{"id":"CVE-2026-98286","title":"In the Linux kernel, the following vulnerability has been resolved:\n\ndrop_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…","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\ndrop_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…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= 9398e9c0b1d44eeb700e9e766c02bcc765c82570 < 9616b0c67fbd8cc0b49de7b26cdf2ab33747c80e","Linux >= 9398e9c0b1d44eeb700e9e766c02bcc765c82570 < bda4d9525fb91a2388ee09669421b8d505290864","Linux >= 9398e9c0b1d44eeb700e9e766c02bcc765c82570 < c391a40f71886b28c082b47270f0e856fa3e1150","Linux 2514c7ad115e762562c7bdd58bb1ab3425a98245","Linux 439b1164da3612ec7e186e1dc314471e7190bfc7","Linux >= 5.10.27 < 5.11","Linux >= 5.11.11 < 5.12","Linux 5.12"],"published":"2026-10-06","updated":"2026-10-06","sourceUpdated":"2026-10-06T09:18:18.740","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-98286","references":[{"url":"https://git.kernel.org/stable/c/9616b0c67fbd8cc0b49de7b26cdf2ab33747c80e","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/bda4d9525fb91a2388ee09669421b8d505290864","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/c391a40f71886b28c082b47270f0e856fa3e1150","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"tags":["nvd","cve.org"],"ingestedAt":"2026-10-06T08:50:17.419Z","slug":"CVE-2026-98286","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\ndrop_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(&data->send_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\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}