CVE-2026-89718

Status: UPDATED  |  Advisory ID: CVE-2026-89718

Key Details

Affected Products, Subsystems & Sectors

What to Know

In the Linux kernel, the following vulnerability has been resolved:

zram: fix out-of-bounds access in writeback_store()

Patch series "zram: fix stale scan bounds after reinitialization".

Both writeback_store() and read_block_state() derive their table scan

bounds from zram->disksize before acquiring dev_lock. If the device is

reset and reinitialized with a smaller disksize between that read and lock

acquisition, the bound can describe the old table while the scan operates

on the new one. This can lead to out-of-bounds slot accesses.

Move both bound calculations under dev_lock so each bound remains

consistent with the table throughout its scan. Keep the fixes separate

because the affected interfaces originate from different commits and can

be backported independently.

This patch (of 2):

writeback_store() calculates the table scan bounds before taking dev_lock.

A reset followed by reconfiguration with a smaller disksize can therefore

replace zram->table while writeback_store() is waiting for the lock. Once

it acquires the lock, it sees an initialized device but scans the new

table using the old upper bound, resulting in an out-of-bounds access.

Calculate the number of pages while holding dev_lock so the scan bound

matches the table protected by the lock. (NVD)

What to Do

Monitor Linux's web page for any future patch releases.

References