VULNERABILITY INTELLIGENCE
CVE-2026-53153
Description
In the Linux kernel, the following vulnerability has been resolved: mm/list_lru: drain before clearing xarray entry on reparent memcg_reparent_list_lrus() clears the dying memcg's xarray entry with xas_store(&xas, NULL) before reparenting its per-node lists into the parent. This opens a window where a concurrent list_lru_del() arriving for the dying memcg sees xa_load() == NULL, walks to the parent in lock_list_lru_of_memcg(), takes the parent's per-node lock, and calls list_del_init() on an item still physically linked on the dying memcg's list. If another in-flight thread holds the dying memcg's per-node lock at the same moment (another list_lru_del, or a list_lru_walk_one running an isolate callback), both threads modify ->next/->prev pointers on the same physical list under different locks. Adjacent items can corrupt each other's links. Fix it by reversing the order: reparent each per-node list and mark the child's list lru dead and then clear the xarray entry. Any concurrent list_lru op that finds the still-set xarray entry either takes the dying memcg's per-node lock (synchronizing with the drain) or sees LONG_MIN and walks to the parent, where the items now live.
Weakness classification
- CWE-820: Missing Synchronization
Primary references
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67 — Patch
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67 — Patch
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67 — Patch
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c — Third Party Advisory
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c — Third Party Advisory
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c — Third Party Advisory