CVE-2025-38221: Linux kernel · ext4: fix out of bounds punch offset
Source GCVE Database
Not known to be exploited · CVSS 7.1 High.
Data as of 13 Nov 2026, 19:59 UTC
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 4 Jul 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 13 Nov 2026.
What to do
AI-suggested
A fix for this vulnerability has been implemented in the Linux kernel by adding validation to prevent punching holes beyond the maximum allowed offset. Users and administrators should apply the official kernel updates that include this fix. Since this is a kernel-level vulnerability, upgrading to a patched kernel version is the recommended remediation. No alternative mitigations or workarounds are indicated.
Description
CVE-2025-38221 is a high-severity vulnerability in the Linux kernel's ext4 filesystem driver. It involves an out-of-bounds punch offset when punching holes in files, which can cause a negative length calculation in the truncate_inode_partial_folio() function. This flaw can lead to kernel crashes (BUG) and denial of service. The issue arises when the punch start offset exceeds the maximum allowed end offset. The vulnerability has been fixed by adding a check to prevent punching holes beyond the max_end boundary.
References
- nvd.nist.gov/vuln/detail/CVE-2025-38221 (opens in a new tab)
- git.kernel.org/stable/c/28b62cb58fd014338f5004170f2e3a35bf0af238 (opens in a new tab)
- git.kernel.org/stable/c/a4d60ba277ecd8a98c5a593cbc0ef2237c20a541 (opens in a new tab)
- git.kernel.org/stable/c/b5e58bcd79625423487fa3ecba8e8411b5396327 (opens in a new tab)