{
  "affected": [
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:12",
        "name": "linux"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:13",
        "name": "linux"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:14",
        "name": "linux"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "details": "In the Linux kernel, the following vulnerability has been resolved:  tracing: Fix hist trigger timestamps for buffered events  Syzkaller triggered a WARN_ON_ONCE(!nest) warning:    WARNING: kernel/trace/ring_buffer.c:821 at ring_buffer_event_time_stamp   Call trace:     ring_buffer_event_time_stamp     hist_field_timestamp     hist_fn_call     event_hist_trigger     event_triggers_call     __event_trigger_test_discard     trace_event_buffer_commit     do_trace_event_raw_event_sched_switch     trace_event_raw_event_sched_switch  The warning is probabilistically reproducible and is related to syzkaller executing the following commands:    echo 'prev_pid == 999999' \u003e events/sched/sched_switch/filter   echo 'hist:keys=common_timestamp' \u003e events/sched/sched_switch/trigger  The specific triggering process is as follows:  CPU 0                                           CPU 1 (context switching)                             (echo 'hist:keys=common_timestamp' \u003e \\                                                         events/sched/sched_switch/trigger) do_trace_event_raw_event_##call   trace_event_buffer_lock_reserve     if (!tr-\u003eno_filter_buffering_ref \u0026\u0026         trace_file-\u003eflags \u0026 EVENT_FILE_FL_FILTERED)         return entry;  // return directly                                                 event_hist_trigger_parse                                                   hist_register_trigger                                                     tracing_set_filter_buffering(file-\u003etr, true);                                                       tr-\u003eno_filter_buffering_ref++;     __trace_buffer_lock_reserve       rb_start_commit         local_inc(\u0026cpu_buffer-\u003ecommitting);  // skipped and not executed   trace_event_buffer_commit     __event_trigger_test_discard       event_triggers_call         event_hist_trigger           hist_fn_call             hist_field_timestamp               ring_buffer_event_time_stamp                 nest = local_read(\u0026cpu_buffer-\u003ecommitting);                 WARN_ON_ONCE(!nest)  // trigger warning  The root cause is that when an event file has a filter attached and the hist trigger has not yet been attached, trace_event_buffer_lock_reserve() writes the event into the per-CPU trace_buffered_event temp buffer instead of reserving it in the ring buffer, so cpu_buffer-\u003ecommitting is not incremented. When the event is later processed at commit time by a hist trigger, hist_field_timestamp() -\u003e ring_buffer_event_time_stamp() sees a zero committing count, triggering WARN_ON_ONCE(!nest).  tracing_event_time_stamp() was added by commit d8279bfc5e959 (\"tracing: Add tracing_event_time_stamp() API\") for exactly this case: if the event is the per-CPU trace_buffered_event, it returns the current ring buffer timestamp. But it never gained a caller. Use it in hist_field_timestamp(), so that a hist trigger that races onto a buffered event records the current time, which is only marginally later than when the event was recorded, instead of warning and recording a bogus timestamp.",
  "id": "DEBIAN-CVE-2026-99140",
  "modified": "2026-10-29T05:47:28.977488157Z",
  "published": "2026-10-28T11:17:33.960Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://security-tracker.debian.org/tracker/CVE-2026-99140"
    }
  ],
  "upstream": [
    "CVE-2026-99140"
  ]
}