Re: [PATCH] driver core: Fix possible use after free on name

Greg KH
2020-04-06T08:29:04Z

A: http://en.wikipedia.org/wiki/Top_post
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http://daringfireball.net/2007/07/on_top

On Mon, Apr 06, 2020 at 03:40:41PM +0800, Fei Zhang wrote:
> Dear Greg,
>
> Mostly, "class_creat" is used in kernel driver module, basically
> read-only strings,
> but it is easier to use a local variable string. When writing drive module,
> it fails to judge the local variable string which cannot be passed in
> only via interface.
> I found that someone else may also face the same problem.

An individual driver should NOT be creating a class, that is not what it
is there for.

Class names are very "rare" and should not be dynamically created at
all.

> If we have 2 identical hardwares with different internal logic(fpga),
> it may be more
> appropriate to create dynamic classes according to the logical functions.

No it is not appropriate at all to do that.

So, I'll ignore this patch as this is not something that you all should
do. If an in-kernel user needs this, I will be glad to revisit this
issue, so I strongly suggest you work to get your code merged upstream
properly, so we can review it and suggest what you should be doing
instead.

thanks,

greg k-h