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, 100 insertions, 0 deletions

diff --git a/include/net/netns/conntrack.h b/include/net/netns/conntrack.h
new file mode 100644
index 000000000..ab74b5ed0
--- /dev/null
+++ b/include/net/netns/conntrack.h
@@ -0,0 +1,100 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __NETNS_CONNTRACK_H
+#define __NETNS_CONNTRACK_H
+
+#include <linux/list.h>
+#include <linux/list_nulls.h>
+#include <linux/atomic.h>
+#include <linux/workqueue.h>
+#include <linux/netfilter/nf_conntrack_tcp.h>
+#ifdef CONFIG_NF_CT_PROTO_SCTP
+#include <linux/netfilter/nf_conntrack_sctp.h>
+#endif
+#include <linux/seqlock.h>
+
+struct ctl_table_header;
+struct nf_conntrack_ecache;
+
+struct nf_generic_net {
+	unsigned int timeout;
+};
+
+struct nf_tcp_net {
+	unsigned int timeouts[TCP_CONNTRACK_TIMEOUT_MAX];
+	u8 tcp_loose;
+	u8 tcp_be_liberal;
+	u8 tcp_max_retrans;
+	u8 tcp_ignore_invalid_rst;
+#if IS_ENABLED(CONFIG_NF_FLOW_TABLE)
+	unsigned int offload_timeout;
+#endif
+};
+
+enum udp_conntrack {
+	UDP_CT_UNREPLIED,
+	UDP_CT_REPLIED,
+	UDP_CT_MAX
+};
+
+struct nf_udp_net {
+	unsigned int timeouts[UDP_CT_MAX];
+#if IS_ENABLED(CONFIG_NF_FLOW_TABLE)
+	unsigned int offload_timeout;
+#endif
+};
+
+struct nf_icmp_net {
+	unsigned int timeout;
+};
+
+#ifdef CONFIG_NF_CT_PROTO_SCTP
+struct nf_sctp_net {
+	unsigned int timeouts[SCTP_CONNTRACK_MAX];
+};
+#endif
+
+#ifdef CONFIG_NF_CT_PROTO_GRE
+enum gre_conntrack {
+	GRE_CT_UNREPLIED,
+	GRE_CT_REPLIED,
+	GRE_CT_MAX
+};
+
+struct nf_gre_net {
+	struct list_head	keymap_list;
+	unsigned int		timeouts[GRE_CT_MAX];
+};
+#endif
+
+struct nf_ip_net {
+	struct nf_generic_net   generic;
+	struct nf_tcp_net	tcp;
+	struct nf_udp_net	udp;
+	struct nf_icmp_net	icmp;
+	struct nf_icmp_net	icmpv6;
+#ifdef CONFIG_NF_CT_PROTO_SCTP
+	struct nf_sctp_net	sctp;
+#endif
+#ifdef CONFIG_NF_CT_PROTO_GRE
+	struct nf_gre_net	gre;
+#endif
+};
+
+struct netns_ct {
+#ifdef CONFIG_NF_CONNTRACK_EVENTS
+	bool ecache_dwork_pending;
+#endif
+	u8			sysctl_log_invalid; /* Log invalid packets */
+	u8			sysctl_events;
+	u8			sysctl_acct;
+	u8			sysctl_tstamp;
+	u8			sysctl_checksum;
+
+	struct ip_conntrack_stat __percpu *stat;
+	struct nf_ct_event_notifier __rcu *nf_conntrack_event_cb;
+	struct nf_ip_net	nf_ct_proto;
+#if defined(CONFIG_NF_CONNTRACK_LABELS)
+	atomic_t		labels_used;
+#endif
+};
+#endif