CVE-2026-68356watchdog: airoha: Prevent division by zero when clock frequency is zero

Official description

In the Linux kernel, the following vulnerability has been resolved: watchdog: airoha: Prevent division by zero when clock frequency is zero clk_get_rate() can return 0 when the clock provider is not properly configured or the clock is unmanaged. The driver uses wdt_freq as a divisor directly in airoha_wdt_probe() to compute max_timeout and in airoha_wdt_get_timeleft() to compute the remaining time, which results in a division by zero. Add a check for wdt_freq == 0 in probe and return -EINVAL with dev_err_probe() to prevent the division by zero and provide a diagnostic message.

Affected packages & fixed versions

Affected products (as reported)

References

• https://git.kernel.org/stable/c/8681e5addf7171602616e256a09057697dcc75ca
• https://git.kernel.org/stable/c/57c3f5bd5be008cd5b4ff6a45b7cb90f5ca45a37
• https://git.kernel.org/stable/c/bcfcd7619f277842430d197556463b401b839ee9