Re: [PATCH] clocksource: Remove redundant dev_err()/dev_err_probe()

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:

Pre-existing issues:
- [High] If `devm_request_irq()` fails, the driver exits with an error without unregistering the clockevent device, leaving a dangling pointer in the global clockevents subsystem which leads to a use-after-free.
--

--- Patch [1]: [PATCH] clocksource: Remove redundant dev_err()/dev_err_probe() ---
commit 6abdbb5acc54b54b2834aaea50a1948deb00002c
Author: Pan Chuang <panchuang@vivo.com>

clocksource: Remove redundant dev_err()/dev_err_probe()

This commit removes redundant driver-specific error logging following
devm_request_irq(), since the core function now automatically logs detailed
error messages on failure.

[ ... ]

> diff --git a/drivers/clocksource/timer-sun5i.c b/drivers/clocksource/timer-sun5i.c
> index 6ab300d226215..bcf155fb9cac2 100644
> --- a/drivers/clocksource/timer-sun5i.c
> +++ b/drivers/clocksource/timer-sun5i.c
> @@ -247,10 +247,8 @@ static int sun5i_setup_clockevent(struct platform_device *pdev,
>  	ret = devm_request_irq(dev, irq, sun5i_timer_interrupt,
>  			       IRQF_TIMER | IRQF_IRQPOLL,
>  			       "sun5i_timer0", ce);
> -	if (ret) {
> -		dev_err(dev, "Unable to register interrupt\n");
> +	if (ret)
>  		return ret;

[Severity: High]
This isn't a bug introduced by this patch, but since we are modifying this
error path, does this return leave a dangling pointer in the clockevents
subsystem?

In sun5i_setup_clockevent(), clockevents_config_and_register() is called
just prior to devm_request_irq() to register the clockevent on the global
list. If the IRQ request fails, the function returns immediately without
unregistering the clockevent device.

Since the struct sun5i_timer is managed by devres, it is freed when the
probe fails, potentially leading to a use-after-free when the clockevents
core evaluates or iterates over its global list.

Should this path unregister the clockevent on failure?

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260713130740.293502-1-panchuang@vivo.com?part=1