CVE-2026-64218
Description
In the Linux kernel, the following vulnerability has been resolved:
batman-adv: bla: fix report_work leak on backbone_gw purge
batadv_bla_purge_backbone_gw() removes stale backbone gateway entries,
but fails to properly handle their associated report_work:
- If report_work is running, the purge must wait for it to finish before
freeing the backbone_gw, otherwise the worker may access freed memory
(e.g. bat_priv).
- If report_work is pending, the purge must cancel it and release the
reference held for that pending work item.
The previous implementation called hlist_for_each_entry_safe() inside a
spin_lock_bh() section, but cancel_work_sync() may sleep and therefore
cannot be called from within a spinlock-protected region.
Restructure the loop to handle one entry per spinlock critical section:
acquire the lock, find the next entry to purge, remove it from the hash
list, then release the lock before calling cancel_work_sync() and
dropping the hash_entry reference. Repeat until no more entries require
purging.