Unknown

CVE-2026-89490 — ocfs2: fix readdir position truncation on 32-bit kernels

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.

Published Sep 11, 2026 · Updated Oct 19, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP, GitHub Security Advisories · CNA: Linux

Low

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.

How the score was calculated

EPSS 0.2% (30-day exploitation probability)+1

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation

Not confirmed

Not in CISA KEV — an absence of record, not proof it is unexploited.

EPSS FIRST

0.18%

ahead of 7% of scored CVEs · Oct 22, 2026

Affects

Linux

CVSS base

—

Score not published yet.

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

Identify exposed assets running the affected vendor/product/version combinations (Linux Linux).
No fix documented in the sources: reduce exposure and monitor the vendor advisory.
Search available logs for exploit probes, errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Vendor	Product	Versions	Status	Source
Linux	Linux	≥ ccd979bdbce9fba8412beb3f1de68a9d0171b12c and < c28dc3407937aa8f225942538cd585c9b28ea65a≥ ccd979bdbce9fba8412beb3f1de68a9d0171b12c and < 94569154ba49f5f85645d2019c8e206213d8404e≥ ccd979bdbce9fba8412beb3f1de68a9d0171b12c and < 1ae7029823ae4c91664cb32eec7fb8dd5e1a337a≥ ccd979bdbce9fba8412beb3f1de68a9d0171b12c and < f9dd5cad8d09110ddff2db1fe756aae93c7552ff≥ ccd979bdbce9fba8412beb3f1de68a9d0171b12c and < 1001fb3b69a11eaa0dc7c7428f6edfa48b88997a≥ ccd979bdbce9fba8412beb3f1de68a9d0171b12c and < c0c165487a2ea5a37ddcdab4259157b7a527129c≥ ccd979bdbce9fba8412beb3f1de68a9d0171b12c and < b53e2b271eeb6040c2a4a78230c570dc41cdcfa4≥ ccd979bdbce9fba8412beb3f1de68a9d0171b12c and < a63308ab426f3a3c7e33b02c150ea59054620261 and 1 more version 2.6.16	Vulnerable	CVE Program (cve.org) e CISA ADP

EPSS over time FIRST

Oct 15, 2026 → Oct 22, 2026 · 7 reading(s) · max 0.18%

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

Not enough vector or weakness data: use the affected application’s logs as a starting point.

application logs

Timeline

What happened to this CVE, newest first.

2026
Record published
Oct 15, 2026
Affected products added · linux/linux
Oct 15, 2026 · CVE Program (cve.org) e CISA ADP
Source status changed · → Received
Oct 15, 2026 · NIST National Vulnerability Database
Record created in this database
Oct 15, 2026 · NIST National Vulnerability Database
CVE published
Sep 11, 2026 · Linux

Source activity

Repeated readings are counted rather than listed.

1× References added · Oct 19, 2026 – Oct 19, 2026
1× Official description updated · Oct 15, 2026 – Oct 15, 2026

References

10 on the record

git.kernel.org/stable/c/b53e2b271eeb6040c2a4a78230c570dc41cdcfa4
NIST National Vulnerability Database
git.kernel.org/stable/c/1001fb3b69a11eaa0dc7c7428f6edfa48b88997a
NIST National Vulnerability Database
git.kernel.org/stable/c/f9dd5cad8d09110ddff2db1fe756aae93c7552ff
NIST National Vulnerability Database
nvd.nist.gov/vuln/detail/CVE-2026-89490
GitHub Security Advisories
git.kernel.org/stable/c/a63308ab426f3a3c7e33b02c150ea59054620261
NIST National Vulnerability Database
github.com/advisories/GHSA-3jg7-r7pg-8654
GitHub Security Advisories
git.kernel.org/stable/c/c28dc3407937aa8f225942538cd585c9b28ea65a
NIST National Vulnerability Database
git.kernel.org/stable/c/c0c165487a2ea5a37ddcdab4259157b7a527129c
NIST National Vulnerability Database
git.kernel.org/stable/c/94569154ba49f5f85645d2019c8e206213d8404e
NIST National Vulnerability Database
git.kernel.org/stable/c/1ae7029823ae4c91664cb32eec7fb8dd5e1a337a
NIST National Vulnerability Database

Elsewhere on this site

Linux
every CVE for this vendor

Related CVEs (same products)

Unknown CVE-2026-99086 dm-integrity: validate the superblock on resume 9h
Unknown CVE-2026-99087 dm-integrity: fix NULL pointer dereference when the 'R' flag is used 9h
Unknown CVE-2026-99079 net/mlx5e: Prevent stale XSK buffer release on refill retry 9h
Unknown CVE-2026-99080 fs: Free any excess xarray nodes in clear_inode() 9h
Unknown CVE-2026-99081 bnxt_en: fix DMA mapping length for padded small packets 9h
Unknown CVE-2026-99082 KVM: x86: Use active memslots for the per-vCPU MMIO cache 9h

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No CVSS score published by NVD, the CNA, CISA or GitHub so far.
No fixed version, patch or mitigation documented.
No CISA SSVC assessment.
No CWE classification.
No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2026-89490 is "ocfs2: fix readdir position truncation on 32-bit kernels", rated Unknown. It affects Linux (Linux); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. EPSS 0.18% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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