lkml.org 
[lkml]   [2015]   [Jan]   [23]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH v2] pci: Fix infinite loop with ROM image of size 0
On Mon, Jan 19, 2015 at 05:53:20PM +0900, Michel Dänzer wrote:
> From: Michel Dänzer <michel.daenzer@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@gmail.com>
> Cc: stable@vger.kernel.org
> Signed-off-by: Michel Dänzer <michel.daenzer@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
>


\
 
 \ /
  Last update: 2015-01-24 01:01    [W:0.058 / U:1.672 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site