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, 132 insertions, 0 deletions

diff --git a/net/wireless/nl80211.h b/net/wireless/nl80211.h
new file mode 100644
index 000000000..bdb065d14
--- /dev/null
+++ b/net/wireless/nl80211.h
@@ -0,0 +1,132 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Portions of this file
+ * Copyright (C) 2018, 2020-2026 Intel Corporation
+ */
+#ifndef __NET_WIRELESS_NL80211_H
+#define __NET_WIRELESS_NL80211_H
+
+#include "core.h"
+
+int nl80211_init(void);
+void nl80211_exit(void);
+
+void *nl80211hdr_put(struct sk_buff *skb, u32 portid, u32 seq,
+		     int flags, u8 cmd);
+bool nl80211_put_sta_rate(struct sk_buff *msg, struct rate_info *info,
+			  int attr);
+
+static inline u64 wdev_id(struct wireless_dev *wdev)
+{
+	return (u64)wdev->identifier |
+	       ((u64)wiphy_to_rdev(wdev->wiphy)->wiphy_idx << 32);
+}
+
+int nl80211_parse_chandef(struct cfg80211_registered_device *rdev,
+			  struct netlink_ext_ack *extack,
+			  struct nlattr **attrs,
+			  struct cfg80211_chan_def *chandef,
+			  bool npca_permitted);
+int nl80211_parse_random_mac(struct nlattr **attrs,
+			     u8 *mac_addr, u8 *mac_addr_mask);
+
+void nl80211_notify_wiphy(struct cfg80211_registered_device *rdev,
+			  enum nl80211_commands cmd);
+void nl80211_notify_iface(struct cfg80211_registered_device *rdev,
+			  struct wireless_dev *wdev,
+			  enum nl80211_commands cmd);
+void nl80211_send_scan_start(struct cfg80211_registered_device *rdev,
+			     struct wireless_dev *wdev);
+struct sk_buff *nl80211_build_scan_msg(struct cfg80211_registered_device *rdev,
+				       struct wireless_dev *wdev, bool aborted);
+void nl80211_send_scan_msg(struct cfg80211_registered_device *rdev,
+			   struct sk_buff *msg);
+void nl80211_send_sched_scan(struct cfg80211_sched_scan_request *req, u32 cmd);
+void nl80211_common_reg_change_event(enum nl80211_commands cmd_id,
+				     struct regulatory_request *request);
+
+static inline void
+nl80211_send_reg_change_event(struct regulatory_request *request)
+{
+	nl80211_common_reg_change_event(NL80211_CMD_REG_CHANGE, request);
+}
+
+static inline void
+nl80211_send_wiphy_reg_change_event(struct regulatory_request *request)
+{
+	nl80211_common_reg_change_event(NL80211_CMD_WIPHY_REG_CHANGE, request);
+}
+
+void nl80211_send_rx_auth(struct cfg80211_registered_device *rdev,
+			  struct net_device *netdev,
+			  const u8 *buf, size_t len, gfp_t gfp);
+void nl80211_send_rx_assoc(struct cfg80211_registered_device *rdev,
+			   struct net_device *netdev,
+			   const struct cfg80211_rx_assoc_resp_data *data);
+void nl80211_send_deauth(struct cfg80211_registered_device *rdev,
+			 struct net_device *netdev,
+			 const u8 *buf, size_t len,
+			 bool reconnect, gfp_t gfp);
+void nl80211_send_disassoc(struct cfg80211_registered_device *rdev,
+			   struct net_device *netdev,
+			   const u8 *buf, size_t len,
+			   bool reconnect, gfp_t gfp);
+void nl80211_send_auth_timeout(struct cfg80211_registered_device *rdev,
+			       struct net_device *netdev,
+			       const u8 *addr, gfp_t gfp);
+void nl80211_send_assoc_timeout(struct cfg80211_registered_device *rdev,
+				struct net_device *netdev,
+				const u8 *addr, gfp_t gfp);
+void nl80211_send_connect_result(struct cfg80211_registered_device *rdev,
+				 struct net_device *netdev,
+				 struct cfg80211_connect_resp_params *params,
+				 gfp_t gfp);
+void nl80211_send_roamed(struct cfg80211_registered_device *rdev,
+			 struct net_device *netdev,
+			 struct cfg80211_roam_info *info, gfp_t gfp);
+/* For STA/GC, indicate port authorized with AP/GO bssid.
+ * For GO/AP, use peer GC/STA mac_addr.
+ */
+void nl80211_send_port_authorized(struct cfg80211_registered_device *rdev,
+				  struct net_device *netdev, const u8 *peer_addr,
+				  const u8 *td_bitmap, u8 td_bitmap_len);
+void nl80211_send_disconnected(struct cfg80211_registered_device *rdev,
+			       struct net_device *netdev, u16 reason,
+			       const u8 *ie, size_t ie_len, bool from_ap);
+
+void
+nl80211_michael_mic_failure(struct cfg80211_registered_device *rdev,
+			    struct net_device *netdev, const u8 *addr,
+			    enum nl80211_key_type key_type,
+			    int key_id, const u8 *tsc, gfp_t gfp);
+
+void
+nl80211_send_beacon_hint_event(struct wiphy *wiphy,
+			       struct ieee80211_channel *channel_before,
+			       struct ieee80211_channel *channel_after);
+
+void nl80211_send_ibss_bssid(struct cfg80211_registered_device *rdev,
+			     struct net_device *netdev, const u8 *bssid,
+			     gfp_t gfp);
+
+int nl80211_send_mgmt(struct cfg80211_registered_device *rdev,
+		      struct wireless_dev *wdev, u32 nlpid,
+		      struct cfg80211_rx_info *info, gfp_t gfp);
+
+void
+nl80211_radar_notify(struct cfg80211_registered_device *rdev,
+		     const struct cfg80211_chan_def *chandef,
+		     enum nl80211_radar_event event,
+		     struct net_device *netdev, gfp_t gfp);
+
+void nl80211_send_ap_stopped(struct wireless_dev *wdev, unsigned int link_id);
+
+void cfg80211_free_coalesce(struct cfg80211_coalesce *coalesce);
+
+/* peer measurement */
+int nl80211_pmsr_start(struct sk_buff *skb, struct genl_info *info);
+
+void nl80211_mlo_reconf_add_done(struct net_device *dev,
+				 struct cfg80211_mlo_reconf_done_data *data);
+
+#endif /* __NET_WIRELESS_NL80211_H */