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CVE-2026-89490· NVD / CVE Program· CNA Linux

ocfs2: fix readdir position truncation on 32-bit kernels

Noroxi assessment

Priority: Monitor (action score 0/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.17% (FIRST EPSS).
  • Fixed version: Linux Linux 1001fb3b69a11eaa0dc7c7428f6edfa48b88997a, 1ae7029823ae4c91664cb32eec7fb8dd5e1a337a, 94569154ba49f5f85645d2019c8e206213d8404e.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 1001fb3b69a11eaa0dc7c7428f6edfa48b88997a, 1ae7029823ae4c91664cb32eec7fb8dd5e1a337a, 94569154ba49f5f85645d2019c8e206213d8404e or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

In the Linux kernel, the following vulnerability has been resolved: ocfs2: fix readdir position truncation on 32-bit kernels In ocfs2_dir_foreach_blk_el(), the directory cookie position is rebuilt with ctx->pos = (ctx->pos & ~(sb->s_blocksize - 1)) | offset; `ctx->pos` is loff_t (signed 64-bit), while `sb->s_blocksize` is unsigned long. On 32-bit kernels unsigned long is 32-bit, so the mask ~(sb->s_blocksize - 1) is computed as a 32-bit unsigned value (e.g. 0xfffff000 for a 4 KiB block size). In the AND expression with the 64-bit `ctx->pos`, that unsigned operand is zero-extended to 64 bits per the usual arithmetic conversions, yielding 0x00000000fffff000. The high 32 bits of `ctx->pos` are silently cleared, even though directory size is allowed to exceed 4 GiB. When readdir() crosses the 4 GiB boundary on a 32-bit kernel the position is reset back into the first 4 GiB block, making the re-validation path re-enumerate already-returned dirents indefinitely. This is ocfs2_dir_foreach_blk_el(), the extent-list readdir path taken for all non-inline directories, so a directory large enough to cross 4 GiB reaches it. This is the same class of bug that commit 3dce5bb82c97 ("exfat: Fix bitwise operation having different size") fixed in exfat, and the fix mirrors the equivalent ext4 fix in this series. Cast the operand to loff_t so the mask is 64-bit before the AND: ctx->pos = (ctx->pos & ~((loff_t)sb->s_blocksize - 1)) | offset; 64-bit kernels are unaffected.

—No exploit Fix available
Published
Sep 11, 2026
Updated
Sep 14, 2026
EPSS
0.1% · 6th percentile
CWE
—

Report tools

JSON

Action score

0

Monitor

Low priority for now.

CVSS
0 / 40 · —
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

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  • Not in KEV: no record of exploitation in the wild
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  • A fix has been released

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

—

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

  • Linux Linux

    • 2.6.16affected
    • ccd979bdbce9fba8412beb3f1de68a9d0171b12c and later · before c28dc3407937aa8f225942538cd585c9b28ea65aaffected · git
    • ccd979bdbce9fba8412beb3f1de68a9d0171b12c and later · before 94569154ba49f5f85645d2019c8e206213d8404eaffected · git
    • ccd979bdbce9fba8412beb3f1de68a9d0171b12c and later · before 1ae7029823ae4c91664cb32eec7fb8dd5e1a337aaffected · git
    • ccd979bdbce9fba8412beb3f1de68a9d0171b12c and later · before f9dd5cad8d09110ddff2db1fe756aae93c7552ffaffected · git
    • ccd979bdbce9fba8412beb3f1de68a9d0171b12c and later · before 1001fb3b69a11eaa0dc7c7428f6edfa48b88997aaffected · git
    • ccd979bdbce9fba8412beb3f1de68a9d0171b12c and later · before c0c165487a2ea5a37ddcdab4259157b7a527129caffected · git
    • ccd979bdbce9fba8412beb3f1de68a9d0171b12c and later · before b53e2b271eeb6040c2a4a78230c570dc41cdcfa4affected · git
    • ccd979bdbce9fba8412beb3f1de68a9d0171b12c and later · before a63308ab426f3a3c7e33b02c150ea59054620261affected · git
    • before 2.6.16not affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12linuxall versions—
Debian:12linux-6.12before 6.12.111-1~deb12u16.12.111-1~deb12u1
Debian:13linuxbefore 6.12.111-16.12.111-1
Debian:14linuxbefore 7.2.6-17.2.6-1

Same product

linux: all records

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    40Plan

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linux1001fb3b69a11eaa0dc7c7428f6edfa48b88997aVendor (CNA)
Linux Linux1ae7029823ae4c91664cb32eec7fb8dd5e1a337aVendor (CNA)
Linux Linux94569154ba49f5f85645d2019c8e206213d8404eVendor (CNA)
Linux Linuxa63308ab426f3a3c7e33b02c150ea59054620261Vendor (CNA)
Linux Linuxb53e2b271eeb6040c2a4a78230c570dc41cdcfa4Vendor (CNA)
Linux Linuxc0c165487a2ea5a37ddcdab4259157b7a527129cVendor (CNA)
Linux Linuxc28dc3407937aa8f225942538cd585c9b28ea65aVendor (CNA)
Linux Linuxf9dd5cad8d09110ddff2db1fe756aae93c7552ffVendor (CNA)
debian:linux6.12.111-1 · Debian:13Package registry (OSV)
debian:linux-6.126.12.111-1~deb12u1 · Debian:12Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

All national notices →

Technical details

No CVSS vector for this record, so attack conditions can't be derived.

Weakness class (CWE)

—

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (7 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records