[CVE-2026-53162] In the Linux kernel, the following vulnerability has been resolved: memcg: use round-robin victim s…

Descripción técnica

In the Linux kernel, the following vulnerability has been resolved: memcg: use round-robin victim selection in refill_stock Harry Yoo reported that get_random_u32_below() is not safe to call in the nmi context and memcg charge draining can happen in nmi context. More specifically get_random_u32_below() is neither reentrant- nor NMI-safe: it acquires a per-cpu local_lock via local_lock_irqsave() on the batched_entropy_u32 state. An NMI that lands on a CPU mid-update of the ChaCha batch state and recurses into the random subsystem would corrupt that state. The memcg_stock local_trylock prevents re-entry on the percpu stock itself, but cannot protect an unrelated subsystem's per-cpu lock. Replace the random pick with a per-cpu round-robin counter stored in memcg_stock_pcp and serialized by the same local_trylock that already guards cached[] and nr_pages[]. No atomics, no random calls, no extra locks needed.

Puntuación CVSS

Score: 7.8/10 — Severidad: HIGH — Estado NIST: Analyzed

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Productos afectados

Linux kernel — Linux

Fuente oficial

Publicado en NIST NVD.