CVE-2026-68294: net: qrtr: restrict socket creation to the initial network namespace

In the Linux kernel, the following vulnerability has been resolved:

net: qrtr: restrict socket creation to the initial network namespace

QRTR keeps its entire port and node state in module-global variables that are not partitioned per network namespace: qrtrlocalnid is a single global node id (always 1) and qrtrports is a single global xarray. qrtrportlookup() and qrtrlocalenqueue() operate on that global state with no network-namespace check, and qrtrcreate() places no restriction on the namespace a socket is created in.

As a result an unprivileged process that creates an AFQIPCRTR socket in a separate network namespace, e.g. via unshare(CLONENEWUSER | CLONENEWNET), can send QRTR datagrams - including control-plane messages such as QRTRTYPENEWSERVER - to QRTR sockets owned by another namespace, and vice versa. The receiving socket sees such a message as coming from node id 1, indistinguishable from a legitimate local client, breaking the isolation that network namespaces are expected to provide.

QRTR is a transport to global hardware endpoints (the modem and other remote processors) and has no per-namespace semantics; its in-kernel name service already creates its socket in initnet only. Confine the socket family to the initial network namespace, as other non-namespace-aware socket families do (see llcuicreate() and the ieee802154 socket code).