When a slot is removed, the pci_dev must still exist.
pci_remove_root_bus() removes and free all the pci_devs, so
hv_pci_remove_slots() must be called before pci_remove_root_bus(),
otherwise a general protection fault can happen, if the kernel is built
with the memory debugging options.
Fixes: 15becc2b56c6 ("PCI: hv: Add hv_pci_remove_slots() when we unload the driver")
Signed-off-by: Dexuan Cui <decui@xxxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
---
When pci-hyperv is unloaded, this panic can happen:
general protection fault:
CPU: 2 PID: 1091 Comm: rmmod Not tainted 5.2.0+
RIP: 0010:pci_slot_release+0x30/0xd0
Call Trace:
kobject_release+0x65/0x190
pci_destroy_slot+0x25/0x60
hv_pci_remove+0xec/0x110 [pci_hyperv]
vmbus_remove+0x20/0x30 [hv_vmbus]
device_release_driver_internal+0xd5/0x1b0
driver_detach+0x44/0x7c
bus_remove_driver+0x75/0xc7
vmbus_driver_unregister+0x50/0xbd [hv_vmbus]
__x64_sys_delete_module+0x136/0x200
do_syscall_64+0x5e/0x220
drivers/pci/controller/pci-hyperv.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/pci/controller/pci-hyperv.c b/drivers/pci/controller/pci-hyperv.c
index 6b9cc6e60a..68c611d 100644
--- a/drivers/pci/controller/pci-hyperv.c
+++ b/drivers/pci/controller/pci-hyperv.c
@@ -2757,8 +2757,8 @@ static int hv_pci_remove(struct hv_device *hdev)
/* Remove the bus from PCI's point of view. */
pci_lock_rescan_remove();
pci_stop_root_bus(hbus->pci_bus);
- pci_remove_root_bus(hbus->pci_bus);
hv_pci_remove_slots(hbus);
+ pci_remove_root_bus(hbus->pci_bus);
pci_unlock_rescan_remove();
hbus->state = hv_pcibus_removed;
}
--
1.8.3.1
