[PATCH 4.14 023/185] PCI: hv: Avoid use of hv_pci_dev->pci_slot after freeing it

From: Greg Kroah-Hartman
Date: Thu Oct 03 2019 - 13:33:55 EST


From: Dexuan Cui <decui@xxxxxxxxxxxxx>

[ Upstream commit 533ca1feed98b0bf024779a14760694c7cb4d431 ]

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: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/pci/host/pci-hyperv.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/pci/host/pci-hyperv.c b/drivers/pci/host/pci-hyperv.c
index 5a9d945122327..70825689e5a08 100644
--- a/drivers/pci/host/pci-hyperv.c
+++ b/drivers/pci/host/pci-hyperv.c
@@ -2740,8 +2740,8 @@ 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;
}
--
2.20.1