Watchdog Timer Vulnerability in Linux Kernel Affects At91sam9 WDT

CVE-2026-74687

What is CVE-2026-74687?

A vulnerability exists within the Linux kernel's watchdog timer implementation for the at91sam9_wdt device. The issue arises when the at91_ping() function attempts to rearm the watchdog timer during its callback without properly managing the timer's state. This can lead to a scenario where the timer continues to access resources that have already been deallocated, potentially resulting in unexpected behavior or crashes. To mitigate this risk, the solution is to utilize timer_shutdown_sync() to ensure that any running callbacks are completed before the timer is deleted, effectively preventing unauthorized rearming of the timer during critical teardown operations.

References