ocfs2: fix readdir position truncation on 32-bit kernels

Description

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.

Timeline

Scores

No CVSS score yet: neither the CNA, CISA nor NVD has scored this CVE. NVD status: Received.

EPSS (exploitation in 30 days)

0.18% · top 93% of all CVEs (12 Nov 2026)

The list uses the assigner's score when there is one, then CISA's, then NVD's: Not scored.

Affected products

• Linux · Linux

  • affected ccd979bdbce9fba8412beb3f1de68a9d0171b12c – < c28dc3407937aa8f225942538cd585c9b28ea65a
  • affected ccd979bdbce9fba8412beb3f1de68a9d0171b12c – < 94569154ba49f5f85645d2019c8e206213d8404e
  • affected ccd979bdbce9fba8412beb3f1de68a9d0171b12c – < 1ae7029823ae4c91664cb32eec7fb8dd5e1a337a
  • affected ccd979bdbce9fba8412beb3f1de68a9d0171b12c – < f9dd5cad8d09110ddff2db1fe756aae93c7552ff
  • affected ccd979bdbce9fba8412beb3f1de68a9d0171b12c – < 1001fb3b69a11eaa0dc7c7428f6edfa48b88997a
  • affected ccd979bdbce9fba8412beb3f1de68a9d0171b12c – < c0c165487a2ea5a37ddcdab4259157b7a527129c
  • affected ccd979bdbce9fba8412beb3f1de68a9d0171b12c – < b53e2b271eeb6040c2a4a78230c570dc41cdcfa4
  • affected ccd979bdbce9fba8412beb3f1de68a9d0171b12c – < a63308ab426f3a3c7e33b02c150ea59054620261

• Linux · Linux

  • affected 2.6.16
  • unaffected < 2.6.16
  • unaffected 5.10.270 – ≤ 5.10.*
  • unaffected 5.15.221 – ≤ 5.15.*
  • unaffected 6.1.188 – ≤ 6.1.*
  • unaffected 6.6.157 – ≤ 6.6.*
  • unaffected 6.12.109 – ≤ 6.12.*
  • unaffected 6.18.50 – ≤ 6.18.*
  • unaffected 7.2.4 – ≤ 7.2.*
  • unaffected 7.3 – ≤ *

Sources

The same CVE in the primary databases and aggregators, to check against.

• CVE.org record (opens in a new tab)
• CVE List JSON (GitHub) (opens in a new tab)
• NVD (opens in a new tab)
• FIRST EPSS (opens in a new tab)
• EUVD EUVD-2026-76396 (opens in a new tab)
• OSV.dev (opens in a new tab)
• GitHub Advisories (opens in a new tab)
• CIRCL Vulnerability-Lookup (opens in a new tab)

Badge for a README or a ticket

[![CVE-2026-89490](https://cveledger.app/badge/CVE-2026-89490.svg)](https://cveledger.app/cve/CVE-2026-89490)

Record last updated 19 Oct 2026, 08:47 UTC.