From: Wayen Yan Date: Wed, 8 Jul 2026 02:41:54 +0000 (+0800) Subject: watchdog: airoha: Prevent division by zero when clock frequency is zero X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=bcfcd7619f277842430d197556463b401b839ee9;p=thirdparty%2Fkernel%2Flinux.git 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. Fixes: 3cf67f3769b8 ("watchdog: Add support for Airoha EN7851 watchdog") Signed-off-by: Wayen Yan Link: https://lore.kernel.org/r/178347932594.81327.4834644880399144119@gmail.com Signed-off-by: Guenter Roeck --- diff --git a/drivers/watchdog/airoha_wdt.c b/drivers/watchdog/airoha_wdt.c index dc8ca11c14d8..4bd333189b87 100644 --- a/drivers/watchdog/airoha_wdt.c +++ b/drivers/watchdog/airoha_wdt.c @@ -147,6 +147,9 @@ static int airoha_wdt_probe(struct platform_device *pdev) /* Watchdog ticks at half the bus rate */ airoha_wdt->wdt_freq = clk_get_rate(bus_clk) / 2; + if (!airoha_wdt->wdt_freq) + return dev_err_probe(dev, -EINVAL, + "invalid clock frequency\n"); /* Initialize struct watchdog device */ wdog_dev = &airoha_wdt->wdog_dev;