mm/page_alloc: don't spin_trylock() in NMI on UP

{
  "id": "023fb3cecd52e47c4ccd49e0e5ebbdc27dc57161dec163d605cc04e4eb62087b",
  "url": "https://osv.dev/vulnerability/CVE-2026-90046",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "mm/page_alloc: don't spin_trylock() in NMI on UP",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: mm/page_alloc: don't spin_trylock() in NMI on UP Patch series \"mm/page_alloc: fixes for free_pages_nolock() on RT/UP\". Pre-existing bugs found by Sashiko during review of this other series: https://lore.kernel.org/all/20260703-alloc-trylock-v5-0-c87b714e19d3@google.com/ I have not reproduced these bugs, and I suspect there is no real-world user that is affected by them. This patch (of 2): As noted in can_spin_trylock(), using this is unsafe in this context. commit 620b46ed6ae17 (\"mm/page_alloc: return NULL early from alloc_frozen_pages_nolock() in NMI on UP\") fixed this on the alloc side but missed the free side. Impact: If BPF programs using these features in NMI (probably tracing) are present on non-SMP builds this might crash the kernel and is probably exploitable by local attackers for privilege escalation.",
    "evidence": "osv:CVE-2026-90046",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "6.18.51",
            "evidence": "/affected/1/ranges"
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            "value": "7.2.5",
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    "structured": {
      "id": "CVE-2026-90046",
      "aliases": [
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              "type": "ECOSYSTEM",
              "events": [
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                  "introduced": "6.15.0"
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                {
                  "fixed": "6.18.51"
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              "type": "ECOSYSTEM",
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                  "introduced": "6.19.0"
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            "ecosystem": "Linux"
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      "modified": "2026-10-28T02:30:41.115139399Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/06c76d3c389ff504052f64b1acee44651bd847fa",
        "https://git.kernel.org/stable/c/3105ae628fb785d48b49256468be4f21a7b3cfc0",
        "https://git.kernel.org/stable/c/68a069b407303e71db371df85036101e8ff59280",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/90xxx/CVE-2026-90046.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-90046",
        "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
      ],
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        "cna_assigner": "Linux",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/90xxx/CVE-2026-90046.json"
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  "source_id": "core-osv",
  "document_id": 509085,
  "published_at": "2026-09-16T10:33:43.156+00:00"
}