Re: [PATCH] driver core: platform: added arguments check for platform_device_add_resources()

[Xujun Leng]

> On Tue, Mar 07, 2023 at 01:01:16PM +0800, Xujun Leng wrote:
> > In the follow two cases, platform_device_add_resources() can lead an
> > invalid address access:
> > 1) If (!res && num > 0), pdev->resource will be set to NULL but
> >    pdev->num_resources > 0, then a later platform_get_resource() will
> >    cause invalid address access.
> > 2) If (res && num == 0), because num == 0 cause kmalloc_slab() returns
> >    ZERO_SIZE_PTR, then kmemdup() will copy data to the invalid address
> >    ZERO_SIZE_PTR.
> > 
> > Signed-off-by: Xujun Leng <lengxujun2007@xxxxxxx>
> > ---
> >  drivers/base/platform.c | 3 +++
> >  1 file changed, 3 insertions(+)
> > 
> > diff --git a/drivers/base/platform.c b/drivers/base/platform.c
> > index 77510e4f47de..a060941c3076 100644
> > --- a/drivers/base/platform.c
> > +++ b/drivers/base/platform.c
> > @@ -606,6 +606,9 @@ int platform_device_add_resources(struct platform_device *pdev,
> >  {
> >  	struct resource *r = NULL;
> >  
> > +	if ((!res && num > 0) || (res && num == 0))
> > +		return -EINVAL;
> 
> What driver is causing this check to fail today?  Shouldn't that be
> fixed instead?

Ok, I got it. It's the caller's responsibility to take care about that.
--
Thanks,

Xujun Leng