CVE-2022-49424

Estado: AnalizadaMedia (5.5)—

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

iommu/mediatek: Fix NULL pointer dereference when printing dev_name

When larbdev is NULL (in the case I hit, the node is incorrectly set iommus = <&iommu NUM>), it will cause device_link_add() fail and kernel crashes when we try to print dev_name(larbdev).

Let's fail the probe if a larbdev is NULL to avoid invalid inputs from dts.

It should work for normal correct setting and avoid the crash caused by my incorrect setting.

Detalles técnicos trazas, registros y código del informe original

Error log:
[   18.189042][  T301] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000050
...
[   18.344519][  T301] pstate: a0400005 (NzCv daif +PAN -UAO)
[   18.345213][  T301] pc : mtk_iommu_probe_device+0xf8/0x118 [mtk_iommu]
[   18.346050][  T301] lr : mtk_iommu_probe_device+0xd0/0x118 [mtk_iommu]
[   18.346884][  T301] sp : ffffffc00a5635e0
[   18.347392][  T301] x29: ffffffc00a5635e0 x28: ffffffd44a46c1d8
[   18.348156][  T301] x27: ffffff80c39a8000 x26: ffffffd44a80cc38
[   18.348917][  T301] x25: 0000000000000000 x24: ffffffd44a80cc38
[   18.349677][  T301] x23: ffffffd44e4da4c6 x22: ffffffd44a80cc38
[   18.350438][  T301] x21: ffffff80cecd1880 x20: 0000000000000000
[   18.351198][  T301] x19: ffffff80c439f010 x18: ffffffc00a50d0c0
[   18.351959][  T301] x17: ffffffffffffffff x16: 0000000000000004
[   18.352719][  T301] x15: 0000000000000004 x14: ffffffd44eb5d420
[   18.353480][  T301] x13: 0000000000000ad2 x12: 0000000000000003
[   18.354241][  T301] x11: 00000000fffffad2 x10: c0000000fffffad2
[   18.355003][  T301] x9 : a0d288d8d7142d00 x8 : a0d288d8d7142d00
[   18.355763][  T301] x7 : ffffffd44c2bc640 x6 : 0000000000000000
[   18.356524][  T301] x5 : 0000000000000080 x4 : 0000000000000001
[   18.357284][  T301] x3 : 0000000000000000 x2 : 0000000000000005
[   18.358045][  T301] x1 : 0000000000000000 x0 : 0000000000000000
[   18.360208][  T301] Hardware name: MT6873 (DT)
[   18.360771][  T301] Call trace:
[   18.361168][  T301]  dump_backtrace+0xf8/0x1f0
[   18.361737][  T301]  dump_stack_lvl+0xa8/0x11c
[   18.362305][  T301]  dump_stack+0x1c/0x2c
[   18.362816][  T301]  mrdump_common_die+0x184/0x40c [mrdump]
[   18.363575][  T301]  ipanic_die+0x24/0x38 [mrdump]
[   18.364230][  T301]  atomic_notifier_call_chain+0x128/0x2b8
[   18.364937][  T301]  die+0x16c/0x568
[   18.365394][  T301]  __do_kernel_fault+0x1e8/0x214
[   18.365402][  T301]  do_page_fault+0xb8/0x678
[   18.366934][  T301]  do_translation_fault+0x48/0x64
[   18.368645][  T301]  do_mem_abort+0x68/0x148
[   18.368652][  T301]  el1_abort+0x40/0x64
[   18.368660][  T301]  el1h_64_sync_handler+0x54/0x88
[   18.368668][  T301]  el1h_64_sync+0x68/0x6c
[   18.368673][  T301]  mtk_iommu_probe_device+0xf8/0x118 [mtk_iommu]
...

CVSS

Versión: 3.1
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Puntuación base: 5.5

Probabilidad de explotación (EPSS)

Probabilidad de explotación en los próximos 30 días: 0.27%
Percentil entre todas las CVEs puntuadas: 17
Fecha de la puntuación: 5/10/2026

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)

Linux — Linux Kernel

CWE

CWE-476

Referencias

JSON original (NVD)

Mostrar

{
  "id": "CVE-2022-49424",
  "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": "77fbe028d5a3f7fc6060c4454ead9510533acd1e",
              "lessThan": "c3c2734e28d7fac50228c4d2b8896e8695adf304",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "18ea450ed1b60c1bb336f5efe874f61909ce7bec",
              "lessThan": "e9c63c0f73a1bbfd02624f5eae7e881df8b6830f",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "635319a4a7444ca97124d781cd96deb277ff4d40",
              "lessThan": "8837c2682b9b2eed83e6212bcf79850c593a6fee",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "635319a4a7444ca97124d781cd96deb277ff4d40",
              "lessThan": "de78657e16f41417da9332f09c2d67d100096939",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "b7bf68272b6ae7c469854e2e054db1db1d158999",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "5.15.33",
              "lessThan": "5.15.46",
              "versionType": "semver"
            },
            {
              "status": "affected",
              "version": "5.17.2",
              "lessThan": "5.17.14",
              "versionType": "semver"
            },
            {
              "status": "affected",
              "version": "5.16.19",
              "lessThan": "5.17",
              "versionType": "semver"
            }
          ],
          "programFiles": [
            "drivers/iommu/mtk_iommu.c",
            "drivers/iommu/mtk_iommu_v1.c"
          ],
          "defaultStatus": "unaffected"
        },
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.18"
            },
            {
              "status": "unaffected",
              "version": "0",
              "lessThan": "5.18",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "5.15.46",
              "versionType": "semver",
              "lessThanOrEqual": "5.15.*"
            },
            {
              "status": "unaffected",
              "version": "5.17.14",
              "versionType": "semver",
              "lessThanOrEqual": "5.17.*"
            },
            {
              "status": "unaffected",
              "version": "5.18.3",
              "versionType": "semver",
              "lessThanOrEqual": "5.18.*"
            },
            {
              "status": "unaffected",
              "version": "5.19",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ],
          "programFiles": [
            "drivers/iommu/mtk_iommu.c",
            "drivers/iommu/mtk_iommu_v1.c"
          ],
          "defaultStatus": "affected"
        }
      ]
    }
  ],
  "published": "2025-02-26T07:01:18.880",
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/8837c2682b9b2eed83e6212bcf79850c593a6fee",
      "tags": [
        "Patch"
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/c3c2734e28d7fac50228c4d2b8896e8695adf304",
      "tags": [
        "Patch"
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/de78657e16f41417da9332f09c2d67d100096939",
      "tags": [
        "Patch"
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/e9c63c0f73a1bbfd02624f5eae7e881df8b6830f",
      "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\niommu/mediatek: Fix NULL pointer dereference when printing dev_name\n\nWhen larbdev is NULL (in the case I hit, the node is incorrectly set\niommus = <&iommu NUM>), it will cause device_link_add() fail and\nkernel crashes when we try to print dev_name(larbdev).\n\nLet's fail the probe if a larbdev is NULL to avoid invalid inputs from\ndts.\n\nIt should work for normal correct setting and avoid the crash caused\nby my incorrect setting.\n\nError log:\n[   18.189042][  T301] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000050\n...\n[   18.344519][  T301] pstate: a0400005 (NzCv daif +PAN -UAO)\n[   18.345213][  T301] pc : mtk_iommu_probe_device+0xf8/0x118 [mtk_iommu]\n[   18.346050][  T301] lr : mtk_iommu_probe_device+0xd0/0x118 [mtk_iommu]\n[   18.346884][  T301] sp : ffffffc00a5635e0\n[   18.347392][  T301] x29: ffffffc00a5635e0 x28: ffffffd44a46c1d8\n[   18.348156][  T301] x27: ffffff80c39a8000 x26: ffffffd44a80cc38\n[   18.348917][  T301] x25: 0000000000000000 x24: ffffffd44a80cc38\n[   18.349677][  T301] x23: ffffffd44e4da4c6 x22: ffffffd44a80cc38\n[   18.350438][  T301] x21: ffffff80cecd1880 x20: 0000000000000000\n[   18.351198][  T301] x19: ffffff80c439f010 x18: ffffffc00a50d0c0\n[   18.351959][  T301] x17: ffffffffffffffff x16: 0000000000000004\n[   18.352719][  T301] x15: 0000000000000004 x14: ffffffd44eb5d420\n[   18.353480][  T301] x13: 0000000000000ad2 x12: 0000000000000003\n[   18.354241][  T301] x11: 00000000fffffad2 x10: c0000000fffffad2\n[   18.355003][  T301] x9 : a0d288d8d7142d00 x8 : a0d288d8d7142d00\n[   18.355763][  T301] x7 : ffffffd44c2bc640 x6 : 0000000000000000\n[   18.356524][  T301] x5 : 0000000000000080 x4 : 0000000000000001\n[   18.357284][  T301] x3 : 0000000000000000 x2 : 0000000000000005\n[   18.358045][  T301] x1 : 0000000000000000 x0 : 0000000000000000\n[   18.360208][  T301] Hardware name: MT6873 (DT)\n[   18.360771][  T301] Call trace:\n[   18.361168][  T301]  dump_backtrace+0xf8/0x1f0\n[   18.361737][  T301]  dump_stack_lvl+0xa8/0x11c\n[   18.362305][  T301]  dump_stack+0x1c/0x2c\n[   18.362816][  T301]  mrdump_common_die+0x184/0x40c [mrdump]\n[   18.363575][  T301]  ipanic_die+0x24/0x38 [mrdump]\n[   18.364230][  T301]  atomic_notifier_call_chain+0x128/0x2b8\n[   18.364937][  T301]  die+0x16c/0x568\n[   18.365394][  T301]  __do_kernel_fault+0x1e8/0x214\n[   18.365402][  T301]  do_page_fault+0xb8/0x678\n[   18.366934][  T301]  do_translation_fault+0x48/0x64\n[   18.368645][  T301]  do_mem_abort+0x68/0x148\n[   18.368652][  T301]  el1_abort+0x40/0x64\n[   18.368660][  T301]  el1h_64_sync_handler+0x54/0x88\n[   18.368668][  T301]  el1h_64_sync+0x68/0x6c\n[   18.368673][  T301]  mtk_iommu_probe_device+0xf8/0x118 [mtk_iommu]\n..."
    },
    {
      "lang": "es",
      "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: iommu/mediatek: Arreglar la desreferencia del puntero NULL al imprimir dev_name Cuando larbdev es NULL (en el caso que encontré, el nodo está configurado incorrectamente iommus = &lt;&amp;iommu NUM&gt;), provocará un error en device_link_add() y el kernel se bloquea cuando intentamos imprimir dev_name(larbdev). Hagamos que falle la sonda si un larbdev es NULL para evitar entradas no válidas de dts. Debería funcionar para una configuración correcta normal y evitar el bloqueo causado por mi configuración incorrecta. Registro de errores: [18.189042][T301] No se puede manejar la desreferencia del puntero NULL del kernel en la dirección virtual 0000000000000050 ... [ 18.344519][ T301] pstate: a0400005 (NzCv daif +PAN -UAO) [ 18.345213][ T301] pc : mtk_iommu_probe_device+0xf8/0x118 [mtk_iommu] [ 18.346050][ T301] lr : mtk_iommu_probe_device+0xd0/0x118 [mtk_iommu] [ 18.346884][ T301] sp : ffffffc00a5635e0 [ 18.347392][ T301] x29: ffffffc00a5635e0 x28: ffffffd44a46c1d8 [ 18.348156][ T301] x27: ffffff80c39a8000 x26: ffffffd44a80cc38 [ 18.348917][ T301] x25: 0000000000000000 x24: ffffffd44a80cc38 [ 18.349677][ T301] x23: ffffffd44e4da4c6 x22: ffffffd44a80cc38 [ 18.350438][ T301] x21: ffffff80cecd1880 x20: 0000000000000000 [ 18.351198][ T301] x19: ffffff80c439f010 x18: ffffffc00a50d0c0 [ 18.351959][ T301] x17: ffffffffffffffff x16: 0000000000000004 [ 18.352719][ T301] x15: 0000000000000004 x14: ffffffd44eb5d420 [ 18.353480][ T301] x13: 0000000000000ad2 x12: 0000000000000003 [ 18.354241][ T301] x11: 00000000fffffad2 x10: c0000000fffffad2 [ 18.355003][ T301] x9 : a0d288d8d7142d00 x8 : a0d288d8d7142d00 [ 18.355763][ T301] x7 : ffffffd44c2bc640 x6 : 0000000000000000 [ 18.356524][ T301] x5 : 0000000000000080 x4 : 0000000000000001 [ 18.357284][ T301] x3 : 0000000000000000 x2 : 0000000000000005 [ 18.358045][ T301] x1 : 0000000000000000 x0 : 0000000000000000 [ 18.360208][ T301] Hardware name: MT6873 (DT) [ 18.360771][ T301] Call trace: [ 18.361168][ T301] dump_backtrace+0xf8/0x1f0 [ 18.361737][ T301] dump_stack_lvl+0xa8/0x11c [ 18.362305][ T301] dump_stack+0x1c/0x2c [ 18.362816][ T301] mrdump_common_die+0x184/0x40c [mrdump] [ 18.363575][ T301] ipanic_die+0x24/0x38 [mrdump] [ 18.364230][ T301] atomic_notifier_call_chain+0x128/0x2b8 [ 18.364937][ T301] die+0x16c/0x568 [ 18.365394][ T301] __do_kernel_fault+0x1e8/0x214 [ 18.365402][ T301] do_page_fault+0xb8/0x678 [ 18.366934][ T301] do_translation_fault+0x48/0x64 [ 18.368645][ T301] do_mem_abort+0x68/0x148 [ 18.368652][ T301] el1_abort+0x40/0x64 [ 18.368660][ T301] el1h_64_sync_handler+0x54/0x88 [ 18.368668][ T301] el1h_64_sync+0x68/0x6c [ 18.368673][ T301] mtk_iommu_probe_device+0xf8/0x118 [mtk_iommu] ... "
    }
  ],
  "lastModified": "2026-06-17T05:18:00.723",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "24166EC9-810C-49CA-B9C8-F22E779CA9A3",
              "versionEndExcluding": "5.15.46",
              "versionStartIncluding": "5.15.33"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "D4ED89FC-18EE-445F-8FE2-A2B6A5F9BB13",
              "versionEndExcluding": "5.17",
              "versionStartIncluding": "5.16.19"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "E9FB70EE-3E5E-4DE4-ADA4-96A55A0154D0",
              "versionEndExcluding": "5.17.14",
              "versionStartIncluding": "5.17.2"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "8E122216-2E9E-4B3E-B7B8-D575A45BA3C2",
              "versionEndExcluding": "5.18.3",
              "versionStartIncluding": "5.18"
            }
          ],
          "operator": "OR"
        }
      ]
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}