Vulnerability-Lookup

GHSA-G4Q8-M3PW-QHVV

Vulnerability from github – Published: 2026-05-27 15:33 – Updated: 2026-05-27 15:33

Details

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

apparmor: fix NULL pointer dereference in __unix_needs_revalidation

When receiving file descriptors via SCM_RIGHTS, both the socket pointer and the socket's sk pointer can be NULL during socket setup or teardown, causing NULL pointer dereferences in __unix_needs_revalidation().

This is a regression in AppArmor 5.0.0 (kernel 6.17+) where the new __unix_needs_revalidation() function was added without proper NULL checks.

The crash manifests as: BUG: kernel NULL pointer dereference, address: 0x0000000000000018 RIP: aa_file_perm+0xb7/0x3b0 (or +0xbe/0x3b0, +0xc0/0x3e0) Call Trace: apparmor_file_receive+0x42/0x80 security_file_receive+0x2e/0x50 receive_fd+0x1d/0xf0 scm_detach_fds+0xad/0x1c0

The function dereferences sock->sk->sk_family without checking if either sock or sock->sk is NULL first.

Add NULL checks for both sock and sock->sk before accessing sk_family.

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{
  "affected": [],
  "aliases": [
    "CVE-2026-45966"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-05-27T14:17:13Z",
    "severity": null
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\napparmor: fix NULL pointer dereference in __unix_needs_revalidation\n\nWhen receiving file descriptors via SCM_RIGHTS, both the socket pointer\nand the socket\u0027s sk pointer can be NULL during socket setup or teardown,\ncausing NULL pointer dereferences in __unix_needs_revalidation().\n\nThis is a regression in AppArmor 5.0.0 (kernel 6.17+) where the new\n__unix_needs_revalidation() function was added without proper NULL checks.\n\nThe crash manifests as:\n  BUG: kernel NULL pointer dereference, address: 0x0000000000000018\n  RIP: aa_file_perm+0xb7/0x3b0 (or +0xbe/0x3b0, +0xc0/0x3e0)\n  Call Trace:\n   apparmor_file_receive+0x42/0x80\n   security_file_receive+0x2e/0x50\n   receive_fd+0x1d/0xf0\n   scm_detach_fds+0xad/0x1c0\n\nThe function dereferences sock-\u003esk-\u003esk_family without checking if either\nsock or sock-\u003esk is NULL first.\n\nAdd NULL checks for both sock and sock-\u003esk before accessing sk_family.",
  "id": "GHSA-g4q8-m3pw-qhvv",
  "modified": "2026-05-27T15:33:18Z",
  "published": "2026-05-27T15:33:18Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-45966"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/e2938ad00b21340c0362562dfedd7cfec0554d67"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/e85bc9101afc4202aa2269967ce9d3ffbecd0994"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/fea017a7f6abe179decf575a2d8464c74edb3964"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}

CVE-2026-45966 (GCVE-0-2026-45966)

Vulnerability from cvelistv5 – Published: 2026-05-27 12:18 – Updated: 2026-05-27 12:18

Title

apparmor: fix NULL pointer dereference in __unix_needs_revalidation

Summary

In the Linux kernel, the following vulnerability has been resolved: apparmor: fix NULL pointer dereference in __unix_needs_revalidation When receiving file descriptors via SCM_RIGHTS, both the socket pointer and the socket's sk pointer can be NULL during socket setup or teardown, causing NULL pointer dereferences in __unix_needs_revalidation(). This is a regression in AppArmor 5.0.0 (kernel 6.17+) where the new __unix_needs_revalidation() function was added without proper NULL checks. The crash manifests as: BUG: kernel NULL pointer dereference, address: 0x0000000000000018 RIP: aa_file_perm+0xb7/0x3b0 (or +0xbe/0x3b0, +0xc0/0x3e0) Call Trace: apparmor_file_receive+0x42/0x80 security_file_receive+0x2e/0x50 receive_fd+0x1d/0xf0 scm_detach_fds+0xad/0x1c0 The function dereferences sock->sk->sk_family without checking if either sock or sock->sk is NULL first. Add NULL checks for both sock and sock->sk before accessing sk_family.

Severity

No CVSS data available.

Assigner

Linux

References

3 references

URL	Tags
https://git.kernel.org/stable/c/fea017a7f6abe179d…
https://git.kernel.org/stable/c/e85bc9101afc4202a…
https://git.kernel.org/stable/c/e2938ad00b21340c0…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 88fec3526e84123997ecebd6bb6778eb4ce779b7 , < fea017a7f6abe179decf575a2d8464c74edb3964 (git) Affected: 88fec3526e84123997ecebd6bb6778eb4ce779b7 , < e85bc9101afc4202aa2269967ce9d3ffbecd0994 (git) Affected: 88fec3526e84123997ecebd6bb6778eb4ce779b7 , < e2938ad00b21340c0362562dfedd7cfec0554d67 (git)
Linux	Linux	Affected: 6.17 Unaffected: 0 , < 6.17 (semver) Unaffected: 6.18.14 , ≤ 6.18.* (semver) Unaffected: 6.19.4 , ≤ 6.19.* (semver) Unaffected: 7.0 , ≤ * (original_commit_for_fix)

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "security/apparmor/file.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "fea017a7f6abe179decf575a2d8464c74edb3964",
              "status": "affected",
              "version": "88fec3526e84123997ecebd6bb6778eb4ce779b7",
              "versionType": "git"
            },
            {
              "lessThan": "e85bc9101afc4202aa2269967ce9d3ffbecd0994",
              "status": "affected",
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              "versionType": "git"
            },
            {
              "lessThan": "e2938ad00b21340c0362562dfedd7cfec0554d67",
              "status": "affected",
              "version": "88fec3526e84123997ecebd6bb6778eb4ce779b7",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "security/apparmor/file.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.17"
            },
            {
              "lessThan": "6.17",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.14",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.19.*",
              "status": "unaffected",
              "version": "6.19.4",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.0",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.14",
                  "versionStartIncluding": "6.17",
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                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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                  "versionStartIncluding": "6.17",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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                }
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      "descriptions": [
        {
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          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\napparmor: fix NULL pointer dereference in __unix_needs_revalidation\n\nWhen receiving file descriptors via SCM_RIGHTS, both the socket pointer\nand the socket\u0027s sk pointer can be NULL during socket setup or teardown,\ncausing NULL pointer dereferences in __unix_needs_revalidation().\n\nThis is a regression in AppArmor 5.0.0 (kernel 6.17+) where the new\n__unix_needs_revalidation() function was added without proper NULL checks.\n\nThe crash manifests as:\n  BUG: kernel NULL pointer dereference, address: 0x0000000000000018\n  RIP: aa_file_perm+0xb7/0x3b0 (or +0xbe/0x3b0, +0xc0/0x3e0)\n  Call Trace:\n   apparmor_file_receive+0x42/0x80\n   security_file_receive+0x2e/0x50\n   receive_fd+0x1d/0xf0\n   scm_detach_fds+0xad/0x1c0\n\nThe function dereferences sock-\u003esk-\u003esk_family without checking if either\nsock or sock-\u003esk is NULL first.\n\nAdd NULL checks for both sock and sock-\u003esk before accessing sk_family."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-05-27T12:18:24.300Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
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          "url": "https://git.kernel.org/stable/c/e85bc9101afc4202aa2269967ce9d3ffbecd0994"
        },
        {
          "url": "https://git.kernel.org/stable/c/e2938ad00b21340c0362562dfedd7cfec0554d67"
        }
      ],
      "title": "apparmor: fix NULL pointer dereference in __unix_needs_revalidation",
      "x_generator": {
        "engine": "bippy-1.2.0"
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    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-45966",
    "datePublished": "2026-05-27T12:18:24.300Z",
    "dateReserved": "2026-05-13T15:03:33.089Z",
    "dateUpdated": "2026-05-27T12:18:24.300Z",
    "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.

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GHSA-G4Q8-M3PW-QHVV

CVE-2026-45966 (GCVE-0-2026-45966)

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Nomenclature