FAILED: patch "[PATCH] PCI: Fix reference leak in pci_register_host_bridge()" failed to apply to 5.15-stable tree

The patch below does not apply to the 5.15-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y
git checkout FETCH_HEAD
git cherry-pick -x 804443c1f27883926de94c849d91f5b7d7d696e9
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<[email protected]>' --in-reply-to '2025041711-uptight-kept-0d4b@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..

Possible dependencies:

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 804443c1f27883926de94c849d91f5b7d7d696e9 Mon Sep 17 00:00:00 2001
From: Ma Ke <[email protected]>
Date: Tue, 25 Feb 2025 10:14:40 +0800
Subject: [PATCH] PCI: Fix reference leak in pci_register_host_bridge()

If device_register() fails, call put_device() to give up the reference to avoid a memory leak, per the comment at device_register().

Found by code review.

[bhelgaas: squash Dan Carpenter's double free fix from
https://lore.kernel.org/r/[email protected]]

index 5f04b8d9c736..dc37a3c0a977 100644
@@ -953,6 +953,7 @@ static int pci_register_host_bridge(struct pci_host_bridge *bridge)
 	resource_size_t offset, next_offset;
 	LIST_HEAD(resources);
 	struct resource *res, *next_res;
+	bool bus_registered = false;
 	char addr[64], *fmt;
 	const char *name;
 	int err;

@@ -1017,6 +1018,7 @@ static int pci_register_host_bridge(struct pci_host_bridge *bridge)
 	name = dev_name(&bus->dev);
 
 	err = device_register(&bus->dev);
+	bus_registered = true;
 	if (err)
 		goto unregister;
 

@@ -1103,12 +1105,15 @@ static int pci_register_host_bridge(struct pci_host_bridge *bridge)
 unregister:
 	put_device(&bridge->dev);
 	device_del(&bridge->dev);
-
 free:
 #ifdef CONFIG_PCI_DOMAINS_GENERIC
 	pci_bus_release_domain_nr(parent, bus->domain_nr);
 #endif
-	kfree(bus);
+	if (bus_registered)
+		put_device(&bus->dev);
+	else
+		kfree(bus);
+
 	return err;
 }