CVE-2026-98749: Linux kernel · tty: serial: max3100: shut down timer before freeing port
Affects Linux kernelSource CVE Database V5
Not known to be exploited · fixed in fb668620e3b163962dabe1a674725a07aa44ff4a : update Linux kernel when convenient.
Data as of 26 Oct 2026, 14:18 UTC
Rated by Threat Radar · CVSS not yet scored by NVD
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 7% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in fb668620e3b163962dabe1a674725a07aa44ff4a, db0949bbd06db0a75b4b1076f1e25194be7d956a, 247b8f680876313586aed4d267bfcceddc2b4901 +2
Exploitation evidence
Disclosed: evidence found.
CVE published 18 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in– |
Description
In the Linux kernel, the following vulnerability has been resolved: tty: serial: max3100: shut down timer before freeing port max3100_shutdown() stops the polling timer but returns early during system suspend. If the SPI device is unbound before resume, the serial core does not call max3100_shutdown() again, so max3100_remove() frees the port while the timer remains armed. max3100_timeout() may then access the freed port and re-arm the timer. Add final timer teardown to max3100_remove() and use timer_shutdown_sync() to prevent a racing callback from re-arming it. Also free the IRQ and destroy the workqueue there before freeing the port. Keep timer_delete_sync() in max3100_shutdown() so that a subsequent open() can re-arm the timer. The workqueue is created before request_irq() and destroyed on both request_irq() failure and normal shutdown. Its presence at remove thus identifies the IRQ left registered when suspend bypasses shutdown. Free the IRQ before destroying the workqueue, in both max3100_shutdown() and max3100_remove(), and cancel the pending work in between. free_irq() waits for a running interrupt handler to finish and no new handler can start afterwards, so a racing handler cannot queue work on a workqueue that is being destroyed; the force_end_work check in max3100_dowork() only narrows that window, as a handler delayed between the check and queue_work() could still run after the teardown has cleared the workqueue pointer. Cancelling the work also keeps destroy_workqueue() from waiting on a queued work item in case remove() ever runs while the freezable workqueue is still frozen, e.g. device removal during the resume window, before workqueues are thawed. This issue was found by an in-house static analysis tool.
References
- git.kernel.org/stable/c/158a07da2da720f2f98b4bea129212c6805d8ee0 (opens in a new tab)
- git.kernel.org/stable/c/fb668620e3b163962dabe1a674725a07aa44ff4a (opens in a new tab)
- git.kernel.org/stable/c/2c8614981d3e6e000427de0ab2426ab68274d850 (opens in a new tab)
- git.kernel.org/stable/c/247b8f680876313586aed4d267bfcceddc2b4901 (opens in a new tab)
- git.kernel.org/stable/c/db0949bbd06db0a75b4b1076f1e25194be7d956a (opens in a new tab)