Re: [PATCH] misc: pci_endpoint_test: fixed pci_resource_len return value out of bounds.

["Ilpo Järvinen" <ilpo.jarvinen@linux.intel.com>]

On Tue, 17 Dec 2024, Hans Zhang wrote:

> The return type of the API is inconsistent. Inconsistencies may
> result in out-of-bounds.

I'm not sure how out-of-bounds access would happen. On which line you see 
that possibility?

> If the bar size of the EP device exceeds

BAR size

> 4G, this bar_Size will be equal to 0.

bar_size

> For example, there is an EP device, the bar0 size is 16MB, bar1
> size is 32MB, bar2 size is 8GB. When testing bar2, barno equals
> BAR2. Then run pcitest -b 2, console will output "TEST FAILED".

I think bar0 and bar1 information could simply be dropped since they're 
unrelated. I think this would be enough information:

With 8GB BAR2, running pcitest -b 2 fails with "TEST FAILED".

> Variable declaration of bar_size is int, the range less than or
> equal 2G. The return value of pci_resource_len is resource_size_t.
> 
> Signed-off-by: Hans Zhang <18255117159@163.com>
> ---
>  drivers/misc/pci_endpoint_test.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/misc/pci_endpoint_test.c b/drivers/misc/pci_endpoint_test.c
> index 3aaaf47fa4ee..414c4e55fb0a 100644
> --- a/drivers/misc/pci_endpoint_test.c
> +++ b/drivers/misc/pci_endpoint_test.c
> @@ -280,10 +280,11 @@ static int pci_endpoint_test_bar_memcmp(struct pci_endpoint_test *test,
>  static bool pci_endpoint_test_bar(struct pci_endpoint_test *test,
>  				  enum pci_barno barno)
>  {
> -	int j, bar_size, buf_size, iters, remain;
>  	void *write_buf __free(kfree) = NULL;
>  	void *read_buf __free(kfree) = NULL;
>  	struct pci_dev *pdev = test->pdev;
> +	int j, buf_size, iters, remain;
> +	resource_size_t bar_size;
>  
>  	if (!test->bar[barno])
>  		return false;
> 

The code change itself is good.

-- 
 i.