CVE-2026-90279 Affecting linux-6.12 package, versions <6.12.111-1~deb12u1


Severity

Recommended
low

Based on default assessment until relevant scores are available.

Threat Intelligence

EPSS
0.2% (11th percentile)

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  • Snyk IDSNYK-DEBIAN12-LINUX612-20506727
  • published5 Oct 2026
  • disclosed17 Sept 2026

Introduced: 17 Sep 2026

NewCVE-2026-90279  (opens in a new tab)

How to fix?

Upgrade Debian:12 linux-6.12 to version 6.12.111-1~deb12u1 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream linux-6.12 package and not the linux-6.12 package as distributed by Debian. See How to fix? for Debian:12 relevant fixed versions and status.

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

md/raid5: round bitmap stripes with sector division

raid5_bitmap_sector_map() aligns the array range to full RAID5 stripe widths before converting it to component sectors. That width is chunk_sectors multiplied by the number of data disks, and it is not always a power of two.

Reproduce with a 4-disk RAID5, 1024-sector chunks, and three data disks. The full-stripe width is 3072 sectors. For a one-sector write at array sector 3072, correct rounding gives array range [3072, 6144), which maps to component range [1024, 2048). The old round_down()/round_up() logic instead gives [1024, 4096), which maps to [0, 1024).

Use sector_div() based arithmetic so the rounded range is aligned to the actual RAID5 stripe width.

The deterministic mapper test now reports the fixed component range as [1024, 2048), while the old mask-based range was [0, 1024).