diff options
| author | Michel Dänzer <michel.daenzer@amd.com> | 2015-01-19 11:53:20 +0300 |
|---|---|---|
| committer | Luis Henriques <luis.henriques@canonical.com> | 2015-02-24 13:01:09 +0300 |
| commit | 9b17c1c81413538901249a27bf39ed39ab40618e (patch) | |
| tree | 97377131399495413c429e21391688bc6bbccf1d /drivers/pci | |
| parent | 2fe5afe766c7c871681432f60b913f72cb64a277 (diff) | |
| download | linux-9b17c1c81413538901249a27bf39ed39ab40618e.tar.xz | |
PCI: Fix infinite loop with ROM image of size 0
commit 16b036af31e1456cb69243a5a0c9ef801ecd1f17 upstream.
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>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
Diffstat (limited to 'drivers/pci')
| -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 */ |