CVE-2025-21667: Linux kernel · Infinite Loop
Source GCVE Database
Not known to be exploited · CVSS 5.5 Medium.
Data as of 30 Oct 2026, 01:09 UTC
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 31 Jan 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 29 Oct 2026.
What to do
AI-suggested
Until a fix is available, avoid performing write operations on xfs filesystems on vulnerable 32-bit kernels if possible.
Description
CVE-2025-21667 is a medium severity vulnerability in the Linux kernel affecting 32-bit systems using the xfs filesystem. The flaw involves truncation of a 64-bit offset to 32 bits in the iomap_write_delalloc_scan() function, which could cause an infinite loop during write operations. This issue arises because folio_next_index() returns an unsigned long, leading to improper handling of large file offsets on 32-bit kernels.
References
- nvd.nist.gov/vuln/detail/CVE-2025-21667 (opens in a new tab)
- git.kernel.org/stable/c/402ce16421477e27f30b57d6d1a6dc248fa3a4e4 (opens in a new tab)
- git.kernel.org/stable/c/7ca4bd6b754913910151acce00be093f03642725 (opens in a new tab)
- git.kernel.org/stable/c/91371922704c8d82049ef7c2ad974d0a2cd1174d (opens in a new tab)
- git.kernel.org/stable/c/c13094b894de289514d84b8db56d1f2931a0bade (opens in a new tab)
- lists.debian.org/debian-lts-announce/2025/03/msg00001.html (opens in a new tab)