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, 43 insertions, 0 deletions

diff --git a/net/batman-adv/mesh-interface.h b/net/batman-adv/mesh-interface.h
new file mode 100644
index 000000000..5e1e83e04
--- /dev/null
+++ b/net/batman-adv/mesh-interface.h
@@ -0,0 +1,43 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (C) B.A.T.M.A.N. contributors:
+ *
+ * Marek Lindner
+ */
+
+#ifndef _NET_BATMAN_ADV_MESH_INTERFACE_H_
+#define _NET_BATMAN_ADV_MESH_INTERFACE_H_
+
+#include "main.h"
+
+#include <linux/kref.h>
+#include <linux/netdevice.h>
+#include <linux/skbuff.h>
+#include <linux/types.h>
+
+int batadv_skb_head_push(struct sk_buff *skb, unsigned int len);
+void batadv_interface_rx(struct net_device *mesh_iface,
+			 struct sk_buff *skb, int hdr_size,
+			 struct batadv_orig_node *orig_node);
+bool batadv_meshif_is_valid(const struct net_device *net_dev);
+extern struct rtnl_link_ops batadv_link_ops;
+int batadv_meshif_create_vlan(struct batadv_priv *bat_priv, unsigned short vid);
+void batadv_meshif_destroy_vlan(struct batadv_priv *bat_priv,
+				struct batadv_meshif_vlan *vlan);
+void batadv_meshif_vlan_release(struct kref *ref);
+struct batadv_meshif_vlan *batadv_meshif_vlan_get(struct batadv_priv *bat_priv,
+						  unsigned short vid);
+
+/**
+ * batadv_meshif_vlan_put() - decrease the vlan object refcounter and
+ *  possibly release it
+ * @vlan: the vlan object to release
+ */
+static inline void batadv_meshif_vlan_put(struct batadv_meshif_vlan *vlan)
+{
+	if (!vlan)
+		return;
+
+	kref_put(&vlan->refcount, batadv_meshif_vlan_release);
+}
+
+#endif /* _NET_BATMAN_ADV_MESH_INTERFACE_H_ */