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

Vulnerability from cvelistv5 – Published: 2026-05-27 12:18 – Updated: 2026-05-27 12:18
VLAI
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
References
Impacted products
Vendor Product Version
Linux Linux Affected: 88fec3526e84123997ecebd6bb6778eb4ce779b7 , < fea017a7f6abe179decf575a2d8464c74edb3964 (git)
Affected: 88fec3526e84123997ecebd6bb6778eb4ce779b7 , < e85bc9101afc4202aa2269967ce9d3ffbecd0994 (git)
Affected: 88fec3526e84123997ecebd6bb6778eb4ce779b7 , < e2938ad00b21340c0362562dfedd7cfec0554d67 (git)
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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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{
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      "affected": [
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          "product": "Linux",
          "programFiles": [
            "security/apparmor/file.c"
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          "vendor": "Linux",
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              "version": "6.19.4",
              "versionType": "semver"
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              "version": "7.0",
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      "descriptions": [
        {
          "lang": "en",
          "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"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/fea017a7f6abe179decf575a2d8464c74edb3964"
        },
        {
          "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",
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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"
  },
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  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-45966",
      "date": "2026-06-07",
      "epss": "0.00022",
      "percentile": "0.0642"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-45966\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2026-05-27T14:17:13.460\",\"lastModified\":\"2026-05-27T14:48:03.013\",\"vulnStatus\":\"Awaiting Analysis\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"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.\"}],\"metrics\":{},\"references\":[{\"url\":\"https://git.kernel.org/stable/c/e2938ad00b21340c0362562dfedd7cfec0554d67\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/e85bc9101afc4202aa2269967ce9d3ffbecd0994\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/fea017a7f6abe179decf575a2d8464c74edb3964\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}"
  }
}


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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.

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  • 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.
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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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