CVE-2025-40233
BaseFortify
Publication date: 2025-12-04
Last updated on: 2025-12-04
Assigner: kernel.org
Description
Description
CVSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| linux | kernel | * |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-UNKNOWN |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
This vulnerability occurs in the Linux kernel's ocfs2 filesystem where the extent map cache is not properly cleared after extents are moved or defragmented. As a result, the cache can become stale and contain outdated extent flags. When subsequent operations read this stale cache, they encounter a mismatch between cached flags and the actual flags on disk, leading to a kernel BUG_ON error in ocfs2_refcount_cal_cow_clusters(). The issue arises specifically when copy_file_range() creates a reflinked extent, ioctl(FITRIM) triggers extent moves, and the cache is not invalidated after these moves. The fix involves clearing the extent map cache after each extent move or defragment operation to ensure fresh data is read from disk.
How can this vulnerability impact me? :
This vulnerability can cause the Linux kernel to hit a BUG_ON condition, which typically results in a kernel panic or system crash. This can lead to system instability, potential data loss, or downtime, especially on systems using the ocfs2 filesystem with operations that move or defragment extents. Therefore, it can disrupt normal system operations and affect availability.
What immediate steps should I take to mitigate this vulnerability?
Apply the patch that clears the extent map cache after each extent move or defragment operation in the ocfs2 filesystem. This fix ensures that subsequent operations read fresh extent data from disk, preventing stale cache issues that trigger the BUG_ON condition.