bpf, cgroup: Fix storage null-ptr-deref after replacing prog

{
  "id": "4abbbc0e88c34cb6d5b41b602431befe18f0a8d510761014fac5b9dea81e2c91",
  "url": "https://osv.dev/vulnerability/CVE-2026-90250",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "bpf, cgroup: Fix storage null-ptr-deref after replacing prog",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: bpf, cgroup: Fix storage null-ptr-deref after replacing prog Syzkaller reported a storage null-ptr-deref issue after replacing prog. This occurs in the following scenario: 1. prog A, an empty prog, is attached to a cgrp. 2. prog B uses BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE and calls the bpf_get_local_storage helper. 3. link_update is called to replace prog A with prog B. The reason is that __cgroup_bpf_replace fails to alloc and assign the required cgrp storage for the incoming replacement prog. Consequently, the new prog inherits an uninit storage, leading to null-ptr-deref panic when kick the new prog. Fix this by rejecting a link update if new_prog's cgroup storage is incompatible with link->prog.",
    "evidence": "osv:CVE-2026-90250",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "6.1.191",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.6.160",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.12.110",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.18.52",
            "evidence": "/affected/1/ranges"
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          {
            "value": "7.2.6",
            "evidence": "/affected/1/ranges"
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        "affected_versions": []
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    "severity": "unknown",
    "structured": {
      "id": "CVE-2026-90250",
      "aliases": [
        "CVE-2026-90250"
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      "affected": [
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          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
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          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-90250.json"
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      ],
      "modified": "2026-11-01T02:30:41.977607590Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/12feca126831556dc7fabe5a3ba28fbd328768b6",
        "https://git.kernel.org/stable/c/16c8321ee40c420f8e02e09515a5126682ddf4ea",
        "https://git.kernel.org/stable/c/1ab3da12061d7ccb099f7e925fa2d865967a316a",
        "https://git.kernel.org/stable/c/3f562c537e9ecf4bc5e206cfffc2cc047f1b7e94",
        "https://git.kernel.org/stable/c/85785e7e2ebddcaa5c3b31bd3bcd83ae648985d4",
        "https://git.kernel.org/stable/c/a033c950f6731be88a7da98604ed78f302f15b80",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/90xxx/CVE-2026-90250.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-90250",
        "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
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      "provider_metadata": {
        "cna_assigner": "Linux",
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    "related_cves": [
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        "value": "CVE-2026-90250",
        "evidence": "/id"
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    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-osv",
  "document_id": 499685,
  "published_at": "2026-09-17T16:07:51.403+00:00"
}