linux-kernel - [PATCH -next 2/3] PCI: fix possible memory leak in error case in pci_register_host

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Message-ID: <20220825122753.1838930-2-yangyingliang@huawei.com>
Date:   Thu, 25 Aug 2022 20:27:52 +0800
From:   Yang Yingliang <yangyingliang@...wei.com>
To:     <linux-kernel@...r.kernel.org>, <linux-pci@...r.kernel.org>
CC:     <bhelgaas@...gle.com>
Subject: [PATCH -next 2/3] PCI: fix possible memory leak in error case in pci_register_host_bridge()

If device_register() fails in pci_register_host_bridge(), the refcount
of bus device is leaked, so device name that set by dev_set_name() can
not be freed. Fix this by calling put_device() when device_register()
fails, so the device name will be freed in kobject_cleanup().

Fixes: 37d6a0a6f470 ("PCI: Add pci_register_host_bridge() interface")
Signed-off-by: Yang Yingliang <yangyingliang@...wei.com>
---
 drivers/pci/probe.c | 17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)

diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index e500eb9d6468..292d9da146ce 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -948,8 +948,17 @@ static int pci_register_host_bridge(struct pci_host_bridge *bridge)
 	name = dev_name(&bus->dev);
 
 	err = device_register(&bus->dev);
-	if (err)
-		goto unregister;
+	if (err) {
+		/*
+		 * release_pcibus_dev() will decrease the refcount of bridge
+		 * device and free the memory of bus.
+		 * The memory of bus device name will be freed when the refcount
+		 * get to zero.
+		 */
+		put_device(&bus->dev);
+		device_unregister(&bridge->dev);
+		return err;
+	}
 
 	pcibios_add_bus(bus);
 
@@ -1025,10 +1034,6 @@ static int pci_register_host_bridge(struct pci_host_bridge *bridge)
 
 	return 0;
 
-unregister:
-	put_device(&bridge->dev);
-	device_unregister(&bridge->dev);
-
 free:
 	kfree(bus);
 	return err;
-- 
2.25.1