{
  "cveId": "CVE-2026-99234",
  "url": "https://patchblox.com/security/cve/CVE-2026-99234",
  "summary": "CVE-2026-99234 is fixed in linux on 1 platform, first by DEBIAN-CVE-2026-99234, released November 3, 2026. It is not reported as exploited. Patch Radar priority: Routine.",
  "title": "tracing: Unregister field variable histograms when the command fails",
  "description": "In the Linux kernel, the following vulnerability has been resolved:  tracing: Unregister field variable histograms when the command fails  An action that names a field on another event needs that field as a variable, so create_field_var_hist() registers a second hist trigger on that event to provide it, and records it in target_hist_data-\u003Efield_var_hists[].  If a later part of the same command fails, create_actions() returns an error and event_hist_trigger_parse() jumps to out_free. The write fails with -EINVAL and sched_switch gets no trigger, but:    # echo \u0027hist:keys=pid:ts0=common_timestamp.usecs\u0027 \u003E\u003E \\       events/sched/sched_waking/trigger   # echo \u0027my_synth u64 lat; int a; int b\u0027 \u003E\u003E synthetic_events   # echo \u0027hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0:\\       onmatch(sched.sched_waking).my_synth($wakeup_lat,prio,nosuchfld)\u0027\\       \u003E\u003E events/sched/sched_switch/trigger   # cat events/sched/sched_waking/trigger   hist:keys=pid:vals=hitcount:ts0=common_timestamp.usecs:sort=hitcount:size=2048:clock=global [active]   hist:keys=pid:vals=hitcount:synthetic_prio=prio:sort=hitcount:size=2048 [active]  The second histogram is the one created for \u0027prio\u0027. It is still active and still counting.  out_free reaches destroy_field_var_hists(), which frees the field_var_hists[] entries, but never unregister_field_var_hists(), which is what removes the triggers and runs only from event_hist_trigger_free(). The entry is freed and the trigger is left with nothing tracking it.  Unregister the field variable histograms in out_free as well, and record each one as soon as its trigger is registered rather than after the lookup that follows it, so no exit can leave a registered trigger untracked. The entry then belongs to field_var_hists[] and is released by destroy_field_var_hists(), so freeing it on that exit would be a double free.",
  "published": "2026-11-02T16:17:48Z",
  "severity": "Low",
  "cvss": 3.4,
  "epss": 0.00182,
  "epssPercentile": 0.07855,
  "priority": "Routine",
  "priorityTier": 4,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "vendorAdvisory": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-99234",
  "fixes": [
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 13.5 (trixie)",
      "fixedVersion": "6.12.115-1",
      "fix": "DEBIAN-CVE-2026-99234",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-99234",
      "released": "2026-11-03T18:58:21Z"
    },
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 14",
      "fixedVersion": "7.2.14-1",
      "fix": "DEBIAN-CVE-2026-99234",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-99234",
      "released": "2026-11-03T18:58:21Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-09T01:18:40Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}