[lvc-project] [PATCH 5.10.y] PCI: Check parent for NULL in of_pci_bus_release_domain_nr()

[Sergey Shtylyov]

From: Sergey Shtylyov <s.shtylyov at auroraos.dev>

[ Upstream commit f7245901de8978d829f80b3d8e36ed9a8fd18049 ]

of_pci_bus_find_domain_nr() allows its parent parameter to be NULL but
of_pci_bus_release_domain_nr() (that undoes its effect) doesn't -- that
means it's going to blow up while calling of_get_pci_domain_nr() if the
parent parameter indeed happens to be NULL.  Add the missing NULL check.

Found by Linux Verification Center (linuxtesting.org) with the Svace static
analysis tool.

Fixes: c14f7ccc9f5d ("PCI: Assign PCI domain IDs by ida_alloc()")
Signed-off-by: Sergey Shtylyov <s.shtylyov at auroraos.dev>
Signed-off-by: Bjorn Helgaas <bhelgaas at google.com>
Link: https://patch.msgid.link/20260127203944.28588-1-s.shtylyov@auroraos.dev
---
 drivers/pci/pci.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Index: linux-stable/drivers/pci/pci.c
===================================================================
--- linux-stable.orig/drivers/pci/pci.c
+++ linux-stable/drivers/pci/pci.c
@@ -6533,7 +6533,7 @@ static void of_pci_bus_release_domain_nr
 		return;
 
 	/* Release domain from IDA where it was allocated. */
-	if (of_get_pci_domain_nr(parent->of_node) == bus->domain_nr)
+	if (parent && of_get_pci_domain_nr(parent->of_node) == bus->domain_nr)
 		ida_free(&pci_domain_nr_static_ida, bus->domain_nr);
 	else
 		ida_free(&pci_domain_nr_dynamic_ida, bus->domain_nr);