Medium [CVE-2026-53162] use round-robin victim selection in refill_stock
This medium-severity Red Hat Linux advisory covers CVE-2026-53162 affecting Red Hat Enterprise Linux 6, Red Hat package: kernel.
Aggregated and source-linked by VulniPulse. Data sources, validation and limitations.
VulniPulse record published Record updated
Summary
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. A flaw was found in the Linux kernel's memory cgroup (memcg) subsystem.
When a non-maskable interrupt (NMI) occurs during an update of the system's random number generation state, it can lead to corruption of that state. This issue can result in memory cgroup charge draining, potentially causing system instability or a denial of service.
Red Hat severity: Moderate — CVSS 5.5 (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H). Weakness: CWE-366.
Is CVE-2026-53162 exploited?
No exploitation is reported in the sources VulniPulse tracks: CVE-2026-53162 is not in the CISA KEV catalog (checked ) and this advisory does not report exploitation. That is not proof the vulnerability cannot be exploited.
How do I fix CVE-2026-53162?
The advisory VulniPulse tracks names no fixed release. Follow Red Hat's guidance for workarounds and updates.
Confirm against the vendor advisory before you patch.
Affected versions
No affected-version range was extracted from the source record. The vendor advisory is authoritative. Check it before change work.
Official advisory · medium-confidence parse· fetched 15 days ago·verify at source
Fixed versions
No fixed release is recorded yet. That does not prove no patch exists. Confirm against the vendor advisory.
Official advisory · medium-confidence parse· fetched 15 days ago·verify at source
Mitigation
The source record does not include mitigation steps. That does not mean no fix exists. Read the vendor advisory below for the authoritative guidance.
Official advisory · medium-confidence parse· fetched 15 days ago·verify at source
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