[PATCH 1/4] PCI: shpchp: bail out if pci_hp_add_bridge() fails

From: Nam Cao
Date: Fri May 03 2024 - 15:23:49 EST


If there is no bus number available for the downstream bus of the
hot-plugged bridge, pci_hp_add_bridge() will fail. The driver proceeds
regardless, and the kernel crashes.

Abort if pci_hp_add_bridge() fails.

Fixes: 7d01f70ac6f4 ("PCI: shpchp: use generic pci_hp_add_bridge()")
Signed-off-by: Nam Cao <namcao@xxxxxxxxxxxxx>
Cc: Yinghai Lu <yinghai@xxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
---
drivers/pci/hotplug/shpchp_pci.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/hotplug/shpchp_pci.c b/drivers/pci/hotplug/shpchp_pci.c
index 36db0c3c4ea6..2ac98bdc83d9 100644
--- a/drivers/pci/hotplug/shpchp_pci.c
+++ b/drivers/pci/hotplug/shpchp_pci.c
@@ -48,8 +48,13 @@ int shpchp_configure_device(struct slot *p_slot)
}

for_each_pci_bridge(dev, parent) {
- if (PCI_SLOT(dev->devfn) == p_slot->device)
- pci_hp_add_bridge(dev);
+ if (PCI_SLOT(dev->devfn) == p_slot->device) {
+ if (pci_hp_add_bridge(dev)) {
+ pci_stop_and_remove_bus_device(dev);
+ ret = -EINVAL;
+ goto out;
+ }
+ }
}

pci_assign_unassigned_bridge_resources(bridge);
--
2.39.2