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, 219 insertions, 0 deletions

diff --git a/net/mac802154/mib.c b/net/mac802154/mib.c
new file mode 100644
index 000000000..81666e1d7
--- /dev/null
+++ b/net/mac802154/mib.c
@@ -0,0 +1,219 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright 2007-2012 Siemens AG
+ *
+ * Written by:
+ * Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
+ * Sergey Lapin <slapin@ossfans.org>
+ * Maxim Gorbachyov <maxim.gorbachev@siemens.com>
+ * Alexander Smirnov <alex.bluesman.smirnov@gmail.com>
+ */
+
+#include <linux/if_arp.h>
+
+#include <net/mac802154.h>
+#include <net/ieee802154_netdev.h>
+#include <net/cfg802154.h>
+
+#include "ieee802154_i.h"
+#include "driver-ops.h"
+
+void mac802154_dev_set_page_channel(struct net_device *dev, u8 page, u8 chan)
+{
+	struct ieee802154_sub_if_data *sdata = IEEE802154_DEV_TO_SUB_IF(dev);
+	struct ieee802154_local *local = sdata->local;
+	int res;
+
+	ASSERT_RTNL();
+
+	BUG_ON(dev->type != ARPHRD_IEEE802154);
+
+	res = drv_set_channel(local, page, chan);
+	if (res) {
+		pr_debug("set_channel failed\n");
+	} else {
+		local->phy->current_channel = chan;
+		local->phy->current_page = page;
+	}
+}
+
+int mac802154_get_params(struct net_device *dev,
+			 struct ieee802154_llsec_params *params)
+{
+	struct ieee802154_sub_if_data *sdata = IEEE802154_DEV_TO_SUB_IF(dev);
+	int res;
+
+	BUG_ON(dev->type != ARPHRD_IEEE802154);
+
+	mutex_lock(&sdata->sec_mtx);
+	res = mac802154_llsec_get_params(&sdata->sec, params);
+	mutex_unlock(&sdata->sec_mtx);
+
+	return res;
+}
+
+int mac802154_set_params(struct net_device *dev,
+			 const struct ieee802154_llsec_params *params,
+			 int changed)
+{
+	struct ieee802154_sub_if_data *sdata = IEEE802154_DEV_TO_SUB_IF(dev);
+	int res;
+
+	BUG_ON(dev->type != ARPHRD_IEEE802154);
+
+	mutex_lock(&sdata->sec_mtx);
+	res = mac802154_llsec_set_params(&sdata->sec, params, changed);
+	mutex_unlock(&sdata->sec_mtx);
+
+	return res;
+}
+
+int mac802154_add_key(struct net_device *dev,
+		      const struct ieee802154_llsec_key_id *id,
+		      const struct ieee802154_llsec_key *key)
+{
+	struct ieee802154_sub_if_data *sdata = IEEE802154_DEV_TO_SUB_IF(dev);
+	int res;
+
+	BUG_ON(dev->type != ARPHRD_IEEE802154);
+
+	mutex_lock(&sdata->sec_mtx);
+	res = mac802154_llsec_key_add(&sdata->sec, id, key);
+	mutex_unlock(&sdata->sec_mtx);
+
+	return res;
+}
+
+int mac802154_del_key(struct net_device *dev,
+		      const struct ieee802154_llsec_key_id *id)
+{
+	struct ieee802154_sub_if_data *sdata = IEEE802154_DEV_TO_SUB_IF(dev);
+	int res;
+
+	BUG_ON(dev->type != ARPHRD_IEEE802154);
+
+	mutex_lock(&sdata->sec_mtx);
+	res = mac802154_llsec_key_del(&sdata->sec, id);
+	mutex_unlock(&sdata->sec_mtx);
+
+	return res;
+}
+
+int mac802154_add_dev(struct net_device *dev,
+		      const struct ieee802154_llsec_device *llsec_dev)
+{
+	struct ieee802154_sub_if_data *sdata = IEEE802154_DEV_TO_SUB_IF(dev);
+	int res;
+
+	BUG_ON(dev->type != ARPHRD_IEEE802154);
+
+	mutex_lock(&sdata->sec_mtx);
+	res = mac802154_llsec_dev_add(&sdata->sec, llsec_dev);
+	mutex_unlock(&sdata->sec_mtx);
+
+	return res;
+}
+
+int mac802154_del_dev(struct net_device *dev, __le64 dev_addr)
+{
+	struct ieee802154_sub_if_data *sdata = IEEE802154_DEV_TO_SUB_IF(dev);
+	int res;
+
+	BUG_ON(dev->type != ARPHRD_IEEE802154);
+
+	mutex_lock(&sdata->sec_mtx);
+	res = mac802154_llsec_dev_del(&sdata->sec, dev_addr);
+	mutex_unlock(&sdata->sec_mtx);
+
+	return res;
+}
+
+int mac802154_add_devkey(struct net_device *dev,
+			 __le64 device_addr,
+			 const struct ieee802154_llsec_device_key *key)
+{
+	struct ieee802154_sub_if_data *sdata = IEEE802154_DEV_TO_SUB_IF(dev);
+	int res;
+
+	BUG_ON(dev->type != ARPHRD_IEEE802154);
+
+	mutex_lock(&sdata->sec_mtx);
+	res = mac802154_llsec_devkey_add(&sdata->sec, device_addr, key);
+	mutex_unlock(&sdata->sec_mtx);
+
+	return res;
+}
+
+int mac802154_del_devkey(struct net_device *dev,
+			 __le64 device_addr,
+			 const struct ieee802154_llsec_device_key *key)
+{
+	struct ieee802154_sub_if_data *sdata = IEEE802154_DEV_TO_SUB_IF(dev);
+	int res;
+
+	BUG_ON(dev->type != ARPHRD_IEEE802154);
+
+	mutex_lock(&sdata->sec_mtx);
+	res = mac802154_llsec_devkey_del(&sdata->sec, device_addr, key);
+	mutex_unlock(&sdata->sec_mtx);
+
+	return res;
+}
+
+int mac802154_add_seclevel(struct net_device *dev,
+			   const struct ieee802154_llsec_seclevel *sl)
+{
+	struct ieee802154_sub_if_data *sdata = IEEE802154_DEV_TO_SUB_IF(dev);
+	int res;
+
+	BUG_ON(dev->type != ARPHRD_IEEE802154);
+
+	mutex_lock(&sdata->sec_mtx);
+	res = mac802154_llsec_seclevel_add(&sdata->sec, sl);
+	mutex_unlock(&sdata->sec_mtx);
+
+	return res;
+}
+
+int mac802154_del_seclevel(struct net_device *dev,
+			   const struct ieee802154_llsec_seclevel *sl)
+{
+	struct ieee802154_sub_if_data *sdata = IEEE802154_DEV_TO_SUB_IF(dev);
+	int res;
+
+	BUG_ON(dev->type != ARPHRD_IEEE802154);
+
+	mutex_lock(&sdata->sec_mtx);
+	res = mac802154_llsec_seclevel_del(&sdata->sec, sl);
+	mutex_unlock(&sdata->sec_mtx);
+
+	return res;
+}
+
+void mac802154_lock_table(struct net_device *dev)
+{
+	struct ieee802154_sub_if_data *sdata = IEEE802154_DEV_TO_SUB_IF(dev);
+
+	BUG_ON(dev->type != ARPHRD_IEEE802154);
+
+	mutex_lock(&sdata->sec_mtx);
+}
+
+void mac802154_get_table(struct net_device *dev,
+			 struct ieee802154_llsec_table **t)
+{
+	struct ieee802154_sub_if_data *sdata = IEEE802154_DEV_TO_SUB_IF(dev);
+
+	BUG_ON(dev->type != ARPHRD_IEEE802154);
+
+	*t = &sdata->sec.table;
+}
+
+void mac802154_unlock_table(struct net_device *dev)
+{
+	struct ieee802154_sub_if_data *sdata = IEEE802154_DEV_TO_SUB_IF(dev);
+
+	BUG_ON(dev->type != ARPHRD_IEEE802154);
+
+	mutex_unlock(&sdata->sec_mtx);
+}