vsock/vmci: validate packet source for connected sockets
Impact
In the Linux kernel, the following vulnerability has been resolved:
Source excerpt · LinuxAffected packages
Affected products
Vendor version evidence. Product records are separate from automatic dependency matching.
Linux · Linux
Other versions: unaffected
| Version / range | Source status |
|---|---|
| d021c344051af91f42c5ba9fdedc176740cbd238 to before c027f8b429dbb2157fc1b503df196e272d947c89 | affected |
| d021c344051af91f42c5ba9fdedc176740cbd238 to before 90c423b62ec9be08177f74b07a47937ca8d2035b | affected |
| d021c344051af91f42c5ba9fdedc176740cbd238 to before ad9a7da3fa39c2d616ec0dd3cf6e30531d032fe7 | affected |
Linux · Linux
Other versions: affected
| Version / range | Source status |
|---|---|
| 3.9 | affected |
| 0 to before 3.9 | unaffected |
| 6.18.59 through 6.18.* (inclusive) | unaffected |
| 7.2.13 through 7.2.* (inclusive) | unaffected |
| 7.3 through * (inclusive) | unaffected |
Original source description
In the Linux kernel, the following vulnerability has been resolved:
vsock/vmci: validate packet source for connected sockets
vmci_transport_recv_stream_cb() looks up sockets first by the full source and destination tuple, then by destination only in the bound table. The fallback can select a non-listening socket without checking whether the packet came from its stored peer.
This was reproduced with two VMCI contexts. A RST from the context not stored in a TCP_SYN_SENT socket reset that socket after it was selected by the destination-only lookup.
VMCI can process notification packets in bottom-half context when the socket is not owned by user context, or defer packets to a workqueue. Use vsock_check_source() after taking the socket lock in the bottom-half path, and recheck after lock_sock() in the workqueue path. Listening sockets continue to accept packets from any source.
Reply with a RST addressed from the received packet before dropping a source that fails validation. This preserves the existing reset behavior for bound non-listening and concurrently closed sockets without directing the reset to a connected socket's stored peer.