In the Linux kernel, the following vulnerability has been resolved:
ACPI: battery: Fix possible crash when unregistering a battery hook
When a battery hook returns an error when adding a new battery, then the battery hook is automatically unregistered. However the battery hook provider cannot know that, so it will later call batteryhookunregister() on the already unregistered battery hook, resulting in a crash.
Fix this by using the list head to mark already unregistered battery hooks as already being unregistered so that they can be ignored by batteryhookunregister().