From: Michel Dänzer <michel.daenzer@xxxxxxx>
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@xxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Michel Dänzer <michel.daenzer@xxxxxxx>
---
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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