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| author | Troy Moure <twmoure@szypr.net> | 2009-06-25 17:05:35 -0600 |
|---|---|---|
| committer | Len Brown <len.brown@intel.com> | 2009-06-26 00:23:42 -0400 |
| commit | 412af97838828bc6d035a1902c8974f944663da6 (patch) | |
| tree | f50b1de9aa3ab2c4ae7db0bf4afeb7f1cc6b2163 /drivers | |
| parent | 3cd530b5aaffd27b231f9717730f2f6684c00bda (diff) | |
| download | lwn-412af97838828bc6d035a1902c8974f944663da6.tar.gz lwn-412af97838828bc6d035a1902c8974f944663da6.zip | |
ACPI: video: prevent NULL deref in acpi_get_pci_dev()
ref: http://thread.gmane.org/gmane.linux.kernel/857228/focus=857468
When the ACPI video driver initializes, it does a namespace walk
looking for for supported devices. When we find an appropriate
handle, we walk up the ACPI tree looking for a PCI root bus, and
then walk back down the PCI bus, assuming that every device
inbetween is a P2P bridge.
This assumption is not correct, and is reported broken on at
least:
Dell Latitude E6400
ThinkPad X61
Dell XPS M1330
Add a NULL deref check to prevent boot panics.
Reported-by: Alessandro Suardi <alessandro.suardi@gmail.com>
Signed-off-by: Troy Moure <twmoure@szypr.net>
Signed-off-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/acpi/pci_root.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c index 8a5bf3b356fa..55b5b90c2a44 100644 --- a/drivers/acpi/pci_root.c +++ b/drivers/acpi/pci_root.c @@ -395,7 +395,7 @@ struct pci_dev *acpi_get_pci_dev(acpi_handle handle) fn = adr & 0xffff; pdev = pci_get_slot(pbus, PCI_DEVFN(dev, fn)); - if (hnd == handle) + if (!pdev || hnd == handle) break; pbus = pdev->subordinate; |