erofs: cap LZMA stream pool size

{
  "id": "157c68df8f31097a1607ca10b143ea3f78da781068814858d4d7901a37a361f9",
  "url": "https://osv.dev/vulnerability/CVE-2026-80892",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "erofs: cap LZMA stream pool size",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: erofs: cap LZMA stream pool size fs/erofs/decompressor_lzma.c sizes the module-global MicroLZMA stream pool from num_possible_cpus() when the lzma_streams module parameter is unset, then z_erofs_load_lzma_config() preallocates one image-supplied dictionary per stream, accepting dictionaries up to 8 MiB. On high-CPU systems, a small EROFS image can pin hundreds of MiB of vmalloc-backed decoder state until the erofs module is unloaded. Impact: An EROFS image mounted by the system can pin up to 8 MiB of vmalloc memory per LZMA stream, either as intended or unexpectedly. Bound the default stream count by a new CONFIG_EROFS_FS_ZIP_LZMA_DEFAULT_MAX_STREAMS option, default 16, so the worst-case default preallocation is 128 MiB if the number of CPUs is no less than 16 while preserving the existing per-image dictionary limit. An explicit lzma_streams module parameter is still honoured as-is, so administrators who deliberately size the pool are not affected.",
    "evidence": "osv:CVE-2026-80892",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "6.1.184",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.6.151",
            "evidence": "/affected/1/ranges"
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          {
            "value": "6.12.103",
            "evidence": "/affected/1/ranges"
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          {
            "value": "6.18.44",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "7.1.8",
            "evidence": "/affected/1/ranges"
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        "affected_versions": []
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    "severity": "unknown",
    "structured": {
      "id": "CVE-2026-80892",
      "aliases": [
        "CVE-2026-80892"
      ],
      "affected": [
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                  "fixed": "5aaa06dfc10f8398c8807453dbec738ea9af10e4"
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                {
                  "fixed": "e52da169b8c0d19bb2d803f2a07fe0e5a00462d6"
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                {
                  "fixed": "c9b47e6b23114e939b17f818471c7a46e59006e7"
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                  "introduced": "6.19.0"
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          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
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        }
      ],
      "modified": "2026-10-28T02:30:45.614567899Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/0c676903cb2a61992ded8e7907609cc6b0f11744",
        "https://git.kernel.org/stable/c/5aaa06dfc10f8398c8807453dbec738ea9af10e4",
        "https://git.kernel.org/stable/c/682cb3ece37fc5141e73bc726ccf4adb833e5189",
        "https://git.kernel.org/stable/c/c9b47e6b23114e939b17f818471c7a46e59006e7",
        "https://git.kernel.org/stable/c/e52da169b8c0d19bb2d803f2a07fe0e5a00462d6",
        "https://git.kernel.org/stable/c/e8b3d09aa8889dda9be9cbb3d2f0218c4b9acde4",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/80xxx/CVE-2026-80892.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-80892",
        "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
      ],
      "provider_metadata": {
        "cna_assigner": "Linux",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/80xxx/CVE-2026-80892.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-80892",
        "evidence": "/id"
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    ],
    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-osv",
  "document_id": 513843,
  "published_at": "2026-09-04T17:11:08.391+00:00"
}