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

Summary

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.

Timeline

1. Jul 19, 2026, 3:40 PM UTCCVE published

Affected versions

• Linux Linux

  From 5.10.259 · fixed in 5.11

• Linux Linux

  From 6.6.140 · fixed in 6.6.142; From 6.12.90 · fixed in 6.12.92; From 6.18.32 · fixed in 6.18.34; From 7.0.9 · fixed in 7.0.11

References 7