{"cve":"CVE-2026-98286","nvd":{"published":"2026-10-06T09:18:18.740","modified":"2026-10-19T10:18:30.170","status":"Received","description":"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 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.","cvss_v4":null,"cvss_v3":null,"cwes":[],"references":["https://git.kernel.org/stable/c/9616b0c67fbd8cc0b49de7b26cdf2ab33747c80e","https://git.kernel.org/stable/c/bda4d9525fb91a2388ee09669421b8d505290864","https://git.kernel.org/stable/c/c391a40f71886b28c082b47270f0e856fa3e1150"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:57:46.668721662+00:00"},"epss":{"cve":"CVE-2026-98286","score":0.00166,"percentile":0.0577,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}