Summary
In the Linux kernel, the following vulnerability has been resolved: ocfs2: clear extent cache...
In the Linux kernel, the following vulnerability has been resolved:
ocfs2: clear extent cache after moving/defragmenting extents
The extent map cache can become stale when extents are moved or
defragmented, causing subsequent operations to see outdated extent flags.
This triggers a BUG_ON in ocfs2_refcount_cal_cow_clusters().
The problem occurs when:
- copy_file_range() creates a reflinked extent with OCFS2_EXT_REFCOUNTED
- ioctl(FITRIM) triggers ocfs2_move_extents()
- __ocfs2_move_extents_range() reads and caches the extent (flags=0x2)
- ocfs2_move_extent()/ocfs2_defrag_extent() calls __ocfs2_move_extent()
which clears OCFS2_EXT_REFCOUNTED flag on disk (flags=0x0) - The extent map cache is not invalidated after the move
- Later write() operations read stale cached flags (0x2) but disk has
updated flags (0x0), causing a mismatch - BUG_ON(!(rec->e_flags & OCFS2_EXT_REFCOUNTED)) triggers
Fix by clearing the extent map cache after each extent move/defrag
operation in __ocfs2_move_extents_range(). This ensures subsequent
operations read fresh extent data from disk.
Impact
CVE-2025-40233 has a CVSS score of 7.8 (High). The vector is requires local access, low privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. No fixed version is listed yet, so configuration controls and monitoring matter more in the interim.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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Frequently Asked Questions
- What is CVE-2025-40233? CVE-2025-40233 is a high-severity security vulnerability. No fixed version is listed yet.
- How severe is CVE-2025-40233? CVE-2025-40233 has a CVSS score of 7.8 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Is there a fix for CVE-2025-40233? No fixed version is listed for CVE-2025-40233 yet. Monitor the advisory for updates and apply mitigations in the interim.
- Is CVE-2025-40233 exploitable, and should I be worried? Whether CVE-2025-40233 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2025-40233 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.