[PATCH net v3 0/2] vsock: validate packet sources after bound lookup fallback

[Daehyeon Ko <4ncienth@gmail.com>]

Both virtio and VMCI look up connected sockets by the full tuple before
falling back to a destination-only bound lookup. The fallback can select a
non-listening socket without validating the packet source.

V2 covered only the virtio path. Following Stefano's review, this series
moves the source and transport validation into a documented AF_VSOCK helper
and uses it for both virtio and VMCI. The VMCI patch checks both its
bottom-half and deferred workqueue receive paths.

The combined series was tested on x86_64 KASAN kernels. The original
cross-UID virtio injection remained blocked in three boots, CID_LOCAL and
CID_HOST loopback aliases passed, selected VSOCK selftests passed, and VMCI
accepted a matched RST while rejecting a mismatched-context RST in three
boots. All changed objects built without warnings under allmodconfig and
allyesconfig with W=1.

The current-tree guest-CID vhost probe could not be rerun because the test
user lacks access to /dev/vhost-vsock.

Changes in v3:
- Move transport and source validation into vsock_check_source().
- Trust the internally generated source CID for the local transport.
- Add VMCI validation in the bottom-half and workqueue receive paths.
- Send the related virtio and VMCI fixes in one series.
- Do not carry Bobby's v2 Reviewed-by because the helper and loopback logic
  changed; renewed review is requested.

v2: https://lore.kernel.org/netdev/20260820001517.2148196-1-4ncienth@gmail.com/
v1: https://lore.kernel.org/netdev/20260813121236.2328599-1-4ncienth@gmail.com/

Daehyeon Ko (2):
  vsock/virtio: validate packet source for connected sockets
  vsock/vmci: validate packet source for connected sockets

 include/net/af_vsock.h                  |  3 +++
 net/vmw_vsock/af_vsock.c                | 32 +++++++++++++++++++++++++
 net/vmw_vsock/virtio_transport_common.c |  3 ++-
 net/vmw_vsock/vmci_transport.c          | 29 +++++++++++++++++-----
 4 files changed, 60 insertions(+), 7 deletions(-)


base-commit: 7cbfb180945ce529608e4d4e24a6d483699fab1e
-- 
2.54.0