CVE-2024-38630: watchdog: cpu5wdt.c: Fix use-after-free bug caused by cpu5wdt_trigger

Severity: high (CVSS 7.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-06-21 · updated 2026-10-30
Weakness: CWE-416

Description

In the Linux kernel, the following vulnerability has been resolved: watchdog: cpu5wdt.c: Fix use-after-free bug caused by cpu5wdt_trigger When the cpu5wdt module is removing, the origin code uses del_timer() to de-activate the timer. If the timer handler is running, del_timer() could not stop it and will return directly. If the port region is released by release_region() and then the timer handler cpu5wdt_trigger() calls outb() to write into the region that is released, the use-after-free bug will happen. Change del_timer() to timer_shutdown_sync() in order that the timer handler could be finished before the port region is released.

Affected products

Linux kernel: from 3.8 before 6.6.33; from 6.7 before 6.9.4 — fixed in 6.6.33, 6.9.4
Linux: 2.6.12 — fixed in 6.10

How to fix

Upgrade to a fixed version: Linux kernel 6.6.33, 6.9.4; Linux 6.10. Check the vendor advisory for mitigations.

References

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