nvd-json-data-feeds/CVE-2021/CVE-2021-474xx/CVE-2021-47492.json

{
  "id": "CVE-2021-47492",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2024-05-22T09:15:11.030",
  "lastModified": "2024-11-21T06:36:19.453",
  "vulnStatus": "Awaiting Analysis",
  "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->private.\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 <= 127u))\n  page->mem_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-&gt;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 &lt;= 127u)) page-&gt;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"
    }
  ],
  "metrics": {},
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/5e669d8ab30ab61dec3c36e27b4711f07611e6fc",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/69a7fa5cb0de06c8956b040f19a7248c8c8308ca",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/74c42e1baacf206338b1dd6b6199ac964512b5bb",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/5e669d8ab30ab61dec3c36e27b4711f07611e6fc",
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "https://git.kernel.org/stable/c/69a7fa5cb0de06c8956b040f19a7248c8c8308ca",
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "https://git.kernel.org/stable/c/74c42e1baacf206338b1dd6b6199ac964512b5bb",
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    }
  ]
}