Re: [PATCH] mfd: macsmc: Initialize mutex

[Lee Jones <lee@kernel.org>]

On Thu, 25 Sep 2025, Janne Grunau wrote:

> Struct apple_smc's mutex was not initialized before use. Surprisingly
> this only resulted in occasional NULL pointer dereferences in
> apple_smc_read() calls from the probe() functions of sub devices.
> 
> Fixes: e038d985c9823 ("mfd: Add Apple Silicon System Management Controller")

You need to Cc: Stable as well.  Please submit a [RESEND] with that done.

> Signed-off-by: Janne Grunau <j@jannau.net>
> ---
>  drivers/mfd/macsmc.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/mfd/macsmc.c b/drivers/mfd/macsmc.c
> index 870c8b2028a8fc0e905c8934c2636824cbe5d527..3a117cf19145e86b642f40dc165b542b8df69070 100644
> --- a/drivers/mfd/macsmc.c
> +++ b/drivers/mfd/macsmc.c
> @@ -413,6 +413,7 @@ static int apple_smc_probe(struct platform_device *pdev)
>  	if (!smc)
>  		return -ENOMEM;
>  
> +	mutex_init(&smc->mutex);
>  	smc->dev = &pdev->dev;
>  	smc->sram_base = devm_platform_get_and_ioremap_resource(pdev, 1, &smc->sram);
>  	if (IS_ERR(smc->sram_base))
> 
> ---
> base-commit: 8f5ae30d69d7543eee0d70083daf4de8fe15d585
> change-id: 20250925-macsmc-mutex_init-80d7cb2aacfa
> 
> Best regards,
> -- 
> Janne Grunau <j@jannau.net>
> 

-- 
Lee Jones [李琼斯]