CVE-2026-53153

Summary

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.

Affected Software

VendorProductVersion RangeStatus
LinuxLinuxfb56fdf8b9a2f7397f8a83dce50189f3f0cf71af < c19ff4351214f059349788e13e70e74325831ff6affected
LinuxLinuxfb56fdf8b9a2f7397f8a83dce50189f3f0cf71af < 2b66496d794e98f7aeec7688573051f22ec40bacaffected
LinuxLinuxfb56fdf8b9a2f7397f8a83dce50189f3f0cf71af < 98733f3f0becb1ae0701d021c1748e974e5fa55caffected
LinuxLinux6.13affected
LinuxLinux0 < 6.13unaffected
LinuxLinux6.18.36 <= 6.18.*unaffected
LinuxLinux7.0.13 <= 7.0.*unaffected
LinuxLinux7.1 <= *unaffected

Weaknesses

ADP Enrichment

kernel: mm/list_lru: drain before clearing xarray entry on reparent

Additional References

References