MIPS: Work around LLVM bug when gp is used as global register variable

{
  "id": "b635d298a0b14293cec0f6bf7aa5159be8e255cef89ae64e8b0b7c0b4405732e",
  "url": "https://osv.dev/vulnerability/CVE-2026-46250",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "MIPS: Work around LLVM bug when gp is used as global register variable",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: MIPS: Work around LLVM bug when gp is used as global register variable On MIPS, __current_thread_info is defined as global register variable locating in $gp, and is simply assigned with new address during kernel relocation. This however is broken with LLVM, which always restores $gp if it finds $gp is clobbered in any form, including when intentionally through a global register variable. This is against GCC's documentation[1], which requires a callee-saved register used as global register variable not to be restored if it's clobbered. As a result, $gp will continue to point to the unrelocated kernel after the epilog of relocate_kernel(), leading to an early crash in init_idle, [ 0.000000] CPU 0 Unable to handle kernel paging request at virtual address 0000000000000000, epc == ffffffff81afada8, ra == ffffffff81afad90 [ 0.000000] Oops[#1]: [ 0.000000] CPU: 0 UID: 0 PID: 0 Comm: swapper Tainted: G W 6.19.0-rc5-00262-gd3eeb99bbc99-dirty #188 VOLUNTARY [ 0.000000] Tainted: [W]=WARN [ 0.000000] Hardware name: loongson,loongson64v-4core-virtio [ 0.000000] $ 0 : 0000000000000000 0000000000000000 0000000000000001 0000000000000000 [ 0.000000] $ 4 : ffffffff80b80ec0 ffffffff80b53d48 0000000000000000 00000000000f4240 [ 0.000000] $ 8 : 0000000000000100 ffffffff81d82f80 ffffffff81d82f80 0000000000000001 [ 0.000000] $12 : 0000000000000000 ffffffff81776f58 00000000000005da 0000000000000002 [ 0.000000] $16 : ffffffff80b80e40 ",
    "evidence": "osv:CVE-2026-46250",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "5.10.252",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "5.15.202",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.1.165",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.6.128",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.12.75",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.18.14",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.19.4",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-46250",
      "aliases": [
        "CVE-2026-46250"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H"
        }
      ],
      "affected": [
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              "type": "GIT",
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                {
                  "fixed": "05bff9b0ae095b2420cfebb4a96759a09334bec6"
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                {
                  "fixed": "1fe3b402b1e97a1718df3be0a1d3eee20133e735"
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                {
                  "fixed": "4dc65b40fb80c2020efbf139b9a38d30f9a37b92"
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                {
                  "fixed": "c0155dee51b9f5f48aaf5c71cae005eb0e36521f"
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                  "fixed": "e3a6498a63394218561065a9a7a597a204f52f6a"
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                {
                  "fixed": "561834f6d6f52b8a1791331e94b2aac753491d2a"
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                {
                  "fixed": "9bc3b0ae5203aba650297fdf3e1e774125e423f2"
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                {
                  "fixed": "30bfc2d6a1132a89a5f1c3b96c59cf3e4d076ea3"
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              ]
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-46250.json"
          }
        },
        {
          "ranges": [
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              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "4.7.0"
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                {
                  "fixed": "5.10.252"
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          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-46250.json"
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        }
      ],
      "modified": "2026-10-28T02:30:37.092827545Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/05bff9b0ae095b2420cfebb4a96759a09334bec6",
        "https://git.kernel.org/stable/c/1fe3b402b1e97a1718df3be0a1d3eee20133e735",
        "https://git.kernel.org/stable/c/30bfc2d6a1132a89a5f1c3b96c59cf3e4d076ea3",
        "https://git.kernel.org/stable/c/4dc65b40fb80c2020efbf139b9a38d30f9a37b92",
        "https://git.kernel.org/stable/c/561834f6d6f52b8a1791331e94b2aac753491d2a",
        "https://git.kernel.org/stable/c/9bc3b0ae5203aba650297fdf3e1e774125e423f2",
        "https://git.kernel.org/stable/c/c0155dee51b9f5f48aaf5c71cae005eb0e36521f",
        "https://git.kernel.org/stable/c/e3a6498a63394218561065a9a7a597a204f52f6a",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/46xxx/CVE-2026-46250.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-46250",
        "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/2026/46xxx/CVE-2026-46250.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-46250",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 504071,
  "published_at": "2026-06-03T15:49:46.39+00:00"
}