CVE-2026-64092: batman-adv: tp_meter: fix tp_vars reference leak in receiver shutdown

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-07-19 · updated 2026-08-11

Description

In the Linux kernel, the following vulnerability has been resolved: batman-adv: tp_meter: fix tp_vars reference leak in receiver shutdown The receiver shutdown timer handler, batadv_tp_receiver_shutdown(), is responsible for releasing the tp_vars reference it holds. However, the existing logic for coordinating this release with batadv_tp_stop_all() was flawed. timer_shutdown_sync() guarantees the timer will not fire again after it returns, but it returns non-zero only when the timer was pending at the time of the call. If the timer had already expired (and batadv_tp_stop_all() would unsucessfully try to rearm itself), batadv_tp_stop_all() skips its batadv_tp_vars_put(), and batadv_tp_receiver_shutdown() fails to put its own reference as well. Fix this by introducing a new atomic variable receiving that is set to 1 when the receiver is initialized and cleared atomically with atomic_xchg() by whichever side claims it first. Only the side that observes the transition from 1 to 0 is responsible for releasing the tp_vars timer reference, eliminating the uncertainty.

Affected products

Linux kernel: from 5.10.259 before 5.11; from 6.6.140 before 6.6.142; from 6.12.90 before 6.12.92; from 6.18.32 before 6.18.34; from 7.0.9 before 7.0.11; 7.1-rc4 — fixed in 5.11, 6.12.92, 6.18.34, 6.6.142, 7.0.11

How to fix

Upgrade to a fixed version: Linux kernel 5.11, 6.12.92, 6.18.34, 6.6.142. Check the vendor advisory for mitigations.

References

Get alerted when CVE-2026-64092 or the next vulnerability affects your stack