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CVE-2022-50089

Estado: AnalizadaMedia (5.5)—

In the Linux kernel, the following vulnerability has been resolved:

btrfs: ensure pages are unlocked on cow_file_range() failure

There is a hung_task report on zoned btrfs like below.

https://github.com/naota/linux/issues/59

While we debug the issue, we found running fstests generic/551 on 5GB non-zoned null_blk device in the emulated zoned mode also had a similar hung issue.

Also, we can reproduce the same symptom with an error injected cow_file_range() setup.

The hang occurs when cow_file_range() fails in the middle of allocation. cow_file_range() called from do_allocation_zoned() can split the give region ([start, end]) for allocation depending on current block group usages.

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When btrfs can allocate bytes for one part of the split regions but fails for the other region (e.g. because of -ENOSPC), we return the error leaving the pages in the succeeded regions locked. Technically, this occurs only when @unlock == 0. Otherwise, we unlock the pages in an allocated region after creating an ordered extent.

Considering the callers of cow_file_range(unlock=0) won't write out the pages, we can unlock the pages on error exit from cow_file_range(). So, we can ensure all the pages except @locked_page are unlocked on error case.

In summary, cow_file_range now behaves like this:

Detalles técnicos trazas, registros y código del informe original
  [726.328648] INFO: task rocksdb:high0:11085 blocked for more than 241 seconds.
  [726.329839]       Not tainted 5.16.0-rc1+ #1
  [726.330484] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  [726.331603] task:rocksdb:high0   state:D stack:    0 pid:11085 ppid: 11082 flags:0x00000000
  [726.331608] Call Trace:
  [726.331611]  <TASK>
  [726.331614]  __schedule+0x2e5/0x9d0
  [726.331622]  schedule+0x58/0xd0
  [726.331626]  io_schedule+0x3f/0x70
  [726.331629]  __folio_lock+0x125/0x200
  [726.331634]  ? find_get_entries+0x1bc/0x240
  [726.331638]  ? filemap_invalidate_unlock_two+0x40/0x40
  [726.331642]  truncate_inode_pages_range+0x5b2/0x770
  [726.331649]  truncate_inode_pages_final+0x44/0x50
  [726.331653]  btrfs_evict_inode+0x67/0x480
  [726.331658]  evict+0xd0/0x180
  [726.331661]  iput+0x13f/0x200
  [726.331664]  do_unlinkat+0x1c0/0x2b0
  [726.331668]  __x64_sys_unlink+0x23/0x30
  [726.331670]  do_syscall_64+0x3b/0xc0
  [726.331674]  entry_SYSCALL_64_after_hwframe+0x44/0xae
  [726.331677] RIP: 0033:0x7fb9490a171b
  [726.331681] RSP: 002b:00007fb943ffac68 EFLAGS: 00000246 ORIG_RAX: 0000000000000057
  [726.331684] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fb9490a171b
  [726.331686] RDX: 00007fb943ffb040 RSI: 000055a6bbe6ec20 RDI: 00007fb94400d300
  [726.331687] RBP: 00007fb943ffad00 R08: 0000000000000000 R09: 0000000000000000
  [726.331688] R10: 0000000000000031 R11: 0000000000000246 R12: 00007fb943ffb000
  [726.331690] R13: 00007fb943ffb040 R14: 0000000000000000 R15: 00007fb943ffd260
  [726.331693]  </TASK>

- page_started == 1 (return value)
  - All the pages are unlocked. IO is started.
- unlock == 1
  - All the pages except @locked_page are unlocked in any case
- unlock == 0
  - On success, all the pages are locked for writing out them
  - On failure, all the pages except @locked_page are unlocked

CVSS

Probabilidad de explotación (EPSS)

EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).

Tecnologías afectadas (1)

CWE

Referencias

JSON original (NVD)

Mostrar
{
  "id": "CVE-2022-50089",
  "cveTags": [],
  "metrics": {
    "cvssMetricV31": [
      {
        "type": "Primary",
        "source": "nvd@nist.gov",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 5.5,
          "attackVector": "LOCAL",
          "baseSeverity": "MEDIUM",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
          "integrityImpact": "NONE",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "confidentialityImpact": "NONE"
        },
        "impactScore": 3.6,
        "exploitabilityScore": 1.8
      }
    ]
  },
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "42c011000963442ce533d92a492c4a057b2f5a46",
              "lessThan": "b367f125c80fa838eae49e3b138dc67dfc9f46ef",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "42c011000963442ce533d92a492c4a057b2f5a46",
              "lessThan": "9535ec371d741fa037e37eddc0a5b25ba82d0027",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "42c011000963442ce533d92a492c4a057b2f5a46",
              "lessThan": "e160aa87c87a9c4e0c8d1430235f715a3a91e2cd",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "42c011000963442ce533d92a492c4a057b2f5a46",
              "lessThan": "9ce7466f372d83054c7494f6b3e4b9abaf3f0355",
              "versionType": "git"
            }
          ],
          "programFiles": [
            "fs/btrfs/inode.c"
          ],
          "defaultStatus": "unaffected"
        },
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.12"
            },
            {
              "status": "unaffected",
              "version": "0",
              "lessThan": "5.12",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "5.15.61",
              "versionType": "semver",
              "lessThanOrEqual": "5.15.*"
            },
            {
              "status": "unaffected",
              "version": "5.18.18",
              "versionType": "semver",
              "lessThanOrEqual": "5.18.*"
            },
            {
              "status": "unaffected",
              "version": "5.19.2",
              "versionType": "semver",
              "lessThanOrEqual": "5.19.*"
            },
            {
              "status": "unaffected",
              "version": "6.0",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ],
          "programFiles": [
            "fs/btrfs/inode.c"
          ],
          "defaultStatus": "affected"
        }
      ]
    }
  ],
  "published": "2025-06-18T11:15:38.023",
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/9535ec371d741fa037e37eddc0a5b25ba82d0027",
      "tags": [
        "Patch"
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/9ce7466f372d83054c7494f6b3e4b9abaf3f0355",
      "tags": [
        "Patch"
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/b367f125c80fa838eae49e3b138dc67dfc9f46ef",
      "tags": [
        "Patch"
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/e160aa87c87a9c4e0c8d1430235f715a3a91e2cd",
      "tags": [
        "Patch"
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "type": "Primary",
      "source": "nvd@nist.gov",
      "description": [
        {
          "lang": "en",
          "value": "NVD-CWE-noinfo"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: ensure pages are unlocked on cow_file_range() failure\n\nThere is a hung_task report on zoned btrfs like below.\n\nhttps://github.com/naota/linux/issues/59\n\n  [726.328648] INFO: task rocksdb:high0:11085 blocked for more than 241 seconds.\n  [726.329839]       Not tainted 5.16.0-rc1+ #1\n  [726.330484] \"echo 0 > /proc/sys/kernel/hung_task_timeout_secs\" disables this message.\n  [726.331603] task:rocksdb:high0   state:D stack:    0 pid:11085 ppid: 11082 flags:0x00000000\n  [726.331608] Call Trace:\n  [726.331611]  <TASK>\n  [726.331614]  __schedule+0x2e5/0x9d0\n  [726.331622]  schedule+0x58/0xd0\n  [726.331626]  io_schedule+0x3f/0x70\n  [726.331629]  __folio_lock+0x125/0x200\n  [726.331634]  ? find_get_entries+0x1bc/0x240\n  [726.331638]  ? filemap_invalidate_unlock_two+0x40/0x40\n  [726.331642]  truncate_inode_pages_range+0x5b2/0x770\n  [726.331649]  truncate_inode_pages_final+0x44/0x50\n  [726.331653]  btrfs_evict_inode+0x67/0x480\n  [726.331658]  evict+0xd0/0x180\n  [726.331661]  iput+0x13f/0x200\n  [726.331664]  do_unlinkat+0x1c0/0x2b0\n  [726.331668]  __x64_sys_unlink+0x23/0x30\n  [726.331670]  do_syscall_64+0x3b/0xc0\n  [726.331674]  entry_SYSCALL_64_after_hwframe+0x44/0xae\n  [726.331677] RIP: 0033:0x7fb9490a171b\n  [726.331681] RSP: 002b:00007fb943ffac68 EFLAGS: 00000246 ORIG_RAX: 0000000000000057\n  [726.331684] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fb9490a171b\n  [726.331686] RDX: 00007fb943ffb040 RSI: 000055a6bbe6ec20 RDI: 00007fb94400d300\n  [726.331687] RBP: 00007fb943ffad00 R08: 0000000000000000 R09: 0000000000000000\n  [726.331688] R10: 0000000000000031 R11: 0000000000000246 R12: 00007fb943ffb000\n  [726.331690] R13: 00007fb943ffb040 R14: 0000000000000000 R15: 00007fb943ffd260\n  [726.331693]  </TASK>\n\nWhile we debug the issue, we found running fstests generic/551 on 5GB\nnon-zoned null_blk device in the emulated zoned mode also had a\nsimilar hung issue.\n\nAlso, we can reproduce the same symptom with an error injected\ncow_file_range() setup.\n\nThe hang occurs when cow_file_range() fails in the middle of\nallocation. cow_file_range() called from do_allocation_zoned() can\nsplit the give region ([start, end]) for allocation depending on\ncurrent block group usages. When btrfs can allocate bytes for one part\nof the split regions but fails for the other region (e.g. because of\n-ENOSPC), we return the error leaving the pages in the succeeded regions\nlocked. Technically, this occurs only when @unlock == 0. Otherwise, we\nunlock the pages in an allocated region after creating an ordered\nextent.\n\nConsidering the callers of cow_file_range(unlock=0) won't write out\nthe pages, we can unlock the pages on error exit from\ncow_file_range(). So, we can ensure all the pages except @locked_page\nare unlocked on error case.\n\nIn summary, cow_file_range now behaves like this:\n\n- page_started == 1 (return value)\n  - All the pages are unlocked. IO is started.\n- unlock == 1\n  - All the pages except @locked_page are unlocked in any case\n- unlock == 0\n  - On success, all the pages are locked for writing out them\n  - On failure, all the pages except @locked_page are unlocked"
    },
    {
      "lang": "es",
      "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: btrfs: garantizar que las páginas se desbloqueen en caso de fallo de cow_file_range() Hay un informe de hung_task en btrfs zonificados como el que se muestra a continuación. https://github.com/naota/linux/issues/59 [726.328648] INFORMACIÓN: la tarea rocksdb:high0:11085 se bloqueó durante más de 241 segundos. [726.329839] No contaminado 5.16.0-rc1+ #1 [726.330484] \"echo 0 &gt; /proc/sys/kernel/hung_task_timeout_secs\" deshabilita este mensaje. [726.331603] tarea:rocksdb:high0 estado:D pila: 0 pid:11085 ppid: 11082 indicadores:0x00000000 [726.331608] Seguimiento de llamadas: [726.331611]   [726.331614] __schedule+0x2e5/0x9d0 [726.331622] schedule+0x58/0xd0 [726.331626] io_schedule+0x3f/0x70 [726.331629] __folio_lock+0x125/0x200 [726.331634] ? find_get_entries+0x1bc/0x240 [726.331638] ? filemap_invalidate_unlock_two+0x40/0x40 [726.331642] truncate_inode_pages_range+0x5b2/0x770 [726.331649] truncate_inode_pages_final+0x44/0x50 [726.331653] btrfs_evict_inode+0x67/0x480 [726.331658] evict+0xd0/0x180 [726.331661] iput+0x13f/0x200 [726.331664] do_unlinkat+0x1c0/0x2b0 [726.331668] __x64_sys_unlink+0x23/0x30 [726.331670] do_syscall_64+0x3b/0xc0 [726.331674] entry_SYSCALL_64_after_hwframe+0x44/0xae [726.331677] RIP: 0033:0x7fb9490a171b [726.331681] RSP: 002b:00007fb943ffac68 EFLAGS: 00000246 ORIG_RAX: 0000000000000057 [726.331684] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fb9490a171b [726.331686] RDX: 00007fb943ffb040 RSI: 000055a6bbe6ec20 RDI: 00007fb94400d300 [726.331687] RBP: 00007fb943ffad00 R08: 0000000000000000 R09: 0000000000000000 [726.331688] R10: 0000000000000031 R11: 0000000000000246 R12: 00007fb943ffb000 [726.331690] R13: 00007fb943ffb040 R14: 0000000000000000 R15: 00007fb943ffd260 [726.331693]  Mientras depurábamos el problema, encontramos que ejecutar fstests generic/551 en un dispositivo null_blk sin zona de 5 GB en el modo de zona emulada también tenía un problema de bloqueo similar. Además, podemos reproducir el mismo síntoma con un error inyectado en la configuración de cow_file_range(). El bloqueo ocurre cuando cow_file_range() falla en medio de la asignación. cow_file_range() llamado desde do_allocation_zoned() puede dividir la región dada ([inicio, fin]) para la asignación dependiendo de los usos actuales del grupo de bloques. Cuando btrfs puede asignar bytes para una parte de las regiones divididas pero falla para la otra región (por ejemplo, debido a -ENOSPC), devolvemos el error dejando bloqueadas las páginas en las regiones exitosas. Técnicamente, esto solo ocurre cuando @unlock == 0. De lo contrario, desbloqueamos las páginas en una región asignada tras crear una extensión ordenada. Dado que quienes llaman a cow_file_range(unlock=0) no escribirán las páginas, podemos desbloquearlas al salir de cow_file_range() en caso de error. Por lo tanto, podemos asegurar que todas las páginas, excepto @locked_page, se desbloqueen en caso de error. En resumen, cow_file_range ahora se comporta así: - page_started == 1 (valor de retorno): todas las páginas están desbloqueadas. Se inicia la E/S. - unlock == 1: todas las páginas, excepto @locked_page, se desbloquean en cualquier caso. - unlock == 0: en caso de éxito, todas las páginas están bloqueadas para su escritura. - en caso de error, todas las páginas, excepto @locked_page, se desbloquean."
    }
  ],
  "lastModified": "2026-06-17T05:22:44.157",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "23E86361-3C85-4727-87EC-1E6ACE028490",
              "versionEndExcluding": "5.15.61",
              "versionStartIncluding": "5.12"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "5B42E453-8837-49D0-A5EF-03F818A6DC11",
              "versionEndExcluding": "5.18.18",
              "versionStartIncluding": "5.16"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "A1A2A5A5-4598-4D7E-BA07-4660398D6C8F",
              "versionEndExcluding": "5.19.2",
              "versionStartIncluding": "5.19"
            }
          ],
          "operator": "OR"
        }
      ]
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}