CVE-2025-40233
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The extent map cache can become stale when extents are moved or defragmented, causing subsequent operations to see outdated…
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.15%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
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The extent map cache can become stale when extents are moved or defragmented, causing subsequent operations to see outdated extent flags.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: 1. copy_file_range() creates a reflinked extent with OCFS2_EXT_REFCOUNTED 2. ioctl(FITRIM) triggers ocfs2_move_extents() 3. __ocfs2_move_extents_range() reads and caches the extent (flags=0x2) 4. ocfs2_move_extent()/ocfs2_defrag_extent() calls __ocfs2_move_extent() which clears OCFS2_EXT_REFCOUNTED flag on disk (flags=0x0) 5. The extent map cache is not invalidated after the move 6. Later write() operations read stale cached flags (0x2) but disk has updated flags (0x0), causing a mismatch 7. 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.
- CVSS 3.1
- 7.8 HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 0.15% probability · 5th percentile
- CISA KEV
- Not listed
- Source
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
References
- https://git.kernel.org/stable/c/78a63493f8e352296dbc7cb7b3f4973105e8679e
- https://git.kernel.org/stable/c/93166bc53c0e3587058327a4121daea34b4fecd5
- https://git.kernel.org/stable/c/93b1ab422f1966b71561158e1aedce4ec100f357
- https://git.kernel.org/stable/c/a21750df2f6169af6e039a3bb4893d6c9564e48d
- https://git.kernel.org/stable/c/a7ee72286efba1d407c6f15a0528e43593fb7007
- https://git.kernel.org/stable/c/aa6a21409dd6221bb268b56bb410e031c632ff9a
- https://git.kernel.org/stable/c/bb69928ed578f881e68d26aaf1a8f6e7faab3b44
- https://git.kernel.org/stable/c/e92af7737a94a729225d2a5d180eaaa77fe0bbc1
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.