{
  "schemaVersion": 1,
  "attribution": [
    {
      "source": "CISA Known Exploited Vulnerabilities",
      "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog",
      "licence": "US government work"
    },
    {
      "source": "GitHub Advisory Database",
      "url": "https://github.com/advisories",
      "licence": "CC BY 4.0"
    },
    {
      "source": "Have I Been Pwned",
      "url": "https://haveibeenpwned.com/",
      "licence": "CC BY 4.0"
    },
    {
      "source": "CVE Program (CVE records)",
      "url": "https://www.cve.org/Legal/TermsOfUse",
      "licence": "CVE Terms of Use",
      "notice": "Copyright © 1999-2026, The MITRE Corporation. CVE is a trademark and the CVE logo is a registered trademark of The MITRE Corporation.",
      "terms": "CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE™). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy."
    },
    {
      "source": "FIRST EPSS",
      "url": "https://www.first.org/epss/",
      "licence": "free to use; FIRST requests attribution"
    }
  ],
  "record": {
    "id": "CVE-2026-23342",
    "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2026-23342",
    "idYear": 2026,
    "status": "PUBLISHED",
    "publishedAt": "2026-03-25T10:27:30.285Z",
    "updatedAt": "2026-05-11T22:04:59.186Z",
    "importedAt": "2026-10-24T01:58:02.025Z",
    "snapshot": {
      "id": "cve_2026-10-24_midnight_baseline",
      "at": "2026-10-24T00:00:00.000Z",
      "source": "https://github.com/CVEProject/cvelistV5/releases/tag/cve_2026-10-24_0100Z"
    },
    "facts": {
      "title": "bpf: Fix race in cpumap on PREEMPT_RT",
      "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Fix race in cpumap on PREEMPT_RT\n\nOn PREEMPT_RT kernels, the per-CPU xdp_bulk_queue (bq) can be accessed\nconcurrently by multiple preemptible tasks on the same CPU.\n\nThe original code assumes bq_enqueue() and __cpu_map_flush() run\natomically with respect to each other on the same CPU, relying on\nlocal_bh_disable() to prevent preemption. However, on PREEMPT_RT,\nlocal_bh_disable() only calls migrate_disable() (when\nPREEMPT_RT_NEEDS_BH_LOCK is not set) and does not disable\npreemption, which allows CFS scheduling to preempt a task during\nbq_flush_to_queue(), enabling another task on the same CPU to enter\nbq_enqueue() and operate on the same per-CPU bq concurrently.\n\nThis leads to several races:\n\n1. Double __list_del_clearprev(): after bq->count is reset in\n   bq_flush_to_queue(), a preempting task can call bq_enqueue() ->\n   bq_flush_to_queue() on the same bq when bq->count reaches\n   CPU_MAP_BULK_SIZE. Both tasks then call __list_del_clearprev()\n   on the same bq->flush_node, the second call dereferences the\n   prev pointer that was already set to NULL by the first.\n\n2. bq->count and bq->q[] races: concurrent bq_enqueue() can corrupt\n   the packet queue while bq_flush_to_queue() is processing it.\n\nThe race between task A (__cpu_map_flush -> bq_flush_to_queue) and\ntask B (bq_enqueue -> bq_flush_to_queue) on the same CPU:\n\n  Task A (xdp_do_flush)          Task B (cpu_map_enqueue)\n  ----------------------         ------------------------\n  bq_flush_to_queue(bq)\n    spin_lock(&q->producer_lock)\n    /* flush bq->q[] to ptr_ring */\n    bq->count = 0\n    spin_unlock(&q->producer_lock)\n                                   bq_enqueue(rcpu, xdpf)\n    <-- CFS preempts Task A -->      bq->q[bq->count++] = xdpf\n                                     /* ... more enqueues until full ... */\n                                     bq_flush_to_queue(bq)\n                                       spin_lock(&q->producer_lock)\n                                       /* flush to ptr_ring */\n                                       spin_unlock(&q->producer_lock)\n                                       __list_del_clearprev(flush_node)\n                                         /* sets flush_node.prev = NULL */\n    <-- Task A resumes -->\n    __list_del_clearprev(flush_node)\n      flush_node.prev->next = ...\n      /* prev is NULL -> kernel oops */\n\nFix this by adding a local_lock_t to xdp_bulk_queue and acquiring it\nin bq_enqueue() and __cpu_map_flush(). These paths already run under\nlocal_bh_disable(), so use local_lock_nested_bh() which on non-RT is\na pure annotation with no overhead, and on PREEMPT_RT provides a\nper-CPU sleeping lock that serializes access to the bq.\n\nTo reproduce, insert an mdelay(100) between bq->count = 0 and\n__list_del_clearprev() in bq_flush_to_queue(), then run reproducer\nprovided by syzkaller.",
      "affected": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "versions": [
            {
              "version": "3253cb49cbad4772389d6ef55be75db1f97da910",
              "status": "affected",
              "versionType": "git",
              "lessThan": "7466ae2aeed483de80c5d8dea0913cf74038b652"
            },
            {
              "version": "3253cb49cbad4772389d6ef55be75db1f97da910",
              "status": "affected",
              "versionType": "git",
              "lessThan": "e67299e1044349ad0088d52c6bc5764cc1816c06"
            },
            {
              "version": "3253cb49cbad4772389d6ef55be75db1f97da910",
              "status": "affected",
              "versionType": "git",
              "lessThan": "869c63d5975d55e97f6b168e885452b3da20ea47"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "versions": [
            {
              "version": "6.18",
              "status": "affected"
            },
            {
              "version": "0",
              "status": "unaffected",
              "versionType": "semver",
              "lessThan": "6.18"
            },
            {
              "version": "6.18.17",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.18.*"
            },
            {
              "version": "6.19.7",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.19.*"
            },
            {
              "version": "7.0",
              "status": "unaffected",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ]
        }
      ]
    }
  }
}