Shakeel Butt

**Name of the Vulnerable Software and Affected Versions** Linux kernel (affected versions not specified) **Description** The issue is related to the protection of concurrent access to `mem cgroup idr` in the Linux kernel. The problem arises when `idr remove()` is called concurrently for different `memcgs` when they reach a reference count of zero. This can cause multiple `memcgs` to acquire the same ID, leading to crashes due to missing `list lru one` when other `memcgs` access the `list lru`. The kernel crashes were observed at a low frequency in the fleet, particularly in the `list lru` code, including `list lru add()`, `list lru del()`, and reparenting code. **Recommendations** At the moment, there is no information about a newer version that contains a fix for this vulnerability.