From 8236b08cf50f85bbfaf48910a0b3ee68318b7c4b Mon Sep 17 00:00:00 2001 From: Lepton Wu Date: Tue, 11 Dec 2018 11:12:55 -0800 Subject: [PATCH] VSOCK: bind to random port for VMADDR_PORT_ANY The old code always starts from fixed port for VMADDR_PORT_ANY. Sometimes when VMM crashed, there is still orphaned vsock which is waiting for close timer, then it could cause connection time out for new started VM if they are trying to connect to same port with same guest cid since the new packets could hit that orphaned vsock. We could also fix this by doing more in vhost_vsock_reset_orphans, but any way, it should be better to start from a random local port instead of a fixed one. Signed-off-by: Lepton Wu Reviewed-by: Jorgen Hansen Signed-off-by: David S. Miller --- net/vmw_vsock/af_vsock.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c index ab27a2872935..43a1dec08825 100644 --- a/net/vmw_vsock/af_vsock.c +++ b/net/vmw_vsock/af_vsock.c @@ -107,6 +107,7 @@ #include #include #include +#include #include #include #include @@ -504,9 +505,13 @@ static void vsock_pending_work(struct work_struct *work) static int __vsock_bind_stream(struct vsock_sock *vsk, struct sockaddr_vm *addr) { - static u32 port = LAST_RESERVED_PORT + 1; + static u32 port = 0; struct sockaddr_vm new_addr; + if (!port) + port = LAST_RESERVED_PORT + 1 + + prandom_u32_max(U32_MAX - LAST_RESERVED_PORT); + vsock_addr_init(&new_addr, addr->svm_cid, addr->svm_port); if (addr->svm_port == VMADDR_PORT_ANY) {