---
id: CVE-2026-53130
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  fs/omfs: reject s_sys_blocksize smaller than OMFS_DIR_START

  omfs_fill_super() rejects oversized s_sys_blocksize values (> PAGE_SIZE),
  but it does not reject values sma…
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  fs/omfs: reject s_sys_blocksize smaller than OMFS_DIR_START

  omfs_fill_super() rejects oversized s_sys_blocksize values (> PAGE_SIZE),
  but it does not reject values sma…
severity: high
cvss: 7.8
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H'
cwe:
  - CWE-191
vendor: linux
product: linux_kernel
affected:
  - 'linux_kernel >= 2.6.27, < 5.10.258'
  - 'linux_kernel >= 5.11, < 5.15.209'
  - 'linux_kernel >= 5.16, < 6.1.175'
  - 'linux_kernel >= 6.2, < 6.6.141'
  - 'linux_kernel >= 6.7, < 6.12.91'
  - 'linux_kernel >= 6.13, < 6.18.33'
  - 'linux_kernel >= 6.19, < 7.0.10'
patched:
  - linux_kernel 7.0.10
published: '2026-06-24'
updated: '2026-07-06'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-53130'
references:
  - url: 'https://git.kernel.org/stable/c/0621c385fda1376e967f37ccd534c26c3e511d14'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/131ea3e57fc22936ed0e2c8330f2e36106172f51'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/5822a05a841a10794ad818620dd2af490b0705d3'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/6561afc38398e3518a29c5eebb975c30468f98a6'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/754ff1bea3819a90c6f33cccfc1a299ef7609f07'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/79f84af38c9fef9deb0e02c79eb969b5541c2644'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/817f16ed62bc58a168417bfb5e859c2a370bab03'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/fbc72f5c645155dc2ed3573243ed20f9913e3a54'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
tags:
  - nvd
epss: 0.00186
epssPercentile: 0.07337
ingestedAt: '2026-07-06T17:44:51.334Z'
---

## Overview

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

fs/omfs: reject s_sys_blocksize smaller than OMFS_DIR_START

omfs_fill_super() rejects oversized s_sys_blocksize values (> PAGE_SIZE),
but it does not reject values smaller than OMFS_DIR_START (0x1b8 = 440).

Later, omfs_make_empty() uses

    sbi->s_sys_blocksize - OMFS_DIR_START

as the length argument to memset().  Since s_sys_blocksize is u32,
a crafted filesystem image with s_sys_blocksize < OMFS_DIR_START causes
an unsigned underflow there, wrapping to a value near 2^32.  That drives
a ~4 GiB memset() from bh->b_data + OMFS_DIR_START and overwrites kernel
memory far beyond the backing block buffer.

Add the corresponding lower-bound check alongside the existing upper-bound
check in omfs_fill_super(), so that malformed images are rejected during
superblock validation before any filesystem data is processed.

## Affected

- `linux_kernel >= 2.6.27, < 5.10.258`
- `linux_kernel >= 5.11, < 5.15.209`
- `linux_kernel >= 5.16, < 6.1.175`
- `linux_kernel >= 6.2, < 6.6.141`
- `linux_kernel >= 6.7, < 6.12.91`
- `linux_kernel >= 6.13, < 6.18.33`
- `linux_kernel >= 6.19, < 7.0.10`

## Remediation

Upgrade past the affected range:

- `linux_kernel 7.0.10`