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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2016-03-25 03:53:42 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2016-03-25 03:53:42 -0300
commit03dd4cb26d967f9588437b0fc9cc0e8353322bb7 (patch)
treefa581f6dc1c0596391690d1f67eceef3af8246dc /drivers/pci/rom.c
parentd4e493caf788ef44982e131ff9c786546904d934 (diff)
Linux-libre 4.5-gnu
Diffstat (limited to 'drivers/pci/rom.c')
-rw-r--r--drivers/pci/rom.c23
1 files changed, 11 insertions, 12 deletions
diff --git a/drivers/pci/rom.c b/drivers/pci/rom.c
index eb0ad530d..9eaca39ef 100644
--- a/drivers/pci/rom.c
+++ b/drivers/pci/rom.c
@@ -77,25 +77,24 @@ size_t pci_get_rom_size(struct pci_dev *pdev, void __iomem *rom, size_t size)
do {
void __iomem *pds;
/* Standard PCI ROMs start out with these bytes 55 AA */
- if (readb(image) != 0x55) {
- dev_err(&pdev->dev, "Invalid ROM contents\n");
+ if (readw(image) != 0xAA55) {
+ dev_err(&pdev->dev, "Invalid PCI ROM header signature: expecting 0xaa55, got %#06x\n",
+ readw(image));
break;
}
- if (readb(image + 1) != 0xAA)
- break;
- /* get the PCI data structure and check its signature */
+ /* get the PCI data structure and check its "PCIR" signature */
pds = image + readw(image + 24);
- if (readb(pds) != 'P')
- break;
- if (readb(pds + 1) != 'C')
- break;
- if (readb(pds + 2) != 'I')
- break;
- if (readb(pds + 3) != 'R')
+ if (readl(pds) != 0x52494350) {
+ dev_err(&pdev->dev, "Invalid PCI ROM data signature: expecting 0x52494350, got %#010x\n",
+ readl(pds));
break;
+ }
last_image = readb(pds + 21) & 0x80;
length = readw(pds + 16);
image += length * 512;
+ /* Avoid iterating through memory outside the resource window */
+ if (image > rom + size)
+ break;
} while (length && !last_image);
/* never return a size larger than the PCI resource window */