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, 71 insertions, 0 deletions

diff --git a/net/mac80211/Makefile b/net/mac80211/Makefile
new file mode 100644
index 000000000..36f1e3e22
--- /dev/null
+++ b/net/mac80211/Makefile
@@ -0,0 +1,71 @@
+# SPDX-License-Identifier: GPL-2.0
+obj-$(CONFIG_MAC80211) += mac80211.o
+
+# mac80211 objects
+mac80211-y := \
+	main.o status.o \
+	driver-ops.o \
+	sta_info.o \
+	wep.o \
+	aead_api.o \
+	wpa.o \
+	scan.o offchannel.o \
+	ht.o agg-tx.o agg-rx.o \
+	vht.o \
+	he.o \
+	s1g.o \
+	ibss.o \
+	iface.o \
+	link.o \
+	rate.o \
+	tkip.o \
+	aes_cmac.o \
+	aes_gmac.o \
+	fils_aead.o \
+	cfg.o \
+	ethtool.o \
+	rx.o \
+	spectmgmt.o \
+	tx.o \
+	key.o \
+	util.o parse.o \
+	wme.o \
+	chan.o ap.o \
+	trace.o mlme.o \
+	tdls.o \
+	ocb.o \
+	airtime.o \
+	eht.o uhr.o nan.o
+
+mac80211-$(CONFIG_MAC80211_LEDS) += led.o
+mac80211-$(CONFIG_MAC80211_DEBUGFS) += \
+	debugfs.o \
+	debugfs_sta.o \
+	debugfs_netdev.o \
+	debugfs_key.o
+
+mac80211-$(CONFIG_MAC80211_MESH) += \
+	mesh.o \
+	mesh_pathtbl.o \
+	mesh_plink.o \
+	mesh_hwmp.o \
+	mesh_sync.o \
+	mesh_ps.o
+
+mac80211-$(CONFIG_PM) += pm.o
+
+CFLAGS_trace.o := -I$(src)
+
+rc80211_minstrel-y := \
+	rc80211_minstrel_ht.o
+
+rc80211_minstrel-$(CONFIG_MAC80211_DEBUGFS) += \
+	rc80211_minstrel_ht_debugfs.o
+
+mac80211-$(CONFIG_MAC80211_RC_MINSTREL) += $(rc80211_minstrel-y)
+
+obj-y += tests/
+
+mac80211-y += wbrf.o
+
+ccflags-y += -DDEBUG