CVE-2026-64218

About vulnerability

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.

Affected product:

AlmaLinux 9.2 ESU , Amazon Linux 2 ELS , CentOS 7 ELS , CentOS 8.4 ELS , CentOS 8.5 ELS , CentOS Stream 8 ELS , CloudLinux 7 ELS , Debian 10 ELS , Oracle Linux 7 ELS , RHEL 7 ELS , TuxCare 9.6 ESU , Ubuntu 16.04 ELS , Ubuntu 18.04 ELS , Ubuntu 20.04 ELS

Affected packages:

linux @ 4.19.0 (+15 more)

Live-patch status from KernelCare for each operating system.