[PATCH 5.3 054/148] PCI: hv: Avoid use of hv_pci_dev->pci_slot after freeing it

From: Greg Kroah-Hartman
Date: Thu Oct 10 2019 - 04:39:56 EST


From: Dexuan Cui <decui@xxxxxxxxxxxxx>

commit 533ca1feed98b0bf024779a14760694c7cb4d431 upstream.

The slot must be removed before the pci_dev is removed, otherwise a panic
can happen due to use-after-free.

Fixes: 15becc2b56c6 ("PCI: hv: Add hv_pci_remove_slots() when we unload the driver")
Signed-off-by: Dexuan Cui <decui@xxxxxxxxxxxxx>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/pci/controller/pci-hyperv.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/pci/controller/pci-hyperv.c
+++ b/drivers/pci/controller/pci-hyperv.c
@@ -2701,8 +2701,8 @@ static int hv_pci_remove(struct hv_devic
/* 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;
}