[PATCH 3/3] PCI: thunder-pem, hisi, thunder-ecam: Fix ECAM config window use-after-free

[Hongyan Xu]

thunder-pem, hisi and thunder-ecam set .probe = pci_host_common_probe but
have no ->remove, so unbinding only runs devres_release_all():
gen_pci_unmap_cfg() -> pci_ecam_free() frees the ECAM config window while
the bus tree stays registered - only pci_remove_bus() unlinks a bus, and
only pci_host_common_remove() reaches it for a root bus.  The next config
access in pci_ecam_map_bus() reads cfg->ops->bus_shift.
Trigger: DT overlay removal of the node that supplied or enabled it.

Fix: give each driver the same .remove = pci_host_common_remove that
pci-host-generic.c got in commit 01fcb7f777a9 ("PCI: Add support for
unbinding the generic PCI host controller"), so the unlink comes first.

Fixes: f12b76e56ada ("PCI: thunder: Add PCIe host driver for ThunderX processors")
Fixes: a2ec1996098c ("PCI: hisi: Add DT almost-ECAM support for Hip06/Hip07 host controllers")
Fixes: 7b6e7ba8e81a ("PCI: thunder: Add driver for ThunderX-pass{1,2} on-chip devices")
Cc: stable at vger.kernel.org
Signed-off-by: Hongyan Xu <getshell at seu.edu.cn>
---
 drivers/pci/controller/dwc/pcie-hisi.c    | 1 +
 drivers/pci/controller/pci-thunder-ecam.c | 1 +
 drivers/pci/controller/pci-thunder-pem.c  | 1 +
 3 files changed, 3 insertions(+)

diff --git a/drivers/pci/controller/dwc/pcie-hisi.c b/drivers/pci/controller/dwc/pcie-hisi.c
index 3c17897e56fc..5ed58e5db797 100644
--- a/drivers/pci/controller/dwc/pcie-hisi.c
+++ b/drivers/pci/controller/dwc/pcie-hisi.c
@@ -169,6 +169,7 @@ static const struct of_device_id hisi_pcie_almost_ecam_of_match[] = {
 
 static struct platform_driver hisi_pcie_almost_ecam_driver = {
 	.probe  = pci_host_common_probe,
+	.remove = pci_host_common_remove,
 	.driver = {
 		   .name = "hisi-pcie-almost-ecam",
 		   .of_match_table = hisi_pcie_almost_ecam_of_match,
diff --git a/drivers/pci/controller/pci-thunder-ecam.c b/drivers/pci/controller/pci-thunder-ecam.c
index b5b4a958e6a2..4745f5d00b5a 100644
--- a/drivers/pci/controller/pci-thunder-ecam.c
+++ b/drivers/pci/controller/pci-thunder-ecam.c
@@ -358,6 +358,7 @@ static struct platform_driver thunder_ecam_driver = {
 		.suppress_bind_attrs = true,
 	},
 	.probe = pci_host_common_probe,
+	.remove = pci_host_common_remove,
 };
 builtin_platform_driver(thunder_ecam_driver);
 
diff --git a/drivers/pci/controller/pci-thunder-pem.c b/drivers/pci/controller/pci-thunder-pem.c
index 5fa037fb61dc..80cabbf263be 100644
--- a/drivers/pci/controller/pci-thunder-pem.c
+++ b/drivers/pci/controller/pci-thunder-pem.c
@@ -474,6 +474,7 @@ static struct platform_driver thunder_pem_driver = {
 		.suppress_bind_attrs = true,
 	},
 	.probe = pci_host_common_probe,
+	.remove = pci_host_common_remove,
 };
 builtin_platform_driver(thunder_pem_driver);
 
-- 
2.50.1.windows.1