Vulnerability-Lookup

GHSA-JRXP-W58R-G8C9

Vulnerability from github – Published: 2026-09-24 18:31 – Updated: 2026-09-24 18:31

Details

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

tty: serial: 8250: protect against NULL uart->port.dev in register

serial8250_register_8250_port() conditionally copies uart->port.dev from up->port.dev only when up->port.dev is non-NULL:

if (up->port.dev) {
    uart->port.dev = up->port.dev;
    ...
}

So if both the existing uart slot and up have a NULL ->dev, uart->port.dev remains NULL. The very next ACPI companion check then dereferences it unconditionally:

if (!has_acpi_companion(uart->port.dev)) {

has_acpi_companion() reads dev->fwnode without a NULL guard (include/linux/acpi.h), so this NULL-derefs the kernel for the remaining no-dev case rather than just skipping the mctrl_gpio_init() initialisation as intended.

smatch flags the inconsistency:

drivers/tty/serial/8250/8250_core.c:767 serial8250_register_8250_port() error: 'uart->port.dev' could be null (see line 719)

Guard the call with a NULL check so register continues to work for callers that legitimately have no parent device (legacy non-OF/non-ACPI registrations).

No functional change for callers that pass a non-NULL ->dev.

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{
  "affected": [],
  "aliases": [
    "CVE-2026-97480"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-09-24T17:17:25Z",
    "severity": null
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\ntty: serial: 8250: protect against NULL uart-\u003eport.dev in register\n\nserial8250_register_8250_port() conditionally copies uart-\u003eport.dev\nfrom up-\u003eport.dev only when up-\u003eport.dev is non-NULL:\n\n\tif (up-\u003eport.dev) {\n\t\tuart-\u003eport.dev = up-\u003eport.dev;\n\t\t...\n\t}\n\nSo if both the existing uart slot and up have a NULL -\u003edev,\nuart-\u003eport.dev remains NULL. The very next ACPI companion check\nthen dereferences it unconditionally:\n\n\tif (!has_acpi_companion(uart-\u003eport.dev)) {\n\nhas_acpi_companion() reads dev-\u003efwnode without a NULL guard\n(include/linux/acpi.h), so this NULL-derefs the kernel for the\nremaining no-dev case rather than just skipping the\nmctrl_gpio_init() initialisation as intended.\n\nsmatch flags the inconsistency:\n\n  drivers/tty/serial/8250/8250_core.c:767\n  serial8250_register_8250_port() error: \u0027uart-\u003eport.dev\u0027 could be\n  null (see line 719)\n\nGuard the call with a NULL check so register continues to work\nfor callers that legitimately have no parent device (legacy\nnon-OF/non-ACPI registrations).\n\nNo functional change for callers that pass a non-NULL -\u003edev.",
  "id": "GHSA-jrxp-w58r-g8c9",
  "modified": "2026-09-24T18:31:34Z",
  "published": "2026-09-24T18:31:34Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-97480"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/5cbab666721d974bfe033a12045d808936deaefd"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/941c9f84c9b6310f7aaa1c8c785dcc634ee33050"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}

CVE-2026-97480 (GCVE-0-2026-97480)

Vulnerability from cvelistv5 – Published: 2026-09-24 16:04 – Updated: 2026-09-28 05:30

Title

tty: serial: 8250: protect against NULL uart->port.dev in register

Summary

In the Linux kernel, the following vulnerability has been resolved: tty: serial: 8250: protect against NULL uart->port.dev in register serial8250_register_8250_port() conditionally copies uart->port.dev from up->port.dev only when up->port.dev is non-NULL: if (up->port.dev) { uart->port.dev = up->port.dev; ... } So if both the existing uart slot and up have a NULL ->dev, uart->port.dev remains NULL. The very next ACPI companion check then dereferences it unconditionally: if (!has_acpi_companion(uart->port.dev)) { has_acpi_companion() reads dev->fwnode without a NULL guard (include/linux/acpi.h), so this NULL-derefs the kernel for the remaining no-dev case rather than just skipping the mctrl_gpio_init() initialisation as intended. smatch flags the inconsistency: drivers/tty/serial/8250/8250_core.c:767 serial8250_register_8250_port() error: 'uart->port.dev' could be null (see line 719) Guard the call with a NULL check so register continues to work for callers that legitimately have no parent device (legacy non-OF/non-ACPI registrations). No functional change for callers that pass a non-NULL ->dev.

Severity

No CVSS data available.

Assigner

Linux mitre root

References

2 references

URL	Tags
https://git.kernel.org/stable/c/5cbab666721d974bf…
https://git.kernel.org/stable/c/941c9f84c9b6310f7…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 4a96895f74c9633b51427fd080ab70fa62b65bc4 , < 5cbab666721d974bfe033a12045d808936deaefd (git) Affected: 4a96895f74c9633b51427fd080ab70fa62b65bc4 , < 941c9f84c9b6310f7aaa1c8c785dcc634ee33050 (git)
Linux	Linux	Affected: 5.3 Unaffected: 0 , < 5.3 (semver) Unaffected: 6.18.53 , ≤ 6.18.* (semver) Unaffected: 7.2 , ≤ * (original_commit_for_fix)

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JSON

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/tty/serial/8250/8250_core.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "5cbab666721d974bfe033a12045d808936deaefd",
              "status": "affected",
              "version": "4a96895f74c9633b51427fd080ab70fa62b65bc4",
              "versionType": "git"
            },
            {
              "lessThan": "941c9f84c9b6310f7aaa1c8c785dcc634ee33050",
              "status": "affected",
              "version": "4a96895f74c9633b51427fd080ab70fa62b65bc4",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/tty/serial/8250/8250_core.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.3"
            },
            {
              "lessThan": "5.3",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.53",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.53",
                  "versionStartIncluding": "5.3",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2",
                  "versionStartIncluding": "5.3",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ntty: serial: 8250: protect against NULL uart-\u003eport.dev in register\n\nserial8250_register_8250_port() conditionally copies uart-\u003eport.dev\nfrom up-\u003eport.dev only when up-\u003eport.dev is non-NULL:\n\n\tif (up-\u003eport.dev) {\n\t\tuart-\u003eport.dev = up-\u003eport.dev;\n\t\t...\n\t}\n\nSo if both the existing uart slot and up have a NULL -\u003edev,\nuart-\u003eport.dev remains NULL. The very next ACPI companion check\nthen dereferences it unconditionally:\n\n\tif (!has_acpi_companion(uart-\u003eport.dev)) {\n\nhas_acpi_companion() reads dev-\u003efwnode without a NULL guard\n(include/linux/acpi.h), so this NULL-derefs the kernel for the\nremaining no-dev case rather than just skipping the\nmctrl_gpio_init() initialisation as intended.\n\nsmatch flags the inconsistency:\n\n  drivers/tty/serial/8250/8250_core.c:767\n  serial8250_register_8250_port() error: \u0027uart-\u003eport.dev\u0027 could be\n  null (see line 719)\n\nGuard the call with a NULL check so register continues to work\nfor callers that legitimately have no parent device (legacy\nnon-OF/non-ACPI registrations).\n\nNo functional change for callers that pass a non-NULL -\u003edev."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-28T05:30:10.139Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/5cbab666721d974bfe033a12045d808936deaefd"
        },
        {
          "url": "https://git.kernel.org/stable/c/941c9f84c9b6310f7aaa1c8c785dcc634ee33050"
        }
      ],
      "title": "tty: serial: 8250: protect against NULL uart-\u003eport.dev in register",
      "x_generator": {
        "engine": "bippy-1.2.0"
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  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-97480",
    "datePublished": "2026-09-24T16:04:22.893Z",
    "dateReserved": "2026-09-24T16:01:01.149Z",
    "dateUpdated": "2026-09-28T05:30:10.139Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

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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.

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The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
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GHSA-JRXP-W58R-G8C9

CVE-2026-97480 (GCVE-0-2026-97480)

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