x86/amd_node: Fix PCI device reference counting in amd_smn_init()grafted

The local "root" pointer is a temporary variable used during the device
search. Therefore, refcount related to the search iterators should be cleaned
up after the search is complete.

Use the __free() cleanup macro to ensure the refcount is decremented when the
temporary pointer goes out of scope.

Additionally, increment the refcount when caching a root pointer. This ensures
the in-use refcount is separate from the temporary search refcounting.

Finally, drop the redundant "root = NULL" before the second search loop. The
pci_get_class() iterator always decrements the refcount of its "from"
argument, so the first loop can only fall through with "root" already NULL.

Fixes: 0a4b61d9c2e4 ("x86/amd_node: Fix AMD root device caching")
Closes: https://sashiko.dev/#/patchset/20260806160159.230453-1-jason.andryuk%40amd.com
Reported-by: Sashiko <sashiko-bot@kernel.org>
Assisted-by: LLM
Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Mario Limonciello (AMD) <superm1@kernel.org>
Cc: <stable@kernel.org>
Link: https://patch.msgid.link/20260903154325.74343-1-yazen.ghannam@amd.com

1 files changed, 44 insertions, 0 deletions

diff --git a/drivers/net/usb/Makefile b/drivers/net/usb/Makefile
new file mode 100644
index 000000000..4964f7b32
--- /dev/null
+++ b/drivers/net/usb/Makefile
@@ -0,0 +1,44 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for USB Network drivers
+#
+
+obj-$(CONFIG_USB_CATC)		+= catc.o
+obj-$(CONFIG_USB_KAWETH)	+= kaweth.o
+obj-$(CONFIG_USB_PEGASUS)	+= pegasus.o
+obj-$(CONFIG_USB_RTL8150)	+= rtl8150.o
+obj-$(CONFIG_USB_RTL8152)	+= r8152.o
+obj-$(CONFIG_USB_HSO)		+= hso.o
+obj-$(CONFIG_USB_LAN78XX)	+= lan78xx.o
+obj-$(CONFIG_USB_NET_AX8817X)	+= asix.o
+asix-y := asix_devices.o asix_common.o ax88172a.o
+obj-$(CONFIG_USB_NET_AX88179_178A)      += ax88179_178a.o
+obj-$(CONFIG_USB_NET_CDCETHER)	+= cdc_ether.o
+obj-$(CONFIG_USB_NET_CDC_EEM)	+= cdc_eem.o
+obj-$(CONFIG_USB_NET_DM9601)	+= dm9601.o
+obj-$(CONFIG_USB_NET_SR9700)	+= sr9700.o
+obj-$(CONFIG_USB_NET_SR9800)	+= sr9800.o
+obj-$(CONFIG_USB_NET_SMSC75XX)	+= smsc75xx.o
+obj-$(CONFIG_USB_NET_SMSC95XX)	+= smsc95xx.o
+obj-$(CONFIG_USB_NET_GL620A)	+= gl620a.o
+obj-$(CONFIG_USB_NET_NET1080)	+= net1080.o
+obj-$(CONFIG_USB_NET_PLUSB)	+= plusb.o
+obj-$(CONFIG_USB_NET_RNDIS_HOST)	+= rndis_host.o
+obj-$(CONFIG_USB_NET_CDC_SUBSET_ENABLE)	+= cdc_subset.o
+obj-$(CONFIG_USB_NET_ZAURUS)	+= zaurus.o
+obj-$(CONFIG_USB_NET_MCS7830)	+= mcs7830.o
+obj-$(CONFIG_USB_USBNET)	+= usbnet.o
+obj-$(CONFIG_USB_NET_INT51X1)	+= int51x1.o
+obj-$(CONFIG_USB_CDC_PHONET)	+= cdc-phonet.o
+obj-$(CONFIG_USB_NET_KALMIA)	+= kalmia.o
+obj-$(CONFIG_USB_IPHETH)	+= ipheth.o
+obj-$(CONFIG_USB_SIERRA_NET)	+= sierra_net.o
+obj-$(CONFIG_USB_NET_CX82310_ETH)	+= cx82310_eth.o
+obj-$(CONFIG_USB_NET_CDC_NCM)	+= cdc_ncm.o
+obj-$(CONFIG_USB_NET_HUAWEI_CDC_NCM)	+= huawei_cdc_ncm.o
+obj-$(CONFIG_USB_VL600)		+= lg-vl600.o
+obj-$(CONFIG_USB_NET_QMI_WWAN)	+= qmi_wwan.o
+obj-$(CONFIG_USB_NET_CDC_MBIM)	+= cdc_mbim.o
+obj-$(CONFIG_USB_NET_CH9200)	+= ch9200.o
+obj-$(CONFIG_USB_NET_AQC111)	+= aqc111.o
+obj-$(CONFIG_USB_RTL8153_ECM)	+= r8153_ecm.o