diff options
| author | Bobby Eshleman <bobbyeshleman@meta.com> | 2026-02-23 14:38:33 -0800 |
|---|---|---|
| committer | Paolo Abeni <pabeni@redhat.com> | 2026-02-26 11:10:03 +0100 |
| commit | 102eab95f025b4d3f3a6c0a858400aca2af2fe52 (patch) | |
| tree | 4d0fab584ded0214cbfc94a730c755dadffdfc3b /include/net/netns | |
| parent | a382a34276cb94d1cdc620b622dd85c55589a166 (diff) | |
vsock: lock down child_ns_mode as write-once
Two administrator processes may race when setting child_ns_mode as one
process sets child_ns_mode to "local" and then creates a namespace, but
another process changes child_ns_mode to "global" between the write and
the namespace creation. The first process ends up with a namespace in
"global" mode instead of "local". While this can be detected after the
fact by reading ns_mode and retrying, it is fragile and error-prone.
Make child_ns_mode write-once so that a namespace manager can set it
once and be sure it won't change. Writing a different value after the
first write returns -EBUSY. This applies to all namespaces, including
init_net, where an init process can write "local" to lock all future
namespaces into local mode.
Fixes: eafb64f40ca4 ("vsock: add netns to vsock core")
Suggested-by: Daan De Meyer <daan.j.demeyer@gmail.com>
Suggested-by: Stefano Garzarella <sgarzare@redhat.com>
Co-developed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Bobby Eshleman <bobbyeshleman@meta.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Link: https://patch.msgid.link/20260223-vsock-ns-write-once-v3-2-c0cde6959923@meta.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Diffstat (limited to 'include/net/netns')
| -rw-r--r-- | include/net/netns/vsock.h | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/include/net/netns/vsock.h b/include/net/netns/vsock.h index b34d69a22fa8..dc8cbe45f406 100644 --- a/include/net/netns/vsock.h +++ b/include/net/netns/vsock.h @@ -17,5 +17,8 @@ struct netns_vsock { enum vsock_net_mode mode; enum vsock_net_mode child_ns_mode; + + /* 0 = unlocked, 1 = locked to global, 2 = locked to local */ + int child_ns_mode_locked; }; #endif /* __NET_NET_NAMESPACE_VSOCK_H */ |