Re: [bug report] PCI: Check BAR index for validity

[Bjorn Helgaas <helgaas@kernel.org>]

On Sat, Mar 08, 2025 at 01:23:28PM +0300, Dan Carpenter wrote:
> Hello Philipp Stanner,
> 
> Commit ba10e5011d05 ("PCI: Check BAR index for validity") from Mar 4,
> 2025 (linux-next), leads to the following Smatch static checker
> warning:
> 
> 	drivers/pci/devres.c:632 pcim_remove_bar_from_legacy_table()
> 	error: buffer overflow 'legacy_iomap_table' 6 <= 15

Thanks, I dropped this patch for now.

> drivers/pci/devres.c
>     621 static void pcim_remove_bar_from_legacy_table(struct pci_dev *pdev, int bar)
>     622 {
>     623         void __iomem **legacy_iomap_table;
>     624 
>     625         if (!pci_bar_index_is_valid(bar))
> 
> This line used to check PCI_STD_NUM_BARS (6) but now it's checking
> PCI_NUM_RESOURCES (15).
> 
>     626                 return;
>     627 
>     628         legacy_iomap_table = (void __iomem **)pcim_iomap_table(pdev);
>     629         if (!legacy_iomap_table)
>     630                 return;
>     631 
> --> 632         legacy_iomap_table[bar] = NULL;
>                 ^^^^^^^^^^^^^^^^^^^^^^^
> Leading to a buffer overflow.
> 
>     633 }
> 
> regards,
> dan carpenter