Re: [PATCH 1/2] PCI/sysfs: Fix out-of-bounds read in pci_write_legacy_io()

["Krzysztof Wilczyński" <kwilczynski@kernel.org>]

Hello,

> [Severity: High]
> This is a pre-existing issue, but the claim that no changes are needed for
> Alpha doesn't seem quite right.
> 
> Looking at pci_legacy_write() in arch/alpha/kernel/pci-sysfs.c, it calls the
> I/O port functions with the port and value reversed:
> 
> arch/alpha/kernel/pci-sysfs.c:pci_legacy_write() {
>     ...
> 	switch(size) {
> 	case 1:
> 		outb(port, val);
> 		return 1;
> 	case 2:
> 		if (port & 1)
> 			return -EINVAL;
> 		outw(port, val);
> 		return 2;
> 	case 4:
> 		if (port & 3)
> 			return -EINVAL;
> 		outl(port, val);
> 		return 4;
> 	}
>     ...
> }
> 
> Since Alpha's outb(), outw(), and outl() expect arguments in the order
> (value, port), doesn't passing port as the value and val as the port
> address incorrectly use user-supplied data as the target I/O port address?

A known issue for which a fix has been sent:

  https://lore.kernel.org/linux-pci/20260612232400.585195-1-kwilczynski@kernel.org/

Thank you!

	Krzysztof