CVE-2026-53162
HighCVSS 7.8Exploitation Probability (EPSS)
Low risk3th percentile — higher than 3% of all known CVEs
Summary
In the Linux kernel, a vulnerability in memcg's refill_stock uses get_random_u32_below() which is unsafe in NMI context, potentially corrupting the ChaCha batch state. The fix replaces random selection with a per-CPU round-robin counter.
Risk Assessment
The risk involves potential corruption of the random subsystem state during NMI interrupts, leading to unpredictable kernel behavior, crashes, or data integrity issues.
Recommendation
Immediately update the Linux kernel to a version containing the fix (commit addressing the issue). Monitor distributions for the patch release.
Original NVD description (English source)
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.