From 3b536db8fb32da9e9c62f2bb45e2e319331f0426 Mon Sep 17 00:00:00 2001 From: Aldo Ariel Panzardo Date: Thu, 16 Jul 2026 12:43:19 -0300 Subject: [PATCH] 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: qrtr_local_nid is a single global node id (always 1) and qrtr_ports is a single global xarray. qrtr_port_lookup() and qrtr_local_enqueue() operate on that global state with no network-namespace check, and qrtr_create() places no restriction on the namespace a socket is created in. As a result an unprivileged process that creates an AF_QIPCRTR socket in a separate network namespace, e.g. via unshare(CLONE_NEWUSER | CLONE_NEWNET), can send QRTR datagrams - including control-plane messages such as QRTR_TYPE_NEW_SERVER - 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 init_net only. Confine the socket family to the initial network namespace, as other non-namespace-aware socket families do (see llc_ui_create() and the ieee802154 socket code). Fixes: bdabad3e363d ("net: Add Qualcomm IPC router") Signed-off-by: Aldo Ariel Panzardo Link: https://patch.msgid.link/20260716154319.3297699-1-qwe.aldo@gmail.com Signed-off-by: Jakub Kicinski --- net/qrtr/af_qrtr.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/net/qrtr/af_qrtr.c b/net/qrtr/af_qrtr.c index d02ef9a74c3ca..a30fa56e6aa31 100644 --- a/net/qrtr/af_qrtr.c +++ b/net/qrtr/af_qrtr.c @@ -1263,6 +1263,14 @@ static int qrtr_create(struct net *net, struct socket *sock, if (sock->type != SOCK_DGRAM) return -EPROTOTYPE; + /* QRTR keeps its port and node state in module-global variables that + * are not partitioned per network namespace, and the in-kernel name + * service only operates in init_net. Confine the family to init_net so + * a socket in another namespace cannot reach the global control plane. + */ + if (!net_eq(net, &init_net)) + return -EAFNOSUPPORT; + sk = sk_alloc(net, AF_QIPCRTR, GFP_KERNEL, &qrtr_proto, kern); if (!sk) return -ENOMEM; -- 2.47.3