---
id: CVE-2026-90043
title: |-
  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
summary: |-
  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-…
severity: high
cvss: 7.8
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 2e8ff2f51dde73a26b94aed2df4827177bd25e6e <
    052b6b2d5fe97547bd2cdb73fa894f6cfea68b11
  - >-
    Linux >= 2e8ff2f51dde73a26b94aed2df4827177bd25e6e <
    a8b5875741d416703e19ad8eeac6fce8a12bd6e4
  - Linux 7.0
published: '2026-09-16'
updated: '2026-09-16'
sourceUpdated: '2026-09-16T15:18:26.990'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-90043'
references:
  - url: 'https://git.kernel.org/stable/c/052b6b2d5fe97547bd2cdb73fa894f6cfea68b11'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/a8b5875741d416703e19ad8eeac6fce8a12bd6e4'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
tags:
  - nvd
  - cve.org
ingestedAt: '2026-09-16T10:53:53.929Z'
epss: 0.00165
epssPercentile: 0.05052
---

## Overview

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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.