)]}'
{
  "commit": "c391a40f71886b28c082b47270f0e856fa3e1150",
  "tree": "dfd445c49c587198606e64c1b321cb18f1ab3ec1",
  "parents": [
    "6a038ef2b57922b6d9ca98ddac0df0681849b704"
  ],
  "author": {
    "name": "Eric Dumazet",
    "email": "edumazet@google.com",
    "time": "Thu Sep 10 20:46:10 2026 +0000"
  },
  "committer": {
    "name": "Jakub Kicinski",
    "email": "kuba@kernel.org",
    "time": "Tue Sep 15 17:58:34 2026 -0700"
  },
  "message": "drop_monitor: use timer_shutdown_sync() to prevent timer rearming during teardown\n\nIn drop_monitor teardown paths (net_dm_trace_off_set(),\nnet_dm_hw_monitor_stop(), and error unwind paths in net_dm_trace_on_set()\nand net_dm_hw_monitor_start()), per-CPU timers are stopped using\ntimer_delete_sync() followed by cancel_work_sync().\n\nHowever, there is a circular dependency between send_timer and\ndm_alert_work:\n1) sched_send_work() (timer callback) schedules dm_alert_work.\n2) send_dm_alert() / net_dm_hw_summary_work() calls reset_per_cpu_data()\n   or net_dm_hw_reset_per_cpu_data().\n3) If memory allocation fails under memory pressure in the reset\n   function, it re-arms the timer via mod_timer(\u0026data-\u003esend_timer, ...).\n\nIf dm_alert_work is running concurrently while timer_delete_sync()\nexecutes on another CPU, an allocation failure in the worker will\nre-arm the timer after timer_delete_sync() has already returned.\nOnce cancel_work_sync() completes and module_put() is called, the timer\nremains active in the timer wheel. If the module is then unloaded, the\ntimer will fire and execute sched_send_work() in freed memory,\ntriggering a kernel panic / use-after-free.\n\nSwitch from timer_delete_sync() to timer_shutdown_sync(). This guarantees\nthat any in-flight timer handler has finished and prevents subsequent\nre-arming attempts from running workers from succeeding. When monitoring\nis restarted later, timer_setup() is invoked, which cleanly\nre-initializes the timer.\n\nFixes: 9398e9c0b1d4 (\"drop_monitor: Perform cleanup upon probe registration failure\")\nSigned-off-by: Eric Dumazet \u003cedumazet@google.com\u003e\nLink: https://patch.msgid.link/20260910204612.3762015-3-edumazet@google.com\nSigned-off-by: Jakub Kicinski \u003ckuba@kernel.org\u003e\n",
  "tree_diff": [
    {
      "type": "modify",
      "old_id": "018d19e3a71de0be50bcc5753ba65f715f678aaa",
      "old_mode": 33188,
      "old_path": "net/core/drop_monitor.c",
      "new_id": "873155ca72432924322bb7961996dd3430d052bc",
      "new_mode": 33188,
      "new_path": "net/core/drop_monitor.c"
    }
  ]
}