Re: [PATCH] pinctrl: sunxi: fix use-after-free in sunxi_pmx_free()

[liu xiang]

> Hi,

> On Tue, Jan 19, 2021 at 02:29:08PM +0800, Liu Xiang wrote:
> When CONFIG_REGULATOR is not set, sunxi_pmx_request() always return
> success. Even a group of pins call sunxi_pmx_request(), the refcount
> is only 1. This can cause a use-after-free warning in sunxi_pmx_free().
> To solve this problem, go to err path if regulator_get() return NULL
> or error.
> 
> Signed-off-by: Liu Xiang <liu.xiang@xxxxxxxxxxxxxx>

> Is there any drawback to depending on CONFIG_REGULATOR?

> Given that we need those regulators enabled anyway, I guess we could
> just select or depends on it
>
> Maxime


Yes, I think so. But CONFIG_REGULATOR is not enabled by default now.
So I can find this problem during startup.