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| author | Michel Dänzer <michel.daenzer@amd.com> | 2015-01-19 17:53:20 +0900 |
|---|---|---|
| committer | Bjorn Helgaas <bhelgaas@google.com> | 2015-01-23 17:42:59 -0600 |
| commit | 16b036af31e1456cb69243a5a0c9ef801ecd1f17 (patch) | |
| tree | 843e54f9032b465a487485e6a4a1471e8409c03c /drivers/pci/rom.c | |
| parent | 97bf6af1f928216fd6c5a66e8a57bfa95a659672 (diff) | |
| download | linux-16b036af31e1456cb69243a5a0c9ef801ecd1f17.tar.gz | |
PCI: Fix infinite loop with ROM image of size 0
If the image size would ever read as 0, pci_get_rom_size() could keep processing the same image over and over again. Exit the loop if we ever read a length of zero. This fixes a soft lockup on boot when the radeon driver calls pci_get_rom_size() on an AMD Radeon R7 250X PCIe discrete graphics card. [bhelgaas: changelog, reference] Link: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1386973 Reported-by: Federico <federicotg@gmail.com> Signed-off-by: Michel Dänzer <michel.daenzer@amd.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Alex Deucher <alexander.deucher@amd.com> CC: stable@vger.kernel.org
Diffstat (limited to 'drivers/pci/rom.c')
| -rw-r--r-- | drivers/pci/rom.c | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/drivers/pci/rom.c b/drivers/pci/rom.c index f955edb9bea7..eb0ad530dc43 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 */ |