kcov: fix data corruption and race conditions on PREEMPT_RT

{
  "id": "79dfd3ebc4384756d41bc05ac3b97ba1fd57c43d0e21dc4a6442ba9a29371727",
  "url": "https://osv.dev/vulnerability/CVE-2026-80916",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "kcov: fix data corruption and race conditions on PREEMPT_RT",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: kcov: fix data corruption and race conditions on PREEMPT_RT syzbot is reporting KCOV state corruption on PREEMPT_RT kernels, for the temporary storage used for saving/restoring remote KCOV state is currently allocated as the per-CPU area. On PREEMPT_RT kernels, softirq handlers run as preemptible task threads (e.g., ksoftirqd). If a softirq context preempts a task running a remote KCOV session, it safely saves the task's state into the per-CPU area. However, if that softirq thread is subsequently preempted by a higher- priority softirq thread on the same CPU, the second softirq will overwrite the same per-CPU area, permanently destroying the original task's KCOV state. Fix this data corruption by moving the temporary storage from the per-CPU area to the per-thread area. Since each softirq thread now owns its own task context, nested softirq preemption no longer causes data overwrites. Note that while the temporary storage is now on a per-thread basis, the per-CPU kcov_percpu_data.lock must be retained, for we need to ensure that kcov_remote_start() and kcov_remote_stop() operate atomically without racing against asynchronous interrupts that manipulate the current task's KCOV state. It is likely that GFP_KERNEL allocation by vmalloc_node() in kcov_init() has already called panic() before returning NULL, for there will be no OOM-killable userspace processes when __init function of built-in module runs. But this",
    "evidence": "osv:CVE-2026-80916",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
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            "value": "5.10.269",
            "evidence": "/affected/1/ranges"
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            "evidence": "/affected/1/ranges"
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          {
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          {
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        "affected_versions": []
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    ],
    "severity": "unknown",
    "structured": {
      "id": "CVE-2026-80916",
      "aliases": [
        "CVE-2026-80916"
      ],
      "affected": [
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              "type": "ECOSYSTEM",
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          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
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      ],
      "modified": "2026-10-28T02:30:49.777714297Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/18799e858b407bf355383c9dd6c06477aa437134",
        "https://git.kernel.org/stable/c/22670d1552fe155822b2abf91f920925f7d067b4",
        "https://git.kernel.org/stable/c/2eed77fdcb0cc48e8eccb2bcd4b7f2c6d650e84c",
        "https://git.kernel.org/stable/c/5dc59fc959b2b5742985d7ef24bccd1868217dc2",
        "https://git.kernel.org/stable/c/8ed3ddf23d39bf5338406bd9f8863d44748cf6ce",
        "https://git.kernel.org/stable/c/a2fb8222cde23b0001812ed3acb7c0ea36dd94e2",
        "https://git.kernel.org/stable/c/e11f5b48c82703242a3be7a7ae4b4940b4cb4610",
        "https://git.kernel.org/stable/c/ef7048d8a614c5f5a9b20513a5428101a744514e",
        "https://git.kernel.org/stable/c/f8c9a3ec36b4ee3d4701b9be08f40e7bfbf89761",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/80xxx/CVE-2026-80916.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-80916",
        "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-2026-80916.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-80916",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-osv",
  "document_id": 518164,
  "published_at": "2026-09-09T16:13:14.587+00:00"
}