Linux Kernel CVE-2026-64092

The batman-adv (Better Approach To Mobile Adhoc Networking Advanced) module is a Layer 2 mesh networking protocol implementation in the Linux kernel, designed for wireless ad-hoc and mesh network scenarios. Its tp_meter component provides throughput measurement between mesh nodes. The vulnerability lies in the reference counting lifecycle of tp_vars structures: timer_shutdown_sync() returns non-zero only when the timer was actively pending at call time. If the receiver shutdown timer had already fired by the time batadv_tp_stop_all() invokes timer_shutdown_sync(), neither batadv_tp_stop_all() (which skips its batadv_tp_vars_put()) nor batadv_tp_receiver_shutdown() (which detects no pending transition) releases the reference. This constitutes a resource management failure consistent with CWE-772 (Missing Release of Resource after Effective Lifetime). The upstream fix introduces a new atomic variable receiving, initialized to 1 on receiver setup and atomically cleared via atomic_xchg(), so exactly one side observes the 1→0 transition and bears sole responsibility for releasing the timer reference. Affected CPE: cpe:2.3:a:linux:linux:*:*:*:*:*:*:*:*.