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

Official 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 packages & fixed versions

Affected products (as reported)

References

• https://git.kernel.org/stable/c/7715c73f33260af724d734c41b794457e9be8dbc
• https://git.kernel.org/stable/c/297e1bc4a915b7cd3e65a79ed906b23fb3d7aaae
• https://git.kernel.org/stable/c/0b1bedf114ea93fef929b31f0d70a9eedcc601de
• https://git.kernel.org/stable/c/a9f0bfd624ee8a286d6fd2bf0f796e730efb49b0
• https://git.kernel.org/stable/c/b285bc0a97f43823a4967fb6d286de4c7f53d541
• https://git.kernel.org/stable/c/d078501dde9b57210f1808cdef4b59463d1f5fc8
• https://git.kernel.org/stable/c/77098e4bea37af51d3962efa88a5af2ea5e1ac57