fkie_cve-2021-47492
Vulnerability from fkie_nvd
Published
2024-05-22 09:15
Modified
2025-09-29 16:35
Severity ?
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: mm, thp: bail out early in collapse_file for writeback page Currently collapse_file does not explicitly check PG_writeback, instead, page_has_private and try_to_release_page are used to filter writeback pages. This does not work for xfs with blocksize equal to or larger than pagesize, because in such case xfs has no page->private. This makes collapse_file bail out early for writeback page. Otherwise, xfs end_page_writeback will panic as follows. page:fffffe00201bcc80 refcount:0 mapcount:0 mapping:ffff0003f88c86a8 index:0x0 pfn:0x84ef32 aops:xfs_address_space_operations [xfs] ino:30000b7 dentry name:"libtest.so" flags: 0x57fffe0000008027(locked|referenced|uptodate|active|writeback) raw: 57fffe0000008027 ffff80001b48bc28 ffff80001b48bc28 ffff0003f88c86a8 raw: 0000000000000000 0000000000000000 00000000ffffffff ffff0000c3e9a000 page dumped because: VM_BUG_ON_PAGE(((unsigned int) page_ref_count(page) + 127u <= 127u)) page->mem_cgroup:ffff0000c3e9a000 ------------[ cut here ]------------ kernel BUG at include/linux/mm.h:1212! Internal error: Oops - BUG: 0 [#1] SMP Modules linked in: BUG: Bad page state in process khugepaged pfn:84ef32 xfs(E) page:fffffe00201bcc80 refcount:0 mapcount:0 mapping:0 index:0x0 pfn:0x84ef32 libcrc32c(E) rfkill(E) aes_ce_blk(E) crypto_simd(E) ... CPU: 25 PID: 0 Comm: swapper/25 Kdump: loaded Tainted: ... pstate: 60400005 (nZCv daif +PAN -UAO -TCO BTYPE=--) Call trace: end_page_writeback+0x1c0/0x214 iomap_finish_page_writeback+0x13c/0x204 iomap_finish_ioend+0xe8/0x19c iomap_writepage_end_bio+0x38/0x50 bio_endio+0x168/0x1ec blk_update_request+0x278/0x3f0 blk_mq_end_request+0x34/0x15c virtblk_request_done+0x38/0x74 [virtio_blk] blk_done_softirq+0xc4/0x110 __do_softirq+0x128/0x38c __irq_exit_rcu+0x118/0x150 irq_exit+0x1c/0x30 __handle_domain_irq+0x8c/0xf0 gic_handle_irq+0x84/0x108 el1_irq+0xcc/0x180 arch_cpu_idle+0x18/0x40 default_idle_call+0x4c/0x1a0 cpuidle_idle_call+0x168/0x1e0 do_idle+0xb4/0x104 cpu_startup_entry+0x30/0x9c secondary_start_kernel+0x104/0x180 Code: d4210000 b0006161 910c8021 94013f4d (d4210000) ---[ end trace 4a88c6a074082f8c ]--- Kernel panic - not syncing: Oops - BUG: Fatal exception in interrupt
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/5e669d8ab30ab61dec3c36e27b4711f07611e6fcPatch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/69a7fa5cb0de06c8956b040f19a7248c8c8308caPatch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/74c42e1baacf206338b1dd6b6199ac964512b5bbPatch
af854a3a-2127-422b-91ae-364da2661108https://git.kernel.org/stable/c/5e669d8ab30ab61dec3c36e27b4711f07611e6fcPatch
af854a3a-2127-422b-91ae-364da2661108https://git.kernel.org/stable/c/69a7fa5cb0de06c8956b040f19a7248c8c8308caPatch
af854a3a-2127-422b-91ae-364da2661108https://git.kernel.org/stable/c/74c42e1baacf206338b1dd6b6199ac964512b5bbPatch
Impacted products
Vendor Product Version
linux linux_kernel *
linux linux_kernel *
linux linux_kernel 5.15
linux linux_kernel 5.15
linux linux_kernel 5.15
linux linux_kernel 5.15
linux linux_kernel 5.15
linux linux_kernel 5.15
linux linux_kernel 5.15


To clipboard 

{
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "6EF3E26D-A1EF-4DE4-B0D3-23ADF141E2C5",
              "versionEndExcluding": "5.10.77",
              "versionStartIncluding": "5.4",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "2681B950-4548-4649-A9E1-4124B59FC09C",
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              "versionStartIncluding": "5.11",
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            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:5.15:rc1:*:*:*:*:*:*",
              "matchCriteriaId": "E46C74C6-B76B-4C94-A6A4-FD2FFF62D644",
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              "vulnerable": true
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            {
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              "matchCriteriaId": "AF55383D-4DF2-45DC-93F7-571F4F978EAB",
              "vulnerable": true
            },
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              "criteria": "cpe:2.3:o:linux:linux_kernel:5.15:rc5:*:*:*:*:*:*",
              "matchCriteriaId": "9E9481B2-8AA6-4CBD-B5D3-C10F51FF6D01",
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          "negate": false,
          "operator": "OR"
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      ]
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  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmm, thp: bail out early in collapse_file for writeback page\n\nCurrently collapse_file does not explicitly check PG_writeback, instead,\npage_has_private and try_to_release_page are used to filter writeback\npages.  This does not work for xfs with blocksize equal to or larger\nthan pagesize, because in such case xfs has no page-\u003eprivate.\n\nThis makes collapse_file bail out early for writeback page.  Otherwise,\nxfs end_page_writeback will panic as follows.\n\n  page:fffffe00201bcc80 refcount:0 mapcount:0 mapping:ffff0003f88c86a8 index:0x0 pfn:0x84ef32\n  aops:xfs_address_space_operations [xfs] ino:30000b7 dentry name:\"libtest.so\"\n  flags: 0x57fffe0000008027(locked|referenced|uptodate|active|writeback)\n  raw: 57fffe0000008027 ffff80001b48bc28 ffff80001b48bc28 ffff0003f88c86a8\n  raw: 0000000000000000 0000000000000000 00000000ffffffff ffff0000c3e9a000\n  page dumped because: VM_BUG_ON_PAGE(((unsigned int) page_ref_count(page) + 127u \u003c= 127u))\n  page-\u003emem_cgroup:ffff0000c3e9a000\n  ------------[ cut here ]------------\n  kernel BUG at include/linux/mm.h:1212!\n  Internal error: Oops - BUG: 0 [#1] SMP\n  Modules linked in:\n  BUG: Bad page state in process khugepaged  pfn:84ef32\n   xfs(E)\n  page:fffffe00201bcc80 refcount:0 mapcount:0 mapping:0 index:0x0 pfn:0x84ef32\n   libcrc32c(E) rfkill(E) aes_ce_blk(E) crypto_simd(E) ...\n  CPU: 25 PID: 0 Comm: swapper/25 Kdump: loaded Tainted: ...\n  pstate: 60400005 (nZCv daif +PAN -UAO -TCO BTYPE=--)\n  Call trace:\n    end_page_writeback+0x1c0/0x214\n    iomap_finish_page_writeback+0x13c/0x204\n    iomap_finish_ioend+0xe8/0x19c\n    iomap_writepage_end_bio+0x38/0x50\n    bio_endio+0x168/0x1ec\n    blk_update_request+0x278/0x3f0\n    blk_mq_end_request+0x34/0x15c\n    virtblk_request_done+0x38/0x74 [virtio_blk]\n    blk_done_softirq+0xc4/0x110\n    __do_softirq+0x128/0x38c\n    __irq_exit_rcu+0x118/0x150\n    irq_exit+0x1c/0x30\n    __handle_domain_irq+0x8c/0xf0\n    gic_handle_irq+0x84/0x108\n    el1_irq+0xcc/0x180\n    arch_cpu_idle+0x18/0x40\n    default_idle_call+0x4c/0x1a0\n    cpuidle_idle_call+0x168/0x1e0\n    do_idle+0xb4/0x104\n    cpu_startup_entry+0x30/0x9c\n    secondary_start_kernel+0x104/0x180\n  Code: d4210000 b0006161 910c8021 94013f4d (d4210000)\n  ---[ end trace 4a88c6a074082f8c ]---\n  Kernel panic - not syncing: Oops - BUG: Fatal exception in interrupt"
    },
    {
      "lang": "es",
      "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: mm, thp: rescatar temprano en el colapso_archivo para la p\u00e1gina de reescritura. Actualmente, colapso_archivo no verifica expl\u00edcitamente PG_writeback; en su lugar, page_has_private y try_to_release_page se utilizan para filtrar las p\u00e1ginas de reescritura. Esto no funciona para xfs con un tama\u00f1o de bloque igual o mayor que el tama\u00f1o de p\u00e1gina, porque en tal caso xfs no tiene p\u00e1gina-\u0026gt;privada. Esto hace que colapso_file salga anticipadamente de la p\u00e1gina de reescritura. De lo contrario, xfs end_page_writeback entrar\u00e1 en p\u00e1nico de la siguiente manera. p\u00e1gina:fffffe00201bcc80 refcount:0 mapcount:0 mapeo:ffff0003f88c86a8 \u00edndice:0x0 pfn:0x84ef32 aops:xfs_address_space_operaciones [xfs] ino:30000b7 nombre dentry:\"libtest.so\" banderas: 0x57fffe0000008027(bloqueado|referenciado| actualizaci\u00f3n|activo|reescritura) sin formato : 57fffe0000008027 ffff80001b48bc28 ffff80001b48bc28 ffff0003f88c86a8 crudo: 0000000000000000 00000000000000000 00000000ffffffff p\u00e1gina volcada porque: VM_BUG_ON_PAGE(((unsigned int) page_ref_count(page) + 127u \u0026lt;= 127u)) page-\u0026gt;mem_cgroup:ffff0000c3e9a000 ----------- -[ cortar aqu\u00ed ]------------ \u00a1ERROR del kernel en include/linux/mm.h:1212! Error interno: Ups - ERROR: 0 [#1] M\u00f3dulos SMP vinculados en: ERROR: Estado de p\u00e1gina incorrecto en el proceso khugepaged pfn:84ef32 xfs(E) page:fffffe00201bcc80 refcount:0 mapcount:0 mapeo:0 index:0x0 pfn:0x84ef32 libcrc32c(E) rfkill(E) aes_ce_blk(E) crypto_simd(E) ... CPU: 25 PID: 0 Comm: swapper/25 Kdump: cargado Contaminado: ... pstate: 60400005 (nZCv daif +PAN -UAO -TCO BTYPE=--) Seguimiento de llamadas: end_page_writeback+0x1c0/0x214 iomap_finish_page_writeback+0x13c/0x204 iomap_finish_ioend+0xe8/0x19c iomap_writepage_end_bio+0x38/0x50 bio_endio+0x168/0x1ec blk_update_request+0x278/0x 3f0 blk_mq_end_request+0x34/0x15c virtblk_request_done+0x38/0x74 [virtio_blk ] blk_done_softirq+0xc4/0x110 __do_softirq+0x128/0x38c __irq_exit_rcu+0x118/0x150 irq_exit+0x1c/0x30 __handle_domain_irq+0x8c/0xf0 gic_handle_irq+0x84/0x108 xcc/0x180 arch_cpu_idle+0x18/0x40 default_idle_call+0x4c/0x1a0 cpuidle_idle_call+0x168/ 0x1e0 do_idle+0xb4/0x104 cpu_startup_entry+0x30/0x9c second_start_kernel+0x104/0x180 C\u00f3digo: d4210000 b0006161 910c8021 94013f4d (d4210000) ---[ end trace 4a88c6a074082f 8c ]--- P\u00e1nico en el kernel - no se sincroniza: Ups - ERROR: excepci\u00f3n fatal en la interrupci\u00f3n"
    }
  ],
  "id": "CVE-2021-47492",
  "lastModified": "2025-09-29T16:35:34.680",
  "metrics": {
    "cvssMetricV31": [
      {
        "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": "2024-05-22T09:15:11.030",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/5e669d8ab30ab61dec3c36e27b4711f07611e6fc"
    },
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      "url": "https://git.kernel.org/stable/c/69a7fa5cb0de06c8956b040f19a7248c8c8308ca"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
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      "url": "https://git.kernel.org/stable/c/74c42e1baacf206338b1dd6b6199ac964512b5bb"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Patch"
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      "url": "https://git.kernel.org/stable/c/5e669d8ab30ab61dec3c36e27b4711f07611e6fc"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/69a7fa5cb0de06c8956b040f19a7248c8c8308ca"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/74c42e1baacf206338b1dd6b6199ac964512b5bb"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "NVD-CWE-noinfo"
        }
      ],
      "source": "nvd@nist.gov",
      "type": "Primary"
    }
  ]
}


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