GCVE Workshop - 22 September 2026 (14:00-18:00), Luxembourg Before The Vulnopticon Conference - Registration

FKIE_CVE-2024-57975

Vulnerability from fkie_nvd - Published: 2025-02-27 02:15 - Updated: 2026-08-04 11:22
Severity
7.8 (High) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
5.5 (Medium) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Summary
In the Linux kernel, the following vulnerability has been resolved: btrfs: do proper folio cleanup when run_delalloc_nocow() failed [BUG] With CONFIG_DEBUG_VM set, test case generic/476 has some chance to crash with the following VM_BUG_ON_FOLIO(): BTRFS error (device dm-3): cow_file_range failed, start 1146880 end 1253375 len 106496 ret -28 BTRFS error (device dm-3): run_delalloc_nocow failed, start 1146880 end 1253375 len 106496 ret -28 page: refcount:4 mapcount:0 mapping:00000000592787cc index:0x12 pfn:0x10664 aops:btrfs_aops [btrfs] ino:101 dentry name(?):"f1774" flags: 0x2fffff80004028(uptodate|lru|private|node=0|zone=2|lastcpupid=0xfffff) page dumped because: VM_BUG_ON_FOLIO(!folio_test_locked(folio)) ------------[ cut here ]------------ kernel BUG at mm/page-writeback.c:2992! Internal error: Oops - BUG: 00000000f2000800 [#1] SMP CPU: 2 UID: 0 PID: 3943513 Comm: kworker/u24:15 Tainted: G OE 6.12.0-rc7-custom+ #87 Tainted: [O]=OOT_MODULE, [E]=UNSIGNED_MODULE Hardware name: QEMU KVM Virtual Machine, BIOS unknown 2/2/2022 Workqueue: events_unbound btrfs_async_reclaim_data_space [btrfs] pc : folio_clear_dirty_for_io+0x128/0x258 lr : folio_clear_dirty_for_io+0x128/0x258 Call trace: folio_clear_dirty_for_io+0x128/0x258 btrfs_folio_clamp_clear_dirty+0x80/0xd0 [btrfs] __process_folios_contig+0x154/0x268 [btrfs] extent_clear_unlock_delalloc+0x5c/0x80 [btrfs] run_delalloc_nocow+0x5f8/0x760 [btrfs] btrfs_run_delalloc_range+0xa8/0x220 [btrfs] writepage_delalloc+0x230/0x4c8 [btrfs] extent_writepage+0xb8/0x358 [btrfs] extent_write_cache_pages+0x21c/0x4e8 [btrfs] btrfs_writepages+0x94/0x150 [btrfs] do_writepages+0x74/0x190 filemap_fdatawrite_wbc+0x88/0xc8 start_delalloc_inodes+0x178/0x3a8 [btrfs] btrfs_start_delalloc_roots+0x174/0x280 [btrfs] shrink_delalloc+0x114/0x280 [btrfs] flush_space+0x250/0x2f8 [btrfs] btrfs_async_reclaim_data_space+0x180/0x228 [btrfs] process_one_work+0x164/0x408 worker_thread+0x25c/0x388 kthread+0x100/0x118 ret_from_fork+0x10/0x20 Code: 910a8021 a90363f7 a9046bf9 94012379 (d4210000) ---[ end trace 0000000000000000 ]--- [CAUSE] The first two lines of extra debug messages show the problem is caused by the error handling of run_delalloc_nocow(). E.g. we have the following dirtied range (4K blocksize 4K page size): 0 16K 32K |//////////////////////////////////////| | Pre-allocated | And the range [0, 16K) has a preallocated extent. - Enter run_delalloc_nocow() for range [0, 16K) Which found range [0, 16K) is preallocated, can do the proper NOCOW write. - Enter fallback_to_fow() for range [16K, 32K) Since the range [16K, 32K) is not backed by preallocated extent, we have to go COW. - cow_file_range() failed for range [16K, 32K) So cow_file_range() will do the clean up by clearing folio dirty, unlock the folios. Now the folios in range [16K, 32K) is unlocked. - Enter extent_clear_unlock_delalloc() from run_delalloc_nocow() Which is called with PAGE_START_WRITEBACK to start page writeback. But folios can only be marked writeback when it's properly locked, thus this triggered the VM_BUG_ON_FOLIO(). Furthermore there is another hidden but common bug that run_delalloc_nocow() is not clearing the folio dirty flags in its error handling path. This is the common bug shared between run_delalloc_nocow() and cow_file_range(). [FIX] - Clear folio dirty for range [@start, @cur_offset) Introduce a helper, cleanup_dirty_folios(), which will find and lock the folio in the range, clear the dirty flag and start/end the writeback, with the extra handling for the @locked_folio. - Introduce a helper to clear folio dirty, start and end writeback - Introduce a helper to record the last failed COW range end This is to trace which range we should skip, to avoid double unlocking. - Skip the failed COW range for the e ---truncated---
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/2434533f1c963e7317c45880c98287e5bed98325Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/5ae72abbf91eb172ce3a838a4dc34be3c9707296Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/c2b47df81c8e20a8e8cd94f0d7df211137ae94edPatch
Impacted products
Vendor Product Version
linux linux_kernel *
linux linux_kernel *
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/btrfs/inode.c",
            "fs/btrfs/subpage.h"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "5ae72abbf91eb172ce3a838a4dc34be3c9707296",
              "status": "affected",
              "version": "17ca04aff7e6171df684b7b65804df8830eb8c15",
              "versionType": "git"
            },
            {
              "lessThan": "2434533f1c963e7317c45880c98287e5bed98325",
              "status": "affected",
              "version": "17ca04aff7e6171df684b7b65804df8830eb8c15",
              "versionType": "git"
            },
            {
              "lessThan": "c2b47df81c8e20a8e8cd94f0d7df211137ae94ed",
              "status": "affected",
              "version": "17ca04aff7e6171df684b7b65804df8830eb8c15",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "fs/btrfs/inode.c",
            "fs/btrfs/subpage.h"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "3.5"
            },
            {
              "lessThan": "3.5",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.13",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.13.*",
              "status": "unaffected",
              "version": "6.13.2",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "6.14",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "F4AD16DC-627B-4DDF-9FEE-C7ABEC63B62B",
              "versionEndExcluding": "6.12.13",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "6D4116B1-1BFD-4F23-BA84-169CC05FC5A3",
              "versionEndExcluding": "6.13.2",
              "versionStartIncluding": "6.13",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: do proper folio cleanup when run_delalloc_nocow() failed\n\n[BUG]\nWith CONFIG_DEBUG_VM set, test case generic/476 has some chance to crash\nwith the following VM_BUG_ON_FOLIO():\n\n  BTRFS error (device dm-3): cow_file_range failed, start 1146880 end 1253375 len 106496 ret -28\n  BTRFS error (device dm-3): run_delalloc_nocow failed, start 1146880 end 1253375 len 106496 ret -28\n  page: refcount:4 mapcount:0 mapping:00000000592787cc index:0x12 pfn:0x10664\n  aops:btrfs_aops [btrfs] ino:101 dentry name(?):\"f1774\"\n  flags: 0x2fffff80004028(uptodate|lru|private|node=0|zone=2|lastcpupid=0xfffff)\n  page dumped because: VM_BUG_ON_FOLIO(!folio_test_locked(folio))\n  ------------[ cut here ]------------\n  kernel BUG at mm/page-writeback.c:2992!\n  Internal error: Oops - BUG: 00000000f2000800 [#1] SMP\n  CPU: 2 UID: 0 PID: 3943513 Comm: kworker/u24:15 Tainted: G           OE      6.12.0-rc7-custom+ #87\n  Tainted: [O]=OOT_MODULE, [E]=UNSIGNED_MODULE\n  Hardware name: QEMU KVM Virtual Machine, BIOS unknown 2/2/2022\n  Workqueue: events_unbound btrfs_async_reclaim_data_space [btrfs]\n  pc : folio_clear_dirty_for_io+0x128/0x258\n  lr : folio_clear_dirty_for_io+0x128/0x258\n  Call trace:\n   folio_clear_dirty_for_io+0x128/0x258\n   btrfs_folio_clamp_clear_dirty+0x80/0xd0 [btrfs]\n   __process_folios_contig+0x154/0x268 [btrfs]\n   extent_clear_unlock_delalloc+0x5c/0x80 [btrfs]\n   run_delalloc_nocow+0x5f8/0x760 [btrfs]\n   btrfs_run_delalloc_range+0xa8/0x220 [btrfs]\n   writepage_delalloc+0x230/0x4c8 [btrfs]\n   extent_writepage+0xb8/0x358 [btrfs]\n   extent_write_cache_pages+0x21c/0x4e8 [btrfs]\n   btrfs_writepages+0x94/0x150 [btrfs]\n   do_writepages+0x74/0x190\n   filemap_fdatawrite_wbc+0x88/0xc8\n   start_delalloc_inodes+0x178/0x3a8 [btrfs]\n   btrfs_start_delalloc_roots+0x174/0x280 [btrfs]\n   shrink_delalloc+0x114/0x280 [btrfs]\n   flush_space+0x250/0x2f8 [btrfs]\n   btrfs_async_reclaim_data_space+0x180/0x228 [btrfs]\n   process_one_work+0x164/0x408\n   worker_thread+0x25c/0x388\n   kthread+0x100/0x118\n   ret_from_fork+0x10/0x20\n  Code: 910a8021 a90363f7 a9046bf9 94012379 (d4210000)\n  ---[ end trace 0000000000000000 ]---\n\n[CAUSE]\nThe first two lines of extra debug messages show the problem is caused\nby the error handling of run_delalloc_nocow().\n\nE.g. we have the following dirtied range (4K blocksize 4K page size):\n\n    0                 16K                  32K\n    |//////////////////////////////////////|\n    |  Pre-allocated  |\n\nAnd the range [0, 16K) has a preallocated extent.\n\n- Enter run_delalloc_nocow() for range [0, 16K)\n  Which found range [0, 16K) is preallocated, can do the proper NOCOW\n  write.\n\n- Enter fallback_to_fow() for range [16K, 32K)\n  Since the range [16K, 32K) is not backed by preallocated extent, we\n  have to go COW.\n\n- cow_file_range() failed for range [16K, 32K)\n  So cow_file_range() will do the clean up by clearing folio dirty,\n  unlock the folios.\n\n  Now the folios in range [16K, 32K) is unlocked.\n\n- Enter extent_clear_unlock_delalloc() from run_delalloc_nocow()\n  Which is called with PAGE_START_WRITEBACK to start page writeback.\n  But folios can only be marked writeback when it\u0027s properly locked,\n  thus this triggered the VM_BUG_ON_FOLIO().\n\nFurthermore there is another hidden but common bug that\nrun_delalloc_nocow() is not clearing the folio dirty flags in its error\nhandling path.\nThis is the common bug shared between run_delalloc_nocow() and\ncow_file_range().\n\n[FIX]\n- Clear folio dirty for range [@start, @cur_offset)\n  Introduce a helper, cleanup_dirty_folios(), which\n  will find and lock the folio in the range, clear the dirty flag and\n  start/end the writeback, with the extra handling for the\n  @locked_folio.\n\n- Introduce a helper to clear folio dirty, start and end writeback\n\n- Introduce a helper to record the last failed COW range end\n  This is to trace which range we should skip, to avoid double\n  unlocking.\n\n- Skip the failed COW range for the e\n---truncated---"
    },
    {
      "lang": "es",
      "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: btrfs: realizar una depuraci\u00f3n de folio adecuada cuando falla run_delalloc_nocow() [ERROR] Con CONFIG_DEBUG_VM establecido, el caso de prueba gen\u00e9rico/476 tiene alguna posibilidad de bloquearse con el siguiente VM_BUG_ON_FOLIO(): BTRFS error (device dm-3): cow_file_range failed, start 1146880 end 1253375 len 106496 ret -28 BTRFS error (device dm-3): run_delalloc_nocow failed, start 1146880 end 1253375 len 106496 ret -28 page: refcount:4 mapcount:0 mapping:00000000592787cc index:0x12 pfn:0x10664 aops:btrfs_aops [btrfs] ino:101 dentry name(?):\"f1774\" flags: 0x2fffff80004028(uptodate|lru|private|node=0|zone=2|lastcpupid=0xfffff) page dumped because: VM_BUG_ON_FOLIO(!folio_test_locked(folio)) ------------[ cut here ]------------ kernel BUG at mm/page-writeback.c:2992! Internal error: Oops - BUG: 00000000f2000800 [#1] SMP CPU: 2 UID: 0 PID: 3943513 Comm: kworker/u24:15 Tainted: G OE 6.12.0-rc7-custom+ #87 Tainted: [O]=OOT_MODULE, [E]=UNSIGNED_MODULE Hardware name: QEMU KVM Virtual Machine, BIOS unknown 2/2/2022 Workqueue: events_unbound btrfs_async_reclaim_data_space [btrfs] pc : folio_clear_dirty_for_io+0x128/0x258 lr : folio_clear_dirty_for_io+0x128/0x258 Call trace: folio_clear_dirty_for_io+0x128/0x258 btrfs_folio_clamp_clear_dirty+0x80/0xd0 [btrfs] __process_folios_contig+0x154/0x268 [btrfs] extent_clear_unlock_delalloc+0x5c/0x80 [btrfs] run_delalloc_nocow+0x5f8/0x760 [btrfs] btrfs_run_delalloc_range+0xa8/0x220 [btrfs] writepage_delalloc+0x230/0x4c8 [btrfs] extent_writepage+0xb8/0x358 [btrfs] extent_write_cache_pages+0x21c/0x4e8 [btrfs] btrfs_writepages+0x94/0x150 [btrfs] do_writepages+0x74/0x190 filemap_fdatawrite_wbc+0x88/0xc8 start_delalloc_inodes+0x178/0x3a8 [btrfs] btrfs_start_delalloc_roots+0x174/0x280 [btrfs] shrink_delalloc+0x114/0x280 [btrfs] flush_space+0x250/0x2f8 [btrfs] btrfs_async_reclaim_data_space+0x180/0x228 [btrfs] process_one_work+0x164/0x408 worker_thread+0x25c/0x388 kthread+0x100/0x118 ret_from_fork+0x10/0x20 Code: 910a8021 a90363f7 a9046bf9 94012379 (d4210000) ---[ end trace 0000000000000000 ]--- [CAUSE] The first two lines of extra debug messages show the problem is caused by the error handling of run_delalloc_nocow(). E.g. we have the following dirtied range (4K blocksize 4K page size): 0 16K 32K |//////////////////////////////////////| | Pre-allocated | And the range [0, 16K) has a preallocated extent. - Enter run_delalloc_nocow() for range [0, 16K) Which found range [0, 16K) is preallocated, can do the proper NOCOW write. - Enter fallback_to_fow() for range [16K, 32K) Since the range [16K, 32K) is not backed by preallocated extent, we have to go COW. - cow_file_range() failed for range [16K, 32K) So cow_file_range() will do the clean up by clearing folio dirty, unlock the folios. Now the folios in range [16K, 32K) is unlocked. - Enter extent_clear_unlock_delalloc() from run_delalloc_nocow() Which is called with PAGE_START_WRITEBACK to start page writeback. Pero los folios solo se pueden marcar como escritura diferida cuando est\u00e1n correctamente bloqueados, por lo que esto activ\u00f3 VM_BUG_ON_FOLIO(). Adem\u00e1s, hay otro error oculto pero com\u00fan: run_delalloc_nocow() no borra las banderas de folio sucio en su ruta de gesti\u00f3n de errores. Este es el error com\u00fan compartido entre run_delalloc_nocow() y cow_file_range(). [FIX] - Limpiar el folio sucio para el rango [@start, @cur_offset) Introducir un ayudante, cleanup_dirty_folios(), que encontrar\u00e1 y bloquear\u00e1 el folio en el rango, limpiar\u00e1 la bandera sucia y comenzar\u00e1/finalizar\u00e1 la escritura diferida, con el manejo adicional para @locked_folio. - Introducir un ayudante para limpiar el folio sucio, iniciar y finalizar la escritura diferida - Introducir un ayudante para registrar el \u00faltimo final del rango COW fallido Esto es para rastrear qu\u00e9 rango debemos omitir, para evitar el doble desbloqueo. - Omitir el rango COW fallido para el e ---truncado---"
    }
  ],
  "id": "CVE-2024-57975",
  "lastModified": "2026-08-04T11:22:33.390",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 7.8,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 5.9,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      },
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 5.5,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 3.6,
        "source": "nvd@nist.gov",
        "type": "Primary"
      }
    ]
  },
  "published": "2025-02-27T02:15:10.687",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/2434533f1c963e7317c45880c98287e5bed98325"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/5ae72abbf91eb172ce3a838a4dc34be3c9707296"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/c2b47df81c8e20a8e8cd94f0d7df211137ae94ed"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-459"
        }
      ],
      "source": "nvd@nist.gov",
      "type": "Primary"
    }
  ]
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.


Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.