CVE-2026-98286drop_monitor: use timer_shutdown_sync() to prevent timer rearming during teardown
- —Not scoredno CVSS score yet
- 0.17%Exploitation in 30 daysEPSS · top 94% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
In the Linux kernel, the following vulnerability has been resolved: drop_monitor: use timer_shutdown_sync() to prevent timer rearming during teardown In drop_monitor teardown paths (net_dm_trace_off_set(), net_dm_hw_monitor_stop(), and error unwind paths in net_dm_trace_on_set() and net_dm_hw_monitor_start()), per-CPU timers are stopped using timer_delete_sync() followed by cancel_work_sync(). However, there is a circular dependency between send_timer and dm_alert_work: 1) sched_send_work() (timer callback) schedules dm_alert_work. 2) send_dm_alert() / net_dm_hw_summary_work() calls reset_per_cpu_data() or net_dm_hw_reset_per_cpu_data(). 3) If memory allocation fails under memory pressure in the reset function, it re-arms the timer via mod_timer(&data->send_timer, ...). If dm_alert_work is running concurrently while timer_delete_sync() executes on another CPU, an allocation failure in the worker will re-arm the timer after timer_delete_sync() has already returned. Once cancel_work_sync() completes and module_put() is called, the timer remains active in the timer wheel. If the module is then unloaded, the timer will fire and execute sched_send_work() in freed memory, triggering a kernel panic / use-after-free. Switch from timer_delete_sync() to timer_shutdown_sync(). This guarantees that any in-flight timer handler has finished and prevents subsequent re-arming attempts from running workers from succeeding. When monitoring is restarted later, timer_setup() is invoked, which cleanly re-initializes the timer.
Timeline
ID reserved
By Linux
- 11 days later
· 11 days later
Published
- 13 days later
· 13 days later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
No CVSS score yet: neither the CNA, CISA nor NVD has scored this CVE. NVD status: Received.
- EPSS (exploitation in 30 days)
- 0.17% · top 94% of all CVEs (12 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: Not scored.
Affected products
- affected 9398e9c0b1d44eeb700e9e766c02bcc765c82570 – < 9616b0c67fbd8cc0b49de7b26cdf2ab33747c80e
- affected 9398e9c0b1d44eeb700e9e766c02bcc765c82570 – < bda4d9525fb91a2388ee09669421b8d505290864
- affected 9398e9c0b1d44eeb700e9e766c02bcc765c82570 – < c391a40f71886b28c082b47270f0e856fa3e1150
- affected 2514c7ad115e762562c7bdd58bb1ab3425a98245
- affected 439b1164da3612ec7e186e1dc314471e7190bfc7
- affected 5.10.27 – < 5.11
- affected 5.11.11 – < 5.12
- affected 5.12
- unaffected < 5.12
- unaffected 6.18.54 – ≤ 6.18.*
- unaffected 7.2.8 – ≤ 7.2.*
- unaffected 7.3 – ≤ *
References
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-93214 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
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[](https://cveledger.app/cve/CVE-2026-98286)Record last updated .