Commit 47a8b0cc (Enable PCIe AER only after checking firmware support) wants to walk the PCI bus in the remove path to disable AER, and calls pci_walk_bus for downstream bridges. Unfortunately, in the remove path, we remove devices and bridges in a depth-first manner, starting with the furthest downstream bridge and working our way backwards. The furthest downstream bridges will not have a dev->subordinate, and we hit a NULL deref in pci_walk_bus. Check for dev->subordinate first before attempting to walk the PCI hierarchy below us. Cc: Andrew Patterson <andrew.patterson@xxxxxx> Signed-off-by: Alex Chiang <achiang@xxxxxx> --- Willy, this is .29 material, please push to Linus, thanks. --- diff --git a/drivers/pci/pcie/aer/aerdrv_core.c b/drivers/pci/pcie/aer/aerdrv_core.c index aebb5f6..677d680 100644 --- a/drivers/pci/pcie/aer/aerdrv_core.c +++ b/drivers/pci/pcie/aer/aerdrv_core.c @@ -133,6 +133,9 @@ static void set_downstream_devices_error_reporting(struct pci_dev *dev, bool enable) { set_device_error_reporting(dev, &enable); + + if (!dev->subordinate) + return; pci_walk_bus(dev->subordinate, set_device_error_reporting, &enable); } -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html