PCI: endpoint: Fix PCI domain ID release in pci_epc_destroy()

pci_epc_destroy() invokes pci_bus_release_domain_nr() to release the PCI
domain ID, but there are two issues:

  - 'epc->dev' is passed to pci_bus_release_domain_nr() which was already
    freed by device_unregister(), leading to a use-after-free issue.

  - Domain ID corresponds to the EPC device parent, so passing 'epc->dev'
    is also wrong.

Fix these issues by passing 'epc->dev.parent' to
pci_bus_release_domain_nr() and also do it before device_unregister().

Fixes: 0328947c5032 ("PCI: endpoint: Assign PCI domain number for endpoint controllers")
Signed-off-by: Zijun Hu <quic_zijuhu@quicinc.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/20241107-epc_rfc-v2-1-da5b6a99a66f@quicinc.com
[mani: reworded subject and description]
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Cc: stable@vger.kernel.org

diff --git a/drivers/pci/endpoint/pci-epc-core.c b/drivers/pci/endpoint/pci-epc-core.c
index 04a85d2f7e2a88912af77d20ae80d77105699bb6..21af2dbacc333b24a2947cc714fe4c201a46ec77 100644 (file)
--- a/drivers/pci/endpoint/pci-epc-core.c
+++ b/drivers/pci/endpoint/pci-epc-core.c
@@ -923,11 +923,10 @@ EXPORT_SYMBOL_GPL(pci_epc_bus_master_enable_notify);
 void pci_epc_destroy(struct pci_epc *epc)
 {
        pci_ep_cfs_remove_epc_group(epc->group);
-       device_unregister(&epc->dev);
-
 #ifdef CONFIG_PCI_DOMAINS_GENERIC
-       pci_bus_release_domain_nr(&epc->dev, epc->domain_nr);
+       pci_bus_release_domain_nr(epc->dev.parent, epc->domain_nr);
 #endif
+       device_unregister(&epc->dev);
 }
 EXPORT_SYMBOL_GPL(pci_epc_destroy);