From: Budimir Markovic Date: Thu, 7 Aug 2025 04:18:11 +0000 (+0000) Subject: vsock: Do not allow binding to VMADDR_PORT_ANY X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=aba0c94f61ec05315fa7815d21aefa4c87f6a9f4;p=users%2Fjedix%2Flinux-maple.git vsock: Do not allow binding to VMADDR_PORT_ANY It is possible for a vsock to autobind to VMADDR_PORT_ANY. This can cause a use-after-free when a connection is made to the bound socket. The socket returned by accept() also has port VMADDR_PORT_ANY but is not on the list of unbound sockets. Binding it will result in an extra refcount decrement similar to the one fixed in fcdd2242c023 (vsock: Keep the binding until socket destruction). Modify the check in __vsock_bind_connectible() to also prevent binding to VMADDR_PORT_ANY. Fixes: d021c344051a ("VSOCK: Introduce VM Sockets") Reported-by: Budimir Markovic Signed-off-by: Budimir Markovic Reviewed-by: Stefano Garzarella Link: https://patch.msgid.link/20250807041811.678-1-markovicbudimir@gmail.com Signed-off-by: Jakub Kicinski --- diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c index ead6a3c14b87..bebb355f3ffe 100644 --- a/net/vmw_vsock/af_vsock.c +++ b/net/vmw_vsock/af_vsock.c @@ -689,7 +689,8 @@ static int __vsock_bind_connectible(struct vsock_sock *vsk, unsigned int i; for (i = 0; i < MAX_PORT_RETRIES; i++) { - if (port <= LAST_RESERVED_PORT) + if (port == VMADDR_PORT_ANY || + port <= LAST_RESERVED_PORT) port = LAST_RESERVED_PORT + 1; new_addr.svm_port = port++;