ghsa-pmpf-32ww-gfmp
Vulnerability from github
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The extent map cache can become stale when extents are moved or defragmented, causing subsequent operations to see outdated extent flags.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.
{
"affected": [],
"aliases": [
"CVE-2025-40233"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-12-04T16:16:16Z",
"severity": null
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nocfs2: clear extent cache after moving/defragmenting extents\n\nThe extent map cache can become stale when extents are moved or\ndefragmented, causing subsequent operations to see outdated extent flags. \nThis triggers a BUG_ON in ocfs2_refcount_cal_cow_clusters().\n\nThe problem occurs when:\n1. copy_file_range() creates a reflinked extent with OCFS2_EXT_REFCOUNTED\n2. ioctl(FITRIM) triggers ocfs2_move_extents()\n3. __ocfs2_move_extents_range() reads and caches the extent (flags=0x2)\n4. ocfs2_move_extent()/ocfs2_defrag_extent() calls __ocfs2_move_extent()\n which clears OCFS2_EXT_REFCOUNTED flag on disk (flags=0x0)\n5. The extent map cache is not invalidated after the move\n6. Later write() operations read stale cached flags (0x2) but disk has\n updated flags (0x0), causing a mismatch\n7. BUG_ON(!(rec-\u003ee_flags \u0026 OCFS2_EXT_REFCOUNTED)) triggers\n\nFix by clearing the extent map cache after each extent move/defrag\noperation in __ocfs2_move_extents_range(). This ensures subsequent\noperations read fresh extent data from disk.",
"id": "GHSA-pmpf-32ww-gfmp",
"modified": "2025-12-04T18:30:52Z",
"published": "2025-12-04T18:30:52Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-40233"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/78a63493f8e352296dbc7cb7b3f4973105e8679e"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/93166bc53c0e3587058327a4121daea34b4fecd5"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/93b1ab422f1966b71561158e1aedce4ec100f357"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/a21750df2f6169af6e039a3bb4893d6c9564e48d"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/a7ee72286efba1d407c6f15a0528e43593fb7007"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/aa6a21409dd6221bb268b56bb410e031c632ff9a"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/bb69928ed578f881e68d26aaf1a8f6e7faab3b44"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/e92af7737a94a729225d2a5d180eaaa77fe0bbc1"
}
],
"schema_version": "1.4.0",
"severity": []
}
Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.