Re: [PATCH 25/38] rtc: m48t35: support the SGI IP35 timekeeper's 1968 year base

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [High] rtc: m48t35: null pointer dereference in m48t35_probe() via driver_override
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commit 697b757d9c2a3da93baaf70e4fd5d745beae964e
Author: Imre Kaloz <kaloz@kernel.org>

rtc: m48t35: support the SGI IP35 timekeeper's 1968 year base

This commit updates the M48T35 RTC driver to support the 1968 year base for 
SGI IP35-family machines. It assigns a base epoch using the platform device ID
table and bounds the year to the appropriate century.

> diff --git a/drivers/rtc/rtc-m48t35.c b/drivers/rtc/rtc-m48t35.c
> index 92f19bf997b2f..69c313b4b6e84 100644
> --- a/drivers/rtc/rtc-m48t35.c
> +++ b/drivers/rtc/rtc-m48t35.c

[ ... ]

> @@ -164,6 +154,7 @@ static int m48t35_probe(struct platform_device *pdev)
>  				     pdev->name))
>  		return -EBUSY;
>  
> +	priv->epoch = platform_get_device_id(pdev)->driver_data;

[Severity: High]
Does this code handle devices bound via sysfs driver_override?

If the driver is manually bound to a device using the sysfs driver_override
interface, the platform bus platform_match() function returns success without
calling platform_match_id(). This leaves pdev->id_entry as null.

Since platform_get_device_id(pdev) returns pdev->id_entry, wouldn't
dereferencing its result directly cause a null pointer dereference regression?

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Sashiko AI review · https://sashiko.dev/#/patchset/cover.1790857966.git.kaloz@kernel.org?part=25