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, 61 insertions, 0 deletions

diff --git a/include/net/wext.h b/include/net/wext.h
new file mode 100644
index 000000000..aa192a670
--- /dev/null
+++ b/include/net/wext.h
@@ -0,0 +1,61 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __NET_WEXT_H
+#define __NET_WEXT_H
+
+#include <net/iw_handler.h>
+
+struct net;
+
+#ifdef CONFIG_WEXT_CORE
+int wext_handle_ioctl(struct net *net, unsigned int cmd,
+		      void __user *arg);
+int compat_wext_handle_ioctl(struct net *net, unsigned int cmd,
+			     unsigned long arg);
+
+struct iw_statistics *get_wireless_stats(struct net_device *dev);
+int call_commit_handler(struct net_device *dev);
+#else
+static inline int wext_handle_ioctl(struct net *net, unsigned int cmd,
+				    void __user *arg)
+{
+	return -EINVAL;
+}
+static inline int compat_wext_handle_ioctl(struct net *net, unsigned int cmd,
+					   unsigned long arg)
+{
+	return -EINVAL;
+}
+#endif
+
+#ifdef CONFIG_WEXT_PROC
+int wext_proc_init(struct net *net);
+void wext_proc_exit(struct net *net);
+#else
+static inline int wext_proc_init(struct net *net)
+{
+	return 0;
+}
+static inline void wext_proc_exit(struct net *net)
+{
+	return;
+}
+#endif
+
+#ifdef CONFIG_WEXT_PRIV
+int ioctl_private_call(struct net_device *dev, struct iwreq *iwr,
+		       unsigned int cmd, struct iw_request_info *info,
+		       iw_handler handler);
+int compat_private_call(struct net_device *dev, struct iwreq *iwr,
+			unsigned int cmd, struct iw_request_info *info,
+			iw_handler handler);
+int iw_handler_get_private(struct net_device *		dev,
+			   struct iw_request_info *	info,
+			   union iwreq_data *		wrqu,
+			   char *			extra);
+#else
+#define ioctl_private_call NULL
+#define compat_private_call NULL
+#endif
+
+
+#endif /* __NET_WEXT_H */