CVE-2026-72127

Technical Description

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

netdev-genl: report NAPI thread PID in the caller's pid namespace

netdev_nl_napi_fill_one() reports the NAPI kthread PID in NETDEV_A_NAPI_PID

using task_pid_nr(), which returns the PID in the initial pid namespace.

NETDEV_CMD_NAPI_GET does not have GENL_ADMIN_PERM and the netdev genl family

is netnsok, so a caller in a child pid namespace can issue it. That caller

then sees the kthread's global PID, even though the kthread is not visible

in its pid namespace, where the value should be 0.

Translate the PID through the caller's pid namespace, the same way commit

3799c2570982 ("io_uring/fdinfo: translate SqThread PID through caller's

pid_ns") did for the io_uring SQPOLL thread. The doit and dumpit paths both

run synchronously in the caller's context, so task_active_pid_ns(current) is

the caller's pid namespace.

Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

References