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, 34 insertions, 0 deletions

diff --git a/include/crypto/authenc.h b/include/crypto/authenc.h
new file mode 100644
index 000000000..15a9caa23
--- /dev/null
+++ b/include/crypto/authenc.h
@@ -0,0 +1,34 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Authenc: Simple AEAD wrapper for IPsec
+ *
+ * Copyright (c) 2007 Herbert Xu <herbert@gondor.apana.org.au>
+ */
+#ifndef _CRYPTO_AUTHENC_H
+#define _CRYPTO_AUTHENC_H
+
+#include <linux/types.h>
+
+enum {
+	CRYPTO_AUTHENC_KEYA_UNSPEC,
+	CRYPTO_AUTHENC_KEYA_PARAM,
+};
+
+struct crypto_authenc_key_param {
+	__be32 enckeylen;
+};
+
+struct crypto_authenc_keys {
+	const u8 *authkey;
+	const u8 *enckey;
+
+	unsigned int authkeylen;
+	unsigned int enckeylen;
+};
+
+int crypto_authenc_extractkeys(struct crypto_authenc_keys *keys, const u8 *key,
+			       unsigned int keylen);
+int crypto_krb5enc_extractkeys(struct crypto_authenc_keys *keys, const u8 *key,
+			       unsigned int keylen);
+
+#endif	/* _CRYPTO_AUTHENC_H */