CVE-2022-48762 (GCVE-0-2022-48762)

Vulnerability from cvelistv5 – Published: 2024-06-20 11:13 – Updated: 2026-08-05 08:52
VLAI
Title
arm64: extable: fix load_unaligned_zeropad() reg indices
Summary
In the Linux kernel, the following vulnerability has been resolved: arm64: extable: fix load_unaligned_zeropad() reg indices In ex_handler_load_unaligned_zeropad() we erroneously extract the data and addr register indices from ex->type rather than ex->data. As ex->type will contain EX_TYPE_LOAD_UNALIGNED_ZEROPAD (i.e. 4): * We'll always treat X0 as the address register, since EX_DATA_REG_ADDR is extracted from bits [9:5]. Thus, we may attempt to dereference an arbitrary address as X0 may hold an arbitrary value. * We'll always treat X4 as the data register, since EX_DATA_REG_DATA is extracted from bits [4:0]. Thus we will corrupt X4 and cause arbitrary behaviour within load_unaligned_zeropad() and its caller. Fix this by extracting both values from ex->data as originally intended. On an MTE-enabled QEMU image we are hitting the following crash: Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000 Call trace: fixup_exception+0xc4/0x108 __do_kernel_fault+0x3c/0x268 do_tag_check_fault+0x3c/0x104 do_mem_abort+0x44/0xf4 el1_abort+0x40/0x64 el1h_64_sync_handler+0x60/0xa0 el1h_64_sync+0x7c/0x80 link_path_walk+0x150/0x344 path_openat+0xa0/0x7dc do_filp_open+0xb8/0x168 do_sys_openat2+0x88/0x17c __arm64_sys_openat+0x74/0xa0 invoke_syscall+0x48/0x148 el0_svc_common+0xb8/0xf8 do_el0_svc+0x28/0x88 el0_svc+0x24/0x84 el0t_64_sync_handler+0x88/0xec el0t_64_sync+0x1b4/0x1b8 Code: f8695a69 71007d1f 540000e0 927df12a (f940014a)
Severity
7.8 (High)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
6.2 (Medium)
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
SSVC
Exploitation: none Automatable: no Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2024-06-20 13:32 UTC
CWE
Assigner
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: 753b32368705c396000f95f33c3b7018474e33ad , < 47fe7a1c5e3e011eeb4ab79f2d54a794fdd1c3eb (git)
Affected: 753b32368705c396000f95f33c3b7018474e33ad , < 3758a6c74e08bdc15ccccd6872a6ad37d165239a (git)
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Linux Linux Affected: 5.16
Unaffected: 0 , < 5.16 (semver)
Unaffected: 5.16.5 , ≤ 5.16.* (semver)
Unaffected: 5.17 , ≤ * (original_commit_for_fix)
guessed Create a notification for this product.
Show details on NVD website
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          "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: arm64: extable: corrige los \u00edndices de registro load_unaligned_zeropad() En ex_handler_load_unaligned_zeropad() extraemos err\u00f3neamente los datos y los \u00edndices de registro de direcciones de ex-\u0026gt;type en lugar de ex-\u0026gt;data. Como ex-\u0026gt;type contendr\u00e1 EX_TYPE_LOAD_UNALIGNED_ZEROPAD (es decir, 4): * Siempre trataremos a X0 como el registro de direcci\u00f3n, ya que EX_DATA_REG_ADDR se extrae de los bits [9:5]. Por lo tanto, podemos intentar eliminar la referencia a una direcci\u00f3n arbitraria ya que X0 puede tener un valor arbitrario. * Siempre trataremos a X4 como el registro de datos, ya que EX_DATA_REG_DATA se extrae de los bits [4:0]. Por lo tanto, corromperemos X4 y provocaremos un comportamiento arbitrario dentro de load_unaligned_zeropad() y su llamador. Solucione este problema extrayendo ambos valores de ex-\u0026gt;data como se pretend\u00eda originalmente. En una imagen QEMU habilitada para MTE, nos encontramos con el siguiente bloqueo: No se puede manejar la desreferencia del puntero NULL del kernel en la direcci\u00f3n virtual 0000000000000000 Rastreo de llamadas: fixup_exception+0xc4/0x108 __do_kernel_fault+0x3c/0x268 do_tag_check_fault+0x3c/0x104 do_mem_abort+0x44/0 xf4 el1_abort+ 0x40/0x64 el1h_64_sync_handler+0x60/0xa0 el1h_64_sync+0x7c/0x80 link_path_walk+0x150/0x344 path_openat+0xa0/0x7dc do_filp_open+0xb8/0x168 do_sys_openat2+0x88/0x17c __arm64_s ys_openat+0x74/0xa0 invoke_syscall+0x48/0x148 el0_svc_common+0xb8/0xf8 do_el0_svc+ 0x28/0x88 el0_svc+0x24/0x84 el0t_64_sync_handler+0x88/0xec el0t_64_sync+0x1b4/0x1b8 C\u00f3digo: f8695a69 71007d1f 540000e0 927df12a (f940014a)"
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            "value": "In the Linux kernel, the following vulnerability has been resolved:\n\narm64: extable: fix load_unaligned_zeropad() reg indices\n\nIn ex_handler_load_unaligned_zeropad() we erroneously extract the data and\naddr register indices from ex-\u003etype rather than ex-\u003edata. As ex-\u003etype will\ncontain EX_TYPE_LOAD_UNALIGNED_ZEROPAD (i.e. 4):\n * We\u0027ll always treat X0 as the address register, since EX_DATA_REG_ADDR is\n   extracted from bits [9:5]. Thus, we may attempt to dereference an\n   arbitrary address as X0 may hold an arbitrary value.\n * We\u0027ll always treat X4 as the data register, since EX_DATA_REG_DATA is\n   extracted from bits [4:0]. Thus we will corrupt X4 and cause arbitrary\n   behaviour within load_unaligned_zeropad() and its caller.\n\nFix this by extracting both values from ex-\u003edata as originally intended.\n\nOn an MTE-enabled QEMU image we are hitting the following crash:\n Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000\n Call trace:\n  fixup_exception+0xc4/0x108\n  __do_kernel_fault+0x3c/0x268\n  do_tag_check_fault+0x3c/0x104\n  do_mem_abort+0x44/0xf4\n  el1_abort+0x40/0x64\n  el1h_64_sync_handler+0x60/0xa0\n  el1h_64_sync+0x7c/0x80\n  link_path_walk+0x150/0x344\n  path_openat+0xa0/0x7dc\n  do_filp_open+0xb8/0x168\n  do_sys_openat2+0x88/0x17c\n  __arm64_sys_openat+0x74/0xa0\n  invoke_syscall+0x48/0x148\n  el0_svc_common+0xb8/0xf8\n  do_el0_svc+0x28/0x88\n  el0_svc+0x24/0x84\n  el0t_64_sync_handler+0x88/0xec\n  el0t_64_sync+0x1b4/0x1b8\n Code: f8695a69 71007d1f 540000e0 927df12a (f940014a)"
          },
          {
            "lang": "es",
            "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: arm64: extable: corrige los \u00edndices de registro load_unaligned_zeropad() En ex_handler_load_unaligned_zeropad() extraemos err\u00f3neamente los datos y los \u00edndices de registro de direcciones de ex-\u0026gt;type en lugar de ex-\u0026gt;data. Como ex-\u0026gt;type contendr\u00e1 EX_TYPE_LOAD_UNALIGNED_ZEROPAD (es decir, 4): * Siempre trataremos a X0 como el registro de direcci\u00f3n, ya que EX_DATA_REG_ADDR se extrae de los bits [9:5]. Por lo tanto, podemos intentar eliminar la referencia a una direcci\u00f3n arbitraria ya que X0 puede tener un valor arbitrario. * Siempre trataremos a X4 como el registro de datos, ya que EX_DATA_REG_DATA se extrae de los bits [4:0]. Por lo tanto, corromperemos X4 y provocaremos un comportamiento arbitrario dentro de load_unaligned_zeropad() y su llamador. Solucione este problema extrayendo ambos valores de ex-\u0026gt;data como se pretend\u00eda originalmente. En una imagen QEMU habilitada para MTE, nos encontramos con el siguiente bloqueo: No se puede manejar la desreferencia del puntero NULL del kernel en la direcci\u00f3n virtual 0000000000000000 Rastreo de llamadas: fixup_exception+0xc4/0x108 __do_kernel_fault+0x3c/0x268 do_tag_check_fault+0x3c/0x104 do_mem_abort+0x44/0 xf4 el1_abort+ 0x40/0x64 el1h_64_sync_handler+0x60/0xa0 el1h_64_sync+0x7c/0x80 link_path_walk+0x150/0x344 path_openat+0xa0/0x7dc do_filp_open+0xb8/0x168 do_sys_openat2+0x88/0x17c __arm64_s ys_openat+0x74/0xa0 invoke_syscall+0x48/0x148 el0_svc_common+0xb8/0xf8 do_el0_svc+ 0x28/0x88 el0_svc+0x24/0x84 el0t_64_sync_handler+0x88/0xec el0t_64_sync+0x1b4/0x1b8 C\u00f3digo: f8695a69 71007d1f 540000e0 927df12a (f940014a)"
          }
        ],
        "id": "CVE-2022-48762",
        "lastModified": "2026-08-04T10:17:19.960",
        "metrics": {
          "cvssMetricV31": [
            {
              "cvssData": {
                "attackComplexity": "LOW",
                "attackVector": "LOCAL",
                "availabilityImpact": "HIGH",
                "baseScore": 7.8,
                "baseSeverity": "HIGH",
                "confidentialityImpact": "HIGH",
                "integrityImpact": "HIGH",
                "privilegesRequired": "LOW",
                "scope": "UNCHANGED",
                "userInteraction": "NONE",
                "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
                "version": "3.1"
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              "impactScore": 5.9,
              "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
              "type": "Secondary"
            },
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                "attackComplexity": "LOW",
                "attackVector": "LOCAL",
                "availabilityImpact": "HIGH",
                "baseScore": 6.2,
                "baseSeverity": "MEDIUM",
                "confidentialityImpact": "NONE",
                "integrityImpact": "NONE",
                "privilegesRequired": "NONE",
                "scope": "UNCHANGED",
                "userInteraction": "NONE",
                "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
                "version": "3.1"
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              "exploitabilityScore": 2.5,
              "impactScore": 3.6,
              "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
              "type": "Secondary"
            }
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          "ssvcV203": [
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                "options": [
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                    "exploitation": "none"
                  },
                  {
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                  },
                  {
                    "technicalImpact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2024-06-20T13:32:18.518076Z",
                "version": "2.0.3"
              }
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        "published": "2024-06-20T12:15:14.287",
        "references": [
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        "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "vulnStatus": "Modified",
        "weaknesses": [
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            "description": [
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                "lang": "en",
                "value": "CWE-476"
              }
            ],
            "source": "nvd@nist.gov",
            "type": "Primary"
          }
        ]
      }
    },
    "redhat_vex": {
      "aggregate_severity": "Low",
      "current_release_date": "2026-08-04T23:00:56+00:00",
      "cve": "CVE-2022-48762",
      "id": "CVE-2022-48762",
      "initial_release_date": "2022-01-01T00:00:00+00:00",
      "product_status:known_affected": "28",
      "product_status:known_not_affected": "170",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: arm64: extable: fix load_unaligned_zeropad() reg indices",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2022/cve-2022-48762.json",
      "version": "3"
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    "suse_vex": {
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      "current_release_date": "2026-09-05T23:42:17Z",
      "cve": "CVE-2022-48762",
      "id": "CVE-2022-48762",
      "initial_release_date": "2024-06-22T04:08:53Z",
      "product_status:known_not_affected": "373",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2022-48762",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2022-48762.json",
      "version": "18"
    },
    "vulnrichment": {
      "containers": {
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            "providerMetadata": {
              "dateUpdated": "2024-08-03T15:25:01.535Z",
              "orgId": "af854a3a-2127-422b-91ae-364da2661108",
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                "url": "https://git.kernel.org/stable/c/3758a6c74e08bdc15ccccd6872a6ad37d165239a"
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            ],
            "title": "CVE Program Container"
          },
          {
            "metrics": [
              {
                "cvssV3_1": {
                  "attackComplexity": "LOW",
                  "attackVector": "LOCAL",
                  "availabilityImpact": "HIGH",
                  "baseScore": 6.2,
                  "baseSeverity": "MEDIUM",
                  "confidentialityImpact": "NONE",
                  "integrityImpact": "NONE",
                  "privilegesRequired": "NONE",
                  "scope": "UNCHANGED",
                  "userInteraction": "NONE",
                  "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
                  "version": "3.1"
                }
              },
              {
                "other": {
                  "content": {
                    "id": "CVE-2022-48762",
                    "options": [
                      {
                        "Exploitation": "none"
                      },
                      {
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                      },
                      {
                        "Technical Impact": "partial"
                      }
                    ],
                    "role": "CISA Coordinator",
                    "timestamp": "2024-06-20T13:32:18.518076Z",
                    "version": "2.0.3"
                  },
                  "type": "ssvc"
                }
              }
            ],
            "problemTypes": [
              {
                "descriptions": [
                  {
                    "description": "CWE-noinfo Not enough information",
                    "lang": "en",
                    "type": "CWE"
                  }
                ]
              }
            ],
            "providerMetadata": {
              "dateUpdated": "2024-06-20T13:32:23.025Z",
              "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
              "shortName": "CISA-ADP"
            },
            "title": "CISA ADP Vulnrichment"
          }
        ],
        "cna": {
          "affected": [
            {
              "defaultStatus": "unaffected",
              "product": "Linux",
              "programFiles": [
                "arch/arm64/mm/extable.c"
              ],
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "vendor": "Linux",
              "versions": [
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              "product": "Linux",
              "programFiles": [
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              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "vendor": "Linux",
              "versions": [
                {
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                  "versionType": "semver"
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                  "version": "5.16.5",
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                  "versionType": "original_commit_for_fix"
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            }
          ],
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              "nodes": [
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                      "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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                      "versionStartIncluding": "5.16",
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              "lang": "en",
              "value": "In the Linux kernel, the following vulnerability has been resolved:\n\narm64: extable: fix load_unaligned_zeropad() reg indices\n\nIn ex_handler_load_unaligned_zeropad() we erroneously extract the data and\naddr register indices from ex-\u003etype rather than ex-\u003edata. As ex-\u003etype will\ncontain EX_TYPE_LOAD_UNALIGNED_ZEROPAD (i.e. 4):\n * We\u0027ll always treat X0 as the address register, since EX_DATA_REG_ADDR is\n   extracted from bits [9:5]. Thus, we may attempt to dereference an\n   arbitrary address as X0 may hold an arbitrary value.\n * We\u0027ll always treat X4 as the data register, since EX_DATA_REG_DATA is\n   extracted from bits [4:0]. Thus we will corrupt X4 and cause arbitrary\n   behaviour within load_unaligned_zeropad() and its caller.\n\nFix this by extracting both values from ex-\u003edata as originally intended.\n\nOn an MTE-enabled QEMU image we are hitting the following crash:\n Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000\n Call trace:\n  fixup_exception+0xc4/0x108\n  __do_kernel_fault+0x3c/0x268\n  do_tag_check_fault+0x3c/0x104\n  do_mem_abort+0x44/0xf4\n  el1_abort+0x40/0x64\n  el1h_64_sync_handler+0x60/0xa0\n  el1h_64_sync+0x7c/0x80\n  link_path_walk+0x150/0x344\n  path_openat+0xa0/0x7dc\n  do_filp_open+0xb8/0x168\n  do_sys_openat2+0x88/0x17c\n  __arm64_sys_openat+0x74/0xa0\n  invoke_syscall+0x48/0x148\n  el0_svc_common+0xb8/0xf8\n  do_el0_svc+0x28/0x88\n  el0_svc+0x24/0x84\n  el0t_64_sync_handler+0x88/0xec\n  el0t_64_sync+0x1b4/0x1b8\n Code: f8695a69 71007d1f 540000e0 927df12a (f940014a)"
            }
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                  "lang": "en",
                  "value": "AV:L - The bug is in the arm64 exception fixup for load_unaligned_zeropad(), reached when pathname hashing faults during local syscalls such as openat\u2192link_path_walk\u2192hash_name; it is not a network-protocol entry point.\nAC:L - On the worst reasonable deployment (MTE-enabled arm64, e.g. Android), an unprivileged attacker can craft a pathname so word-at-a-time hashing crosses a tag/allocation boundary and reliably invokes the broken fixup, with no attacker-uncontrollable race.\nPR:L - Triggering requires only an unprivileged local account able to call open/stat-style path lookups; no capabilities or init-namespace root are needed.\nUI:N - The attacker invokes the vulnerable path themselves via ordinary filesystem syscalls; no separate victim action is required.\nS:U - Impact is confined to the host kernel\u2019s own privilege domain (oops or corrupted kernel register state during path walk); this is not a VM/IOMMU/sandbox boundary escape.\nC:H - The broken handler always dereferences X0 and loads an unsigned long from that address, so a non-NULL X0 yields an unintended kernel memory read; combined with X4 clobber this is a memory-safety read primitive scored as C:H.\nI:H - The handler always writes the loaded value into X4, and the fix commit explicitly notes this corrupts X4 and causes arbitrary behaviour in load_unaligned_zeropad() and its caller, which can turn corrupted pointer/state into integrity compromise.\nA:H - When X0 is NULL (common after may_lookup in link_path_walk), the fixup\u2019s own load is a NULL deref that nests into die_kernel_fault, producing a documented kernel oops/panic."
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        "cveId": "CVE-2022-48762",
        "datePublished": "2024-06-20T11:13:39.855Z",
        "dateReserved": "2024-06-20T11:09:39.060Z",
        "dateUpdated": "2026-08-05T08:52:11.000Z",
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    }
  }
}



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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

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Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.


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Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.