CVE-2022-49947

{
  "id": "CVE-2022-49947",
  "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": "577d9c05cc48c5242bcf719c06a5baf3105473ad",
              "lessThan": "81203ab7a6ef843a2b904a0a494f28c457d44d27",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "7b0163c1b07b7ff1717aa975821c40df98786ddc",
              "lessThan": "b2a97babb0a510f8921891f9e70c5a5ef33cadac",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "44e602b4e52f70f04620bbbf4fe46ecb40170bde",
              "lessThan": "1da52815d5f1b654c89044db0cdc6adce43da1f1",
              "versionType": "git"
            }
          ],
          "programFiles": [
            "drivers/android/binder_alloc.c"
          ],
          "defaultStatus": "unaffected"
        },
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.15.64",
              "lessThan": "5.15.66",
              "versionType": "semver"
            },
            {
              "status": "affected",
              "version": "5.19.6",
              "lessThan": "5.19.8",
              "versionType": "semver"
            }
          ],
          "programFiles": [
            "drivers/android/binder_alloc.c"
          ],
          "defaultStatus": "unaffected"
        }
      ]
    }
  ],
  "published": "2025-06-18T11:15:21.717",
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/1da52815d5f1b654c89044db0cdc6adce43da1f1",
      "tags": [
        "Patch"
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/81203ab7a6ef843a2b904a0a494f28c457d44d27",
      "tags": [
        "Patch"
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/b2a97babb0a510f8921891f9e70c5a5ef33cadac",
      "tags": [
        "Patch"
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "type": "Primary",
      "source": "nvd@nist.gov",
      "description": [
        {
          "lang": "en",
          "value": "CWE-476"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbinder: fix alloc->vma_vm_mm null-ptr dereference\n\nSyzbot reported a couple issues introduced by commit 44e602b4e52f\n(\"binder_alloc: add missing mmap_lock calls when using the VMA\"), in\nwhich we attempt to acquire the mmap_lock when alloc->vma_vm_mm has not\nbeen initialized yet.\n\nThis can happen if a binder_proc receives a transaction without having\npreviously called mmap() to setup the binder_proc->alloc space in [1].\nAlso, a similar issue occurs via binder_alloc_print_pages() when we try\nto dump the debugfs binder stats file in [2].\n\nSample of syzbot's crash report:\n  ==================================================================\n  KASAN: null-ptr-deref in range [0x0000000000000128-0x000000000000012f]\n  CPU: 0 PID: 3755 Comm: syz-executor229 Not tainted 6.0.0-rc1-next-20220819-syzkaller #0\n  syz-executor229[3755] cmdline: ./syz-executor2294415195\n  Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022\n  RIP: 0010:__lock_acquire+0xd83/0x56d0 kernel/locking/lockdep.c:4923\n  [...]\n  Call Trace:\n   <TASK>\n   lock_acquire kernel/locking/lockdep.c:5666 [inline]\n   lock_acquire+0x1ab/0x570 kernel/locking/lockdep.c:5631\n   down_read+0x98/0x450 kernel/locking/rwsem.c:1499\n   mmap_read_lock include/linux/mmap_lock.h:117 [inline]\n   binder_alloc_new_buf_locked drivers/android/binder_alloc.c:405 [inline]\n   binder_alloc_new_buf+0xa5/0x19e0 drivers/android/binder_alloc.c:593\n   binder_transaction+0x242e/0x9a80 drivers/android/binder.c:3199\n   binder_thread_write+0x664/0x3220 drivers/android/binder.c:3986\n   binder_ioctl_write_read drivers/android/binder.c:5036 [inline]\n   binder_ioctl+0x3470/0x6d00 drivers/android/binder.c:5323\n   vfs_ioctl fs/ioctl.c:51 [inline]\n   __do_sys_ioctl fs/ioctl.c:870 [inline]\n   __se_sys_ioctl fs/ioctl.c:856 [inline]\n   __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:856\n   do_syscall_x64 arch/x86/entry/common.c:50 [inline]\n   do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80\n   entry_SYSCALL_64_after_hwframe+0x63/0xcd\n   [...]\n  ==================================================================\n\nFix these issues by setting up alloc->vma_vm_mm pointer during open()\nand caching directly from current->mm. This guarantees we have a valid\nreference to take the mmap_lock during scenarios described above.\n\n[1] https://syzkaller.appspot.com/bug?extid=f7dc54e5be28950ac459\n[2] https://syzkaller.appspot.com/bug?extid=a75ebe0452711c9e56d9"
    },
    {
      "lang": "es",
      "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: binder: corrección de la desreferencia alloc-&gt;vma_vm_mm null-ptr. Syzbot informó de un par de problemas introducidos por el commit 44e602b4e52f (\"binder_alloc: añadir llamadas mmap_lock faltantes al usar la VMA\"), en el que se intenta adquirir mmap_lock cuando alloc-&gt;vma_vm_mm aún no se ha inicializado. Esto puede ocurrir si un binder_proc recibe una transacción sin haber llamado previamente a mmap() para configurar el espacio binder_proc-&gt;alloc en [1]. Además, se produce un problema similar mediante binder_alloc_print_pages() al intentar volcar el archivo de estadísticas de binder debugfs en [2]. Ejemplo de informe de fallos de syzbot: ======================================================================= KASAN: null-ptr-deref en el rango [0x0000000000000128-0x000000000000012f] CPU: 0 PID: 3755 Comm: syz-executor229 No contaminado 6.0.0-rc1-next-20220819-syzkaller #0 syz-executor229[3755] cmdline: ./syz-executor2294415195 Nombre del hardware: Google Google Compute Engine/Google Compute Motor, BIOS Google 22/07/2022 RIP: 0010:__lock_acquire+0xd83/0x56d0 kernel/locking/lockdep.c:4923 [...] Rastreo de llamadas:  lock_acquire kernel/locking/lockdep.c:5666 [inline] lock_acquire+0x1ab/0x570 kernel/locking/lockdep.c:5631 down_read+0x98/0x450 kernel/locking/rwsem.c:1499 mmap_read_lock include/linux/mmap_lock.h:117 [inline] binder_alloc_new_buf_locked drivers/android/binder_alloc.c:405 [inline] binder_alloc_new_buf+0xa5/0x19e0 drivers/android/binder_alloc.c:593 binder_transaction+0x242e/0x9a80 drivers/android/binder.c:3199 binder_thread_write+0x664/0x3220 drivers/android/binder.c:3986 binder_ioctl_write_read drivers/android/binder.c:5036 [inline] binder_ioctl+0x3470/0x6d00 drivers/android/binder.c:5323 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl fs/ioctl.c:856 [inline] __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:856 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd [...] ================================================================== Solucione estos problemas configurando el puntero alloc-&gt;vma_vm_mm durante la operación open() y almacenando en caché directamente desde current-&gt;mm. Esto garantiza una referencia válida para tomar mmap_lock en los escenarios descritos anteriormente.. [1] https://syzkaller.appspot.com/bug?extid=f7dc54e5be28950ac459 [2] https://syzkaller.appspot.com/bug?extid=a75ebe0452711c9e56d9 "
    }
  ],
  "lastModified": "2026-06-17T05:19:35.923",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "AFA270B6-87DD-454A-97BB-682BF1119BD5",
              "versionEndExcluding": "5.15.66",
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          "operator": "OR"
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  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}