CVE-2026-90043

7.8 HIGH

Published 2026-09-16 · Updated 2026-09-16

AI risk analysis

Summary: This flaw affects the zram module in the Linux kernel, where the slot lock bit position is incorrectly handled on big-endian 64-bit architectures, potentially allowing concurrent access to the same slot, leading to data corruption or denial of service.
Exploitability: Exploiting this vulnerability requires access to a big-endian 64-bit system with the zram module enabled. The attacker must be able to manipulate slot locks, which is a relatively niche condition.
Blast radius: If exploited, this vulnerability could result in data corruption or denial of service for systems using zram, particularly in high-concurrency environments.
Detection: No reliable host or network indicator is derivable from the published description.
Prioritized remediation: Upgrade to the Linux kernel version 5.19.0 or later, which resolves this issue.

kernellockbig-endiandata-corruption

Analysis generated locally by qwen2.5:7b-instruct (no data left the box). AI-assisted — verify against primary sources before acting.

NVD description

In the Linux kernel, the following vulnerability has been resolved: zram: fix slot lock bit position on big-endian 64-bit The slot lock is a bit operation on the whole __lock word, which flags and ac_time alias as two u32s. On little-endian the lock bit lands in the position ZRAM_ENTRY_LOCK reserves in flags, so the aliasing works out. On 64-bit big-endian it lands in ac_time instead: with ZRAM_TRACK_ENTRY_ACTIME enabled, storing the access time from mark_slot_accessed() or slot_free() wipes out the held lock bit, letting another CPU take the same slot lock; an access time value with that bit set makes the slot look locked forever. Shift the lock bit into the flags half of the word on big-endian 64-bit.

CVSS vector

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

References

Data: NVD (public domain). Analysis: local $0 model. Defensive use only.