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, 89 insertions, 0 deletions

diff --git a/include/net/netns/xfrm.h b/include/net/netns/xfrm.h
new file mode 100644
index 000000000..b73983a17
--- /dev/null
+++ b/include/net/netns/xfrm.h
@@ -0,0 +1,89 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __NETNS_XFRM_H
+#define __NETNS_XFRM_H
+
+#include <linux/list.h>
+#include <linux/wait.h>
+#include <linux/workqueue.h>
+#include <linux/rhashtable-types.h>
+#include <linux/xfrm.h>
+#include <net/dst_ops.h>
+
+struct ctl_table_header;
+
+struct xfrm_policy_hash {
+	struct hlist_head	__rcu *table;
+	unsigned int		hmask;
+	u8			dbits4;
+	u8			sbits4;
+	u8			dbits6;
+	u8			sbits6;
+};
+
+struct xfrm_policy_hthresh {
+	struct work_struct	work;
+	seqlock_t		lock;
+	u8			lbits4;
+	u8			rbits4;
+	u8			lbits6;
+	u8			rbits6;
+};
+
+struct netns_xfrm {
+	struct list_head	state_all;
+	/*
+	 * Hash table to find appropriate SA towards given target (endpoint of
+	 * tunnel or destination of transport mode) allowed by selector.
+	 *
+	 * Main use is finding SA after policy selected tunnel or transport
+	 * mode. Also, it can be used by ah/esp icmp error handler to find
+	 * offending SA.
+	 */
+	struct hlist_head	__rcu *state_bydst;
+	struct hlist_head	__rcu *state_bysrc;
+	struct hlist_head	__rcu *state_byspi;
+	struct hlist_head	__rcu *state_byseq;
+	struct hlist_head	 __percpu *state_cache_input;
+	unsigned int		state_hmask;
+	unsigned int		state_num;
+	struct work_struct	state_hash_work;
+
+	struct list_head	policy_all;
+	struct hlist_head	*policy_byidx;
+	unsigned int		policy_idx_hmask;
+	unsigned int		idx_generator;
+	struct xfrm_policy_hash	policy_bydst[XFRM_POLICY_MAX];
+	unsigned int		policy_count[XFRM_POLICY_MAX * 2];
+	struct work_struct	policy_hash_work;
+	struct xfrm_policy_hthresh policy_hthresh;
+	struct list_head	inexact_bins;
+
+
+	struct sock		__rcu *nlsk;
+	struct sock		*nlsk_stash;
+
+	u32			sysctl_aevent_etime;
+	u32			sysctl_aevent_rseqth;
+	int			sysctl_larval_drop;
+	u32			sysctl_acq_expires;
+
+	u8			policy_default[XFRM_POLICY_MAX];
+
+#ifdef CONFIG_SYSCTL
+	struct ctl_table_header	*sysctl_hdr;
+#endif
+
+	struct dst_ops		xfrm4_dst_ops;
+#if IS_ENABLED(CONFIG_IPV6)
+	struct dst_ops		xfrm6_dst_ops;
+#endif
+	spinlock_t		xfrm_state_lock;
+	seqcount_spinlock_t	xfrm_state_hash_generation;
+	seqcount_spinlock_t	xfrm_policy_hash_generation;
+
+	spinlock_t xfrm_policy_lock;
+	struct mutex xfrm_cfg_mutex;
+	struct delayed_work	nat_keepalive_work;
+};
+
+#endif