From: Zijun Hu <quic_zijuhu@xxxxxxxxxxx>
pci_epc_destroy() invokes pci_bus_release_domain_nr() to release domain_nr
ID, but the invocation has below 2 faults:
- The later accesses device @epc->dev which has been kfree()ed by previous
device_unregister(), namely, it is a UAF issue.
- The later frees the domain_nr ID into @epc->dev, but the ID is actually
allocated from @epc->dev.parent, so it will destroy domain_nr IDA.
Fix by freeing the ID to @epc->dev.parent before unregistering @epc->dev.
Fixes: 0328947c5032 ("PCI: endpoint: Assign PCI domain number for endpoint controllers")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Zijun Hu <quic_zijuhu@xxxxxxxxxxx>
---
drivers/pci/endpoint/pci-epc-core.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/drivers/pci/endpoint/pci-epc-core.c b/drivers/pci/endpoint/pci-epc-core.c
index 17f007109255..bcc9bc3d6df5 100644
--- a/drivers/pci/endpoint/pci-epc-core.c
+++ b/drivers/pci/endpoint/pci-epc-core.c
@@ -837,11 +837,10 @@ 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);
--
2.34.1
