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, 175 insertions, 0 deletions

diff --git a/net/mac80211/key.h b/net/mac80211/key.h
new file mode 100644
index 000000000..826e4e938
--- /dev/null
+++ b/net/mac80211/key.h
@@ -0,0 +1,175 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright 2002-2004, Instant802 Networks, Inc.
+ * Copyright 2005, Devicescape Software, Inc.
+ * Copyright (C) 2019, 2022-2023 Intel Corporation
+ */
+
+#ifndef IEEE80211_KEY_H
+#define IEEE80211_KEY_H
+
+#include <linux/types.h>
+#include <linux/list.h>
+#include <linux/crypto.h>
+#include <linux/rcupdate.h>
+#include <crypto/aes-cbc-macs.h>
+#include <crypto/arc4.h>
+#include <net/mac80211.h>
+
+#define NUM_DEFAULT_KEYS 4
+#define NUM_DEFAULT_MGMT_KEYS 2
+#define NUM_DEFAULT_BEACON_KEYS 2
+#define INVALID_PTK_KEYIDX 2 /* Keyidx always pointing to a NULL key for PTK */
+
+struct ieee80211_local;
+struct ieee80211_sub_if_data;
+struct ieee80211_link_data;
+struct sta_info;
+
+/**
+ * enum ieee80211_internal_key_flags - internal key flags
+ *
+ * @KEY_FLAG_UPLOADED_TO_HARDWARE: Indicates that this key is present
+ *	in the hardware for TX crypto hardware acceleration.
+ * @KEY_FLAG_TAINTED: Key is tainted and packets should be dropped.
+ */
+enum ieee80211_internal_key_flags {
+	KEY_FLAG_UPLOADED_TO_HARDWARE	= BIT(0),
+	KEY_FLAG_TAINTED		= BIT(1),
+};
+
+enum ieee80211_internal_tkip_state {
+	TKIP_STATE_NOT_INIT,
+	TKIP_STATE_PHASE1_DONE,
+	TKIP_STATE_PHASE1_HW_UPLOADED,
+};
+
+struct tkip_ctx {
+	u16 p1k[5];	/* p1k cache */
+	u32 p1k_iv32;	/* iv32 for which p1k computed */
+	enum ieee80211_internal_tkip_state state;
+};
+
+struct tkip_ctx_rx {
+	struct tkip_ctx ctx;
+	u32 iv32;	/* current iv32 */
+	u16 iv16;	/* current iv16 */
+};
+
+struct ieee80211_key {
+	struct ieee80211_local *local;
+	struct ieee80211_sub_if_data *sdata;
+	struct sta_info *sta;
+
+	/* for sdata list */
+	struct list_head list;
+
+	/* protected by key mutex */
+	unsigned int flags;
+
+	union {
+		struct {
+			/* protects tx context */
+			spinlock_t txlock;
+
+			/* last used TSC */
+			struct tkip_ctx tx;
+
+			/* last received RSC */
+			struct tkip_ctx_rx rx[IEEE80211_NUM_TIDS];
+
+			/* number of mic failures */
+			u32 mic_failures;
+		} tkip;
+		struct {
+			/*
+			 * Last received packet number. The first
+			 * IEEE80211_NUM_TIDS counters are used with Data
+			 * frames and the last counter is used with Robust
+			 * Management frames.
+			 */
+			u8 rx_pn[IEEE80211_NUM_TIDS + 1][IEEE80211_CCMP_PN_LEN];
+			struct crypto_aead *tfm;
+			u32 replays; /* dot11RSNAStatsCCMPReplays */
+		} ccmp;
+		struct {
+			u8 rx_pn[IEEE80211_CMAC_PN_LEN];
+			struct aes_cmac_key key;
+			u32 replays; /* dot11RSNAStatsCMACReplays */
+			u32 icverrors; /* dot11RSNAStatsCMACICVErrors */
+		} aes_cmac;
+		struct {
+			u8 rx_pn[IEEE80211_GMAC_PN_LEN];
+			struct crypto_aead *tfm;
+			u32 replays; /* dot11RSNAStatsCMACReplays */
+			u32 icverrors; /* dot11RSNAStatsCMACICVErrors */
+		} aes_gmac;
+		struct {
+			/* Last received packet number. The first
+			 * IEEE80211_NUM_TIDS counters are used with Data
+			 * frames and the last counter is used with Robust
+			 * Management frames.
+			 */
+			u8 rx_pn[IEEE80211_NUM_TIDS + 1][IEEE80211_GCMP_PN_LEN];
+			struct crypto_aead *tfm;
+			u32 replays; /* dot11RSNAStatsGCMPReplays */
+		} gcmp;
+		struct {
+			/* generic cipher scheme */
+			u8 rx_pn[IEEE80211_NUM_TIDS + 1][IEEE80211_MAX_PN_LEN];
+		} gen;
+	} u;
+
+#ifdef CONFIG_MAC80211_DEBUGFS
+	struct {
+		struct dentry *stalink;
+		struct dentry *dir;
+		int cnt;
+	} debugfs;
+#endif
+
+	unsigned int color;
+
+	/*
+	 * key config, must be last because it contains key
+	 * material as variable length member
+	 */
+	struct ieee80211_key_conf conf;
+};
+
+struct ieee80211_key *
+ieee80211_key_alloc(u32 cipher, int idx, size_t key_len,
+		    const u8 *key_data,
+		    size_t seq_len, const u8 *seq);
+/*
+ * Insert a key into data structures (sdata, sta if necessary)
+ * to make it used, free old key. On failure, also free the new key.
+ */
+int ieee80211_key_link(struct ieee80211_key *key,
+		       struct ieee80211_link_data *link,
+		       struct sta_info *sta);
+int ieee80211_set_tx_key(struct ieee80211_key *key);
+void ieee80211_key_free(struct ieee80211_key *key, bool delay_tailroom);
+void ieee80211_key_free_unused(struct ieee80211_key *key);
+void ieee80211_set_default_key(struct ieee80211_link_data *link, int idx,
+			       bool uni, bool multi);
+void ieee80211_set_default_mgmt_key(struct ieee80211_link_data *link,
+				    int idx);
+void ieee80211_set_default_beacon_key(struct ieee80211_link_data *link,
+				      int idx);
+void ieee80211_remove_link_keys(struct ieee80211_link_data *link,
+				struct list_head *keys);
+void ieee80211_free_key_list(struct ieee80211_local *local,
+			     struct list_head *keys);
+void ieee80211_free_keys(struct ieee80211_sub_if_data *sdata,
+			 bool force_synchronize);
+void ieee80211_free_sta_keys(struct ieee80211_local *local,
+			     struct sta_info *sta);
+void ieee80211_reenable_keys(struct ieee80211_sub_if_data *sdata);
+int ieee80211_key_switch_links(struct ieee80211_sub_if_data *sdata,
+			       unsigned long del_links_mask,
+			       unsigned long add_links_mask);
+void ieee80211_delayed_tailroom_dec(struct wiphy *wiphy,
+				    struct wiphy_work *wk);
+
+#endif /* IEEE80211_KEY_H */