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Date:   Sun, 4 Sep 2022 08:20:55 +0200
From:   Greg KH <gregkh@linuxfoundation.org>
To:     Li Zhong <floridsleeves@gmail.com>
Cc:     linux-kernel@vger.kernel.org, rafael@kernel.org
Subject: Re: [PATCH v2] drivers/base/auxiliary: check return value of
 strrchr()
Message-ID: <YxRDx7DEIXEDGXRj@kroah.com>
References: <20220904005156.2281982-1-floridsleeves@gmail.com>
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On Sat, Sep 03, 2022 at 05:51:56PM -0700, Li Zhong wrote:
> The return value of strrchr() could be NULL, which will cause invalid
> offset in (int)(p - name). So we check it here.
> 
> Signed-off-by: Li Zhong <floridsleeves@gmail.com>
> ---
>  drivers/base/auxiliary.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/base/auxiliary.c b/drivers/base/auxiliary.c
> index 8c5e65930617..2ec0306bfba3 100644
> --- a/drivers/base/auxiliary.c
> +++ b/drivers/base/auxiliary.c
> @@ -191,6 +191,8 @@ static int auxiliary_uevent(struct device *dev, struct kobj_uevent_env *env)
>  
>  	name = dev_name(dev);
>  	p = strrchr(name, '.');
> +	if (!p)
> +		return -EINVAL;

How can that ever happen?  For what device will that be triggered?

And again, please follow Documentation/process/researcher-guidelines.rst