nvd-json-data-feeds/CVE-2021/CVE-2021-472xx/CVE-2021-47256.json

{
  "id": "CVE-2021-47256",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2024-05-21T15:15:14.380",
  "lastModified": "2024-11-21T06:35:44.143",
  "vulnStatus": "Awaiting Analysis",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmm/memory-failure: make sure wait for page writeback in memory_failure\n\nOur syzkaller trigger the \"BUG_ON(!list_empty(&inode->i_wb_list))\" in\nclear_inode:\n\n  kernel BUG at fs/inode.c:519!\n  Internal error: Oops - BUG: 0 [#1] SMP\n  Modules linked in:\n  Process syz-executor.0 (pid: 249, stack limit = 0x00000000a12409d7)\n  CPU: 1 PID: 249 Comm: syz-executor.0 Not tainted 4.19.95\n  Hardware name: linux,dummy-virt (DT)\n  pstate: 80000005 (Nzcv daif -PAN -UAO)\n  pc : clear_inode+0x280/0x2a8\n  lr : clear_inode+0x280/0x2a8\n  Call trace:\n    clear_inode+0x280/0x2a8\n    ext4_clear_inode+0x38/0xe8\n    ext4_free_inode+0x130/0xc68\n    ext4_evict_inode+0xb20/0xcb8\n    evict+0x1a8/0x3c0\n    iput+0x344/0x460\n    do_unlinkat+0x260/0x410\n    __arm64_sys_unlinkat+0x6c/0xc0\n    el0_svc_common+0xdc/0x3b0\n    el0_svc_handler+0xf8/0x160\n    el0_svc+0x10/0x218\n  Kernel panic - not syncing: Fatal exception\n\nA crash dump of this problem show that someone called __munlock_pagevec\nto clear page LRU without lock_page: do_mmap -> mmap_region -> do_munmap\n-> munlock_vma_pages_range -> __munlock_pagevec.\n\nAs a result memory_failure will call identify_page_state without\nwait_on_page_writeback.  And after truncate_error_page clear the mapping\nof this page.  end_page_writeback won't call sb_clear_inode_writeback to\nclear inode->i_wb_list.  That will trigger BUG_ON in clear_inode!\n\nFix it by checking PageWriteback too to help determine should we skip\nwait_on_page_writeback."
    },
    {
      "lang": "es",
      "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: mm/memory-failure: aseg\u00farese de esperar la reescritura de la p\u00e1gina en Memory_failure. Nuestro syzkaller activa el \"BUG_ON(!list_empty(&inode->i_wb_list))\" en clear_inode: kernel BUG en fs /inodo.c:519! Error interno: Oops - BUG: 0 [#1] M\u00f3dulos SMP vinculados en: Proceso syz-executor.0 (pid: 249, l\u00edmite de pila = 0x00000000a12409d7) CPU: 1 PID: 249 Comm: syz-executor.0 No contaminado 4.19. 95 Nombre de hardware: linux,dummy-virt (DT) pstate: 80000005 (Nzcv daif -PAN -UAO) pc: clear_inode+0x280/0x2a8 lr: clear_inode+0x280/0x2a8 Rastreo de llamadas: clear_inode+0x280/0x2a8 ext4_clear_inode+0x38/0xe8 ext4_free_inode+0x130/0xc68 ext4_evict_inode+0xb20/0xcb8 desalojar+0x1a8/0x3c0 iput+0x344/0x460 do_unlinkat+0x260/0x410 __arm64_sys_unlinkat+0x6c/0xc0 el0_svc_common+0xdc /0x3b0 el0_svc_handler+0xf8/0x160 el0_svc+0x10/0x218 P\u00e1nico del kernel: no se sincroniza : Excepci\u00f3n fatal Un volcado de memoria de este problema muestra que alguien llam\u00f3 a __munlock_pagevec para borrar la p\u00e1gina LRU sin lock_page: do_mmap -> mmap_region -> do_munmap -> munlock_vma_pages_range -> __munlock_pagevec. Como resultado, Memory_failure llamar\u00e1 a identify_page_state sin wait_on_page_writeback. Y despu\u00e9s de truncate_error_page, borre el mapeo de esta p\u00e1gina. end_page_writeback no llamar\u00e1 a sb_clear_inode_writeback para borrar inode->i_wb_list. \u00a1Eso activar\u00e1 BUG_ON en clear_inode! Solucionarlo marcando tambi\u00e9n PageWriteback para ayudar a determinar si debemos omitir wait_on_page_writeback."
    }
  ],
  "metrics": {},
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/28788dc5c70597395b6b451dae4549bbaa8e2c56",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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    {
      "url": "https://git.kernel.org/stable/c/566345aaabac853aa866f53a219c4b02a6beb527",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/6d210d547adc2218ef8b5bcf23518c5f2f1fd872",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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    {
      "url": "https://git.kernel.org/stable/c/9e379da727a7a031be9b877cde7b9c34a0fb8306",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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    {
      "url": "https://git.kernel.org/stable/c/d05267fd27a5c4f54e06daefa3035995d765ca0c",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/e8675d291ac007e1c636870db880f837a9ea112a",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/28788dc5c70597395b6b451dae4549bbaa8e2c56",
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "https://git.kernel.org/stable/c/566345aaabac853aa866f53a219c4b02a6beb527",
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "https://git.kernel.org/stable/c/6d210d547adc2218ef8b5bcf23518c5f2f1fd872",
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "https://git.kernel.org/stable/c/9e379da727a7a031be9b877cde7b9c34a0fb8306",
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "https://git.kernel.org/stable/c/d05267fd27a5c4f54e06daefa3035995d765ca0c",
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "https://git.kernel.org/stable/c/e8675d291ac007e1c636870db880f837a9ea112a",
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    }
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}