CVE-2026-90043

zram: fix slot lock bit position on big-endian 64-bit

HIGH
7.8
CVSS Score
Published: September 16, 2026 at 10:33 AM UTC
Updated: October 19, 2026 at 09:18 AM UTC
1 product affected across 1 vendorLinux Kernel

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Severity
HIGH7.8
Exploit prediction
EPSS 0.2%

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

2e8ff2f51dde73a26b94aed2df4827177bd25e6e7.0
Vendor states this is fixed in 052b6b2d5fe97547bd2cdb73fa894f6cfea68b11 (fixed)
Vendor states this is fixed in a8b5875741d416703e19ad8eeac6fce8a12bd6e4 (fixed)
Vendor states this is fixed in 7.0 (unaffected)
Vendor states this is fixed in 7.2.5 (unaffected)
Vendor states this is fixed in 7.3 (unaffected)
Vendor states this is fixed in 7.3-rc1 (unaffected)

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

CVSS

7.8HIGHLinux
Vector?

Quick Info

StatusRECEIVED

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