On Mon, Jan 12, 2026 at 04:52:31PM -0800, Bobby Eshleman wrote:
On Mon, Jan 12, 2026 at 03:34:31PM -0800, Bobby Eshleman wrote:
On Sun, Jan 11, 2026 at 01:43:37AM -0500, Michael S. Tsirkin wrote:
On Tue, Dec 23, 2025 at 04:28:36PM -0800, Bobby Eshleman wrote:
From: Bobby Eshleman bobbyeshleman@meta.com
Add netns logic to vsock core. Additionally, modify transport hook prototypes to be used by later transport-specific patches (e.g., *_seqpacket_allow()).
Namespaces are supported primarily by changing socket lookup functions (e.g., vsock_find_connected_socket()) to take into account the socket namespace and the namespace mode before considering a candidate socket a "match".
This patch also introduces the sysctl /proc/sys/net/vsock/ns_mode to report the mode and /proc/sys/net/vsock/child_ns_mode to set the mode for new namespaces.
Add netns functionality (initialization, passing to transports, procfs, etc...) to the af_vsock socket layer. Later patches that add netns support to transports depend on this patch.
dgram_allow(), stream_allow(), and seqpacket_allow() callbacks are modified to take a vsk in order to perform logic on namespace modes. In future patches, the net will also be used for socket lookups in these functions.
Signed-off-by: Bobby Eshleman bobbyeshleman@meta.com
...
static int __vsock_bind_connectible(struct vsock_sock *vsk, struct sockaddr_vm *addr) {
- struct net *net = sock_net(sk_vsock(vsk)); static u32 port; struct sockaddr_vm new_addr;
Hmm this static port gives me pause. So some port number info leaks between namespaces. I am not saying it's a big security issue and yet ... people expect isolation.
Probably the easiest solution is making it per-ns, my quick rough draft looks like this:
diff --git a/include/net/netns/vsock.h b/include/net/netns/vsock.h index e2325e2d6ec5..b34d69a22fa8 100644 --- a/include/net/netns/vsock.h +++ b/include/net/netns/vsock.h @@ -11,6 +11,10 @@ enum vsock_net_mode { struct netns_vsock { struct ctl_table_header *sysctl_hdr;
- /* protected by the vsock_table_lock in af_vsock.c */
- u32 port;
- enum vsock_net_mode mode; enum vsock_net_mode child_ns_mode;
}; diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c index 9d614e4a4fa5..cd2a47140134 100644 --- a/net/vmw_vsock/af_vsock.c +++ b/net/vmw_vsock/af_vsock.c @@ -748,11 +748,10 @@ static int __vsock_bind_connectible(struct vsock_sock *vsk, struct sockaddr_vm *addr) { struct net *net = sock_net(sk_vsock(vsk));
- static u32 port; struct sockaddr_vm new_addr;
- if (!port)
port = get_random_u32_above(LAST_RESERVED_PORT);
- if (!net->vsock.port)
net->vsock.port = get_random_u32_above(LAST_RESERVED_PORT);vsock_addr_init(&new_addr, addr->svm_cid, addr->svm_port); @@ -761,11 +760,11 @@ static int __vsock_bind_connectible(struct vsock_sock *vsk, unsigned int i; for (i = 0; i < MAX_PORT_RETRIES; i++) {
if (port == VMADDR_PORT_ANY ||port <= LAST_RESERVED_PORT)port = LAST_RESERVED_PORT + 1;
if (net->vsock.port == VMADDR_PORT_ANY ||net->vsock.port <= LAST_RESERVED_PORT)net->vsock.port = LAST_RESERVED_PORT + 1;
new_addr.svm_port = port++;
new_addr.svm_port = net->vsock.port++;if (!__vsock_find_bound_socket_net(&new_addr, net)) { found = true;
Another option being to follow inet's path and use siphash_4u32() the way that secure_ipv4_port_ephemeral() does...
Also acceptable.