Re: [PATCH v4] PCI: Check rom header and data structure addr before accessing

[Guixin Liu]

在 2025/11/27 01:42, Andy Shevchenko 写道:
> On Wed, Nov 26, 2025 at 07:39:18PM +0200, Andy Shevchenko wrote:
> > On Wed, Nov 26, 2025 at 08:57:27PM +0800, Guixin Liu wrote:
> ...
>
> > >   	image = rom;
> > >   	do {
> > >   		void __iomem *pds;
> > > +
> > > +		if (!pci_rom_header_valid(pdev, image, rom, size, true))
> > >   			break;
> > > +
> > >   		/* get the PCI data structure and check its "PCIR" signature */
> > >   		pds = image + readw(image + 24);
> > > +		if (!pci_rom_data_struct_valid(pdev, pds, rom, size))
> > >   			break;
> > > +
> > > +		last_image = !!(readb(pds + 21) & 0x80);
> > !!() is not needed.
> >
> > 		last_image = readb(pds + 21) & 0x80;
> And while at it, isn't this a bit field and
>
> 		last_image = readb(pds + 21) & BIT(7);
>
> is even more descriptive? Please, check with specification and if it's
> a (single) bit, also change this.
Sure, changed in v5.

Best Regards

Guixin Liu
> > >   		length = readw(pds + 16);
> > >   		image += length * 512;
> > > +
> > > +		if (!pci_rom_header_valid(pdev, image, rom, size, last_image))
> > >   			break;
> > >   	} while (length && !last_image);