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, 158 insertions, 0 deletions

diff --git a/fs/ntfs/object_id.c b/fs/ntfs/object_id.c
new file mode 100644
index 000000000..89002c375
--- /dev/null
+++ b/fs/ntfs/object_id.c
@@ -0,0 +1,158 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Pocessing of object ids
+ *
+ * Part of this file is based on code from the NTFS-3G.
+ *
+ * Copyright (c) 2009-2019 Jean-Pierre Andre
+ * Copyright (c) 2026 LG Electronics Co., Ltd.
+ */
+
+#include "ntfs.h"
+#include "index.h"
+#include "object_id.h"
+
+struct object_id_index_key {
+	union {
+		u32 alignment;
+		struct guid guid;
+	} object_id;
+} __packed;
+
+struct object_id_index_data {
+	__le64 file_id;
+	struct guid birth_volume_id;
+	struct guid birth_object_id;
+	struct guid domain_id;
+} __packed;
+
+/* Index entry in $Extend/$ObjId */
+struct object_id_index {
+	struct index_entry_header header;
+	struct object_id_index_key key;
+	struct object_id_index_data data;
+} __packed;
+
+__le16 objid_index_name[] = {cpu_to_le16('$'), cpu_to_le16('O'), 0};
+
+/*
+ * open_object_id_index - Open the $Extend/$ObjId file and its index
+ * @vol: NTFS volume structure
+ *
+ * Opens the $ObjId system file and retrieves its index context.
+ *
+ * Return: The index context if opened successfully, or NULL if an error
+ *	   occurred.
+ */
+static struct ntfs_index_context *open_object_id_index(struct ntfs_volume *vol)
+{
+	struct inode *dir_vi, *vi;
+	struct ntfs_inode *dir_ni;
+	struct ntfs_index_context *xo = NULL;
+	struct ntfs_name *name = NULL;
+	u64 mref;
+	int uname_len;
+	__le16 *uname;
+
+	uname_len = ntfs_nlstoucs(vol, "$ObjId", 6, &uname,
+			NTFS_MAX_NAME_LEN);
+	if (uname_len < 0)
+		return NULL;
+
+	/* do not use path_name_to inode - could reopen root */
+	dir_vi = ntfs_iget(vol->sb, FILE_Extend);
+	if (IS_ERR(dir_vi)) {
+		kmem_cache_free(ntfs_name_cache, uname);
+		return NULL;
+	}
+	dir_ni = NTFS_I(dir_vi);
+
+	mutex_lock_nested(&dir_ni->mrec_lock, NTFS_EXTEND_MUTEX_PARENT);
+	mref = ntfs_lookup_inode_by_name(dir_ni, uname, uname_len, &name);
+	mutex_unlock(&dir_ni->mrec_lock);
+	kfree(name);
+	kmem_cache_free(ntfs_name_cache, uname);
+	if (IS_ERR_MREF(mref))
+		goto put_dir_vi;
+
+	vi = ntfs_iget(vol->sb, MREF(mref));
+	if (IS_ERR(vi))
+		goto put_dir_vi;
+
+	xo = ntfs_index_ctx_get(NTFS_I(vi), objid_index_name, 2);
+	if (!xo)
+		iput(vi);
+put_dir_vi:
+	iput(dir_vi);
+	return xo;
+}
+
+
+/*
+ * remove_object_id_index - Remove an object id index entry if attribute present
+ * @ni: NTFS inode structure containing the attribute
+ * @xo:	Index context for the object id index
+ *
+ * Reads the existing object ID attribute and removes it from the index.
+ *
+ * Return: 0 on success, or a negative error code on failure.
+ */
+static int remove_object_id_index(struct ntfs_inode *ni, struct ntfs_index_context *xo)
+{
+	struct object_id_index_key key = {0};
+	s64 size;
+
+	if (ni->data_size == 0)
+		return -ENODATA;
+
+	/* read the existing object id attribute */
+	size = ntfs_inode_attr_pread(VFS_I(ni), 0, sizeof(struct guid),
+				     (char *)&key);
+	if (size != sizeof(struct guid))
+		return -ENODATA;
+
+	if (!ntfs_index_lookup(&key, sizeof(struct object_id_index_key), xo))
+		return ntfs_index_rm(xo);
+
+	return 0;
+}
+
+/*
+ * ntfs_delete_object_id_index - Delete an object_id index entry
+ * @ni:	NTFS inode structure
+ *
+ * Opens the object ID index and removes the entry corresponding to the inode.
+ *
+ * Return: 0 on success, or a negative error code on failure.
+ */
+int ntfs_delete_object_id_index(struct ntfs_inode *ni)
+{
+	struct ntfs_index_context *xo;
+	struct ntfs_inode *xoni;
+	struct inode *attr_vi;
+	int ret = 0;
+
+	attr_vi = ntfs_attr_iget(VFS_I(ni), AT_OBJECT_ID, AT_UNNAMED, 0);
+	if (IS_ERR(attr_vi))
+		return PTR_ERR(attr_vi);
+
+	/*
+	 * read the existing object id and un-index it
+	 */
+	xo = open_object_id_index(ni->vol);
+	if (xo) {
+		xoni = xo->idx_ni;
+		mutex_lock_nested(&xoni->mrec_lock, NTFS_EXTEND_MUTEX_PARENT);
+		ret = remove_object_id_index(NTFS_I(attr_vi), xo);
+		if (!ret) {
+			ntfs_index_entry_mark_dirty(xo);
+			mark_mft_record_dirty(xoni);
+		}
+		ntfs_index_ctx_put(xo);
+		mutex_unlock(&xoni->mrec_lock);
+		iput(VFS_I(xoni));
+	}
+
+	iput(attr_vi);
+	return ret;
+}