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, 94 insertions, 0 deletions

diff --git a/net/rxrpc/insecure.c b/net/rxrpc/insecure.c
new file mode 100644
index 000000000..0b39046bd
--- /dev/null
+++ b/net/rxrpc/insecure.c
@@ -0,0 +1,94 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* Null security operations.
+ *
+ * Copyright (C) 2016 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#include <net/af_rxrpc.h>
+#include "ar-internal.h"
+
+static int none_init_connection_security(struct rxrpc_connection *conn,
+					 struct rxrpc_key_token *token)
+{
+	return 0;
+}
+
+/*
+ * Allocate an appropriately sized buffer for the amount of data remaining.
+ */
+static struct rxrpc_txbuf *none_alloc_txbuf(struct rxrpc_call *call, size_t remain, gfp_t gfp)
+{
+	return rxrpc_alloc_data_txbuf(call, umin(remain, RXRPC_JUMBO_DATALEN), 1, gfp);
+}
+
+static int none_secure_packet(struct rxrpc_call *call, struct rxrpc_txbuf *txb)
+{
+	txb->pkt_len = txb->len;
+	if (txb->len == RXRPC_JUMBO_DATALEN)
+		txb->jumboable = true;
+	return 0;
+}
+
+static int none_verify_packet(struct rxrpc_call *call, struct sk_buff *skb)
+{
+	return 0;
+}
+
+static void none_free_call_crypto(struct rxrpc_call *call)
+{
+}
+
+static bool none_validate_challenge(struct rxrpc_connection *conn,
+				    struct sk_buff *skb)
+{
+	rxrpc_abort_conn(conn, skb, RX_PROTOCOL_ERROR, -EPROTO,
+			 rxrpc_eproto_rxnull_challenge);
+	return true;
+}
+
+static int none_sendmsg_respond_to_challenge(struct sk_buff *challenge,
+					     struct msghdr *msg)
+{
+	return -EINVAL;
+}
+
+static int none_verify_response(struct rxrpc_connection *conn,
+				struct sk_buff *response_skb,
+				void *response, unsigned int len)
+{
+	return rxrpc_abort_conn(conn, response_skb, RX_PROTOCOL_ERROR, -EPROTO,
+				rxrpc_eproto_rxnull_response);
+}
+
+static void none_clear(struct rxrpc_connection *conn)
+{
+}
+
+static int none_init(void)
+{
+	return 0;
+}
+
+static void none_exit(void)
+{
+}
+
+/*
+ * RxRPC Kerberos-based security
+ */
+const struct rxrpc_security rxrpc_no_security = {
+	.name				= "none",
+	.security_index			= RXRPC_SECURITY_NONE,
+	.init				= none_init,
+	.exit				= none_exit,
+	.init_connection_security	= none_init_connection_security,
+	.free_call_crypto		= none_free_call_crypto,
+	.alloc_txbuf			= none_alloc_txbuf,
+	.secure_packet			= none_secure_packet,
+	.verify_packet			= none_verify_packet,
+	.validate_challenge		= none_validate_challenge,
+	.sendmsg_respond_to_challenge	= none_sendmsg_respond_to_challenge,
+	.verify_response		= none_verify_response,
+	.clear				= none_clear,
+};