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, 72 insertions, 0 deletions

diff --git a/include/crypto/b128ops.h b/include/crypto/b128ops.h
new file mode 100644
index 000000000..f3b37cbb3
--- /dev/null
+++ b/include/crypto/b128ops.h
@@ -0,0 +1,72 @@
+/* b128ops.h - common 128-bit block operations
+ *
+ * Copyright (c) 2003, Dr Brian Gladman, Worcester, UK.
+ * Copyright (c) 2006, Rik Snel <rsnel@cube.dyndns.org>
+ *
+ * Based on Dr Brian Gladman's (GPL'd) work published at
+ * http://fp.gladman.plus.com/cryptography_technology/index.htm
+ * See the original copyright notice below.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ */
+/*
+ ---------------------------------------------------------------------------
+ Copyright (c) 2003, Dr Brian Gladman, Worcester, UK.   All rights reserved.
+
+ LICENSE TERMS
+
+ The free distribution and use of this software in both source and binary
+ form is allowed (with or without changes) provided that:
+
+   1. distributions of this source code include the above copyright
+      notice, this list of conditions and the following disclaimer;
+
+   2. distributions in binary form include the above copyright
+      notice, this list of conditions and the following disclaimer
+      in the documentation and/or other associated materials;
+
+   3. the copyright holder's name is not used to endorse products
+      built using this software without specific written permission.
+
+ ALTERNATIVELY, provided that this notice is retained in full, this product
+ may be distributed under the terms of the GNU General Public License (GPL),
+ in which case the provisions of the GPL apply INSTEAD OF those given above.
+
+ DISCLAIMER
+
+ This software is provided 'as is' with no explicit or implied warranties
+ in respect of its properties, including, but not limited to, correctness
+ and/or fitness for purpose.
+ ---------------------------------------------------------------------------
+ Issue Date: 13/06/2006
+*/
+
+#ifndef _CRYPTO_B128OPS_H
+#define _CRYPTO_B128OPS_H
+
+#include <linux/types.h>
+
+typedef struct {
+	__be64 a, b;
+} be128;
+
+typedef struct {
+	__le64 b, a;
+} le128;
+
+static inline void be128_xor(be128 *r, const be128 *p, const be128 *q)
+{
+	r->a = p->a ^ q->a;
+	r->b = p->b ^ q->b;
+}
+
+static inline void le128_xor(le128 *r, const le128 *p, const le128 *q)
+{
+	r->a = p->a ^ q->a;
+	r->b = p->b ^ q->b;
+}
+
+#endif /* _CRYPTO_B128OPS_H */