Vulnerability-Lookup

GHSA-2XMC-F6QC-H4H9

Vulnerability from github – Published: 2026-06-24 09:30 – Updated: 2026-06-24 09:30

Details

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

tap: fix stack info leak in tap_ioctl() SIOCGIFHWADDR

In the SIOCGIFHWADDR path, tap_ioctl() copies 16 bytes of an uninitialised on-stack struct sockaddr_storage to userspace via ifr_hwaddr, but netif_get_mac_address() only writes sa_family and dev->addr_len (6 for Ethernet) bytes, leaving sa_data[6..13] uninitialised.

Those 8 trailing bytes leak kernel stack contents; SIOCGIFHWADDR on a macvtap chardev returns kernel .text and direct-map pointers, defeating KASLR.

Initialise ss at declaration.

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{
  "affected": [],
  "aliases": [
    "CVE-2026-52937"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-06-24T08:16:23Z",
    "severity": null
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\ntap: fix stack info leak in tap_ioctl() SIOCGIFHWADDR\n\nIn the SIOCGIFHWADDR path, tap_ioctl() copies 16 bytes of an\nuninitialised on-stack struct sockaddr_storage to userspace via\nifr_hwaddr, but netif_get_mac_address() only writes sa_family and\ndev-\u003eaddr_len (6 for Ethernet) bytes, leaving sa_data[6..13] uninitialised.\n\nThose 8 trailing bytes leak kernel stack contents; SIOCGIFHWADDR on a\nmacvtap chardev returns kernel .text and direct-map pointers, defeating\nKASLR.\n\nInitialise ss at declaration.",
  "id": "GHSA-2xmc-f6qc-h4h9",
  "modified": "2026-06-24T09:30:48Z",
  "published": "2026-06-24T09:30:48Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-52937"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/05305e832be7b9d65b2b72caacf7d850b3942b2a"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/719007c3492f0f1f9e9cdbed8ac45ba45bb13eeb"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/bddc09212c24934643bd44fc794748d2bbb3b6cd"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}

CVE-2026-52937 (GCVE-0-2026-52937)

Vulnerability from cvelistv5 – Published: 2026-06-24 07:14 – Updated: 2026-06-24 07:14

Title

tap: fix stack info leak in tap_ioctl() SIOCGIFHWADDR

Summary

In the Linux kernel, the following vulnerability has been resolved: tap: fix stack info leak in tap_ioctl() SIOCGIFHWADDR In the SIOCGIFHWADDR path, tap_ioctl() copies 16 bytes of an uninitialised on-stack struct sockaddr_storage to userspace via ifr_hwaddr, but netif_get_mac_address() only writes sa_family and dev->addr_len (6 for Ethernet) bytes, leaving sa_data[6..13] uninitialised. Those 8 trailing bytes leak kernel stack contents; SIOCGIFHWADDR on a macvtap chardev returns kernel .text and direct-map pointers, defeating KASLR. Initialise ss at declaration.

Severity

No CVSS data available.

Assigner

Linux

References

3 references

URL	Tags
https://git.kernel.org/stable/c/719007c3492f0f1f9…
https://git.kernel.org/stable/c/05305e832be7b9d65…
https://git.kernel.org/stable/c/bddc09212c2493464…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 3b23a32a63219f51a5298bc55a65ecee866e79d0 , < 719007c3492f0f1f9e9cdbed8ac45ba45bb13eeb (git) Affected: 3b23a32a63219f51a5298bc55a65ecee866e79d0 , < 05305e832be7b9d65b2b72caacf7d850b3942b2a (git) Affected: 3b23a32a63219f51a5298bc55a65ecee866e79d0 , < bddc09212c24934643bd44fc794748d2bbb3b6cd (git) Affected: 176188cff67ec1aa55103647b61d02315cc38e98 (git) Affected: 1fc205d9e400f069ebf30d3faa6ec2bab2cbd7b4 (git) Affected: 4d0ae760c02c98fc78b78d3a0509896bc648ad1c (git) Affected: 5.4.103 , < 5.5 (semver) Affected: 5.10.21 , < 5.11 (semver) Affected: 5.11.4 , < 5.12 (semver)
Linux	Linux	Affected: 5.12 Unaffected: 0 , < 5.12 (semver) Unaffected: 6.18.34 , ≤ 6.18.* (semver) Unaffected: 7.0.11 , ≤ 7.0.* (semver) Unaffected: 7.1 , ≤ * (original_commit_for_fix)

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/net/tap.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "719007c3492f0f1f9e9cdbed8ac45ba45bb13eeb",
              "status": "affected",
              "version": "3b23a32a63219f51a5298bc55a65ecee866e79d0",
              "versionType": "git"
            },
            {
              "lessThan": "05305e832be7b9d65b2b72caacf7d850b3942b2a",
              "status": "affected",
              "version": "3b23a32a63219f51a5298bc55a65ecee866e79d0",
              "versionType": "git"
            },
            {
              "lessThan": "bddc09212c24934643bd44fc794748d2bbb3b6cd",
              "status": "affected",
              "version": "3b23a32a63219f51a5298bc55a65ecee866e79d0",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "176188cff67ec1aa55103647b61d02315cc38e98",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "1fc205d9e400f069ebf30d3faa6ec2bab2cbd7b4",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "4d0ae760c02c98fc78b78d3a0509896bc648ad1c",
              "versionType": "git"
            },
            {
              "lessThan": "5.5",
              "status": "affected",
              "version": "5.4.103",
              "versionType": "semver"
            },
            {
              "lessThan": "5.11",
              "status": "affected",
              "version": "5.10.21",
              "versionType": "semver"
            },
            {
              "lessThan": "5.12",
              "status": "affected",
              "version": "5.11.4",
              "versionType": "semver"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/net/tap.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.12"
            },
            {
              "lessThan": "5.12",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.34",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.0.*",
              "status": "unaffected",
              "version": "7.0.11",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.34",
                  "versionStartIncluding": "5.12",
                  "vulnerable": true
                },
                {
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                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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                  "versionStartIncluding": "5.11.4",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
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      "descriptions": [
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          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ntap: fix stack info leak in tap_ioctl() SIOCGIFHWADDR\n\nIn the SIOCGIFHWADDR path, tap_ioctl() copies 16 bytes of an\nuninitialised on-stack struct sockaddr_storage to userspace via\nifr_hwaddr, but netif_get_mac_address() only writes sa_family and\ndev-\u003eaddr_len (6 for Ethernet) bytes, leaving sa_data[6..13] uninitialised.\n\nThose 8 trailing bytes leak kernel stack contents; SIOCGIFHWADDR on a\nmacvtap chardev returns kernel .text and direct-map pointers, defeating\nKASLR.\n\nInitialise ss at declaration."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-06-24T07:14:27.305Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/719007c3492f0f1f9e9cdbed8ac45ba45bb13eeb"
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        {
          "url": "https://git.kernel.org/stable/c/05305e832be7b9d65b2b72caacf7d850b3942b2a"
        },
        {
          "url": "https://git.kernel.org/stable/c/bddc09212c24934643bd44fc794748d2bbb3b6cd"
        }
      ],
      "title": "tap: fix stack info leak in tap_ioctl() SIOCGIFHWADDR",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-52937",
    "datePublished": "2026-06-24T07:14:27.305Z",
    "dateReserved": "2026-06-09T07:44:35.370Z",
    "dateUpdated": "2026-06-24T07:14:27.305Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

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.

Action not permitted

GHSA-2XMC-F6QC-H4H9

CVE-2026-52937 (GCVE-0-2026-52937)

Tags

Sightings

Nomenclature