{
  "cveId": "CVE-2025-40327",
  "url": "https://patchblox.com/security/cve/CVE-2025-40327",
  "summary": "CVE-2025-40327 is fixed in linux on 1 platform by DEBIAN-CVE-2025-40327 (version 6.17.8-1), released December 9, 2025. It is not reported as exploited. Patch Radar priority: Routine.",
  "title": "linux: In the Linux kernel, the following vulnerability has been resolved:  perf/core: Fix system hang caused by cpu-clock u...",
  "description": "In the Linux kernel, the following vulnerability has been resolved:  perf/core: Fix system hang caused by cpu-clock usage  cpu-clock usage by the async-profiler tool can trigger a system hang, which got bisected back to the following commit by Octavia Togami:    18dbcbfabfff (\u0022perf: Fix the POLL_HUP delivery breakage\u0022) causes this issue  The root cause of the hang is that cpu-clock is a special type of SW event which relies on hrtimers. The __perf_event_overflow() callback is invoked from the hrtimer handler for cpu-clock events, and __perf_event_overflow() tries to call cpu_clock_event_stop() to stop the event, which calls htimer_cancel() to cancel the hrtimer.  But that\u0027s a recursion into the hrtimer code from a hrtimer handler, which (unsurprisingly) deadlocks.  To fix this bug, use hrtimer_try_to_cancel() instead, and set the PERF_HES_STOPPED flag, which causes perf_swevent_hrtimer() to stop the event once it sees the PERF_HES_STOPPED flag.  [ mingo: Fixed the comments and improved the changelog. ]",
  "published": "2025-12-09T16:17:42Z",
  "severity": "",
  "epss": 0.0021,
  "epssPercentile": 0.11224,
  "priority": "Routine",
  "priorityTier": 4,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "fixes": [
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 14",
      "fixedVersion": "6.17.8-1",
      "fix": "DEBIAN-CVE-2025-40327",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2025-40327",
      "released": "2025-12-09T16:17:42Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-08T06:59:42Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}