitLab