On Mon, Jan 19, 2015 at 05:53:20PM +0900, Michel Dänzer wrote:
> From: Michel Dänzer <michel.daenzer at amd.com>
> 
> If the image size would ever read as 0, pci_get_rom_size could keep
> processing the same image over and over again.
> 
> Reported-by: Federico <federicotg at gmail.com>
> Cc: stable at vger.kernel.org
> Signed-off-by: Michel Dänzer <michel.daenzer at amd.com>

Applied with Alex's ack to pci/resource for v3.20, thanks!

> ---
> 
> v2:
> * Use unsigned instead of u16 for the local length variable (not sure if
>   the multiplication by 512 could overflow otherwise)
> * Integrate length condition into while statement
> * Add stable tag
> 
>  drivers/pci/rom.c | 7 ++++---
>  1 file changed, 4 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/pci/rom.c b/drivers/pci/rom.c
> index f955edb..eb0ad53 100644
> --- a/drivers/pci/rom.c
> +++ b/drivers/pci/rom.c
> @@ -71,6 +71,7 @@ size_t pci_get_rom_size(struct pci_dev *pdev, void __iomem 
> *rom, size_t size)
>  {
>       void __iomem *image;
>       int last_image;
> +     unsigned length;
>  
>       image = rom;
>       do {
> @@ -93,9 +94,9 @@ size_t pci_get_rom_size(struct pci_dev *pdev, void __iomem 
> *rom, size_t size)
>               if (readb(pds + 3) != 'R')
>                       break;
>               last_image = readb(pds + 21) & 0x80;
> -             /* this length is reliable */
> -             image += readw(pds + 16) * 512;
> -     } while (!last_image);
> +             length = readw(pds + 16);
> +             image += length * 512;
> +     } while (length && !last_image);
>  
>       /* never return a size larger than the PCI resource window */
>       /* there are known ROMs that get the size wrong */
> -- 
> 2.1.4
> 

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