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, 272 insertions, 0 deletions

diff --git a/fs/ceph/crypto.h b/fs/ceph/crypto.h
new file mode 100644
index 000000000..79cb563fd
--- /dev/null
+++ b/fs/ceph/crypto.h
@@ -0,0 +1,272 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Ceph fscrypt functionality
+ */
+
+#ifndef _CEPH_CRYPTO_H
+#define _CEPH_CRYPTO_H
+
+#include <crypto/sha2.h>
+#include <linux/fscrypt.h>
+#include <linux/base64.h>
+
+#define CEPH_FSCRYPT_BLOCK_SHIFT   12
+#define CEPH_FSCRYPT_BLOCK_SIZE    (_AC(1, UL) << CEPH_FSCRYPT_BLOCK_SHIFT)
+#define CEPH_FSCRYPT_BLOCK_MASK	   (~(CEPH_FSCRYPT_BLOCK_SIZE-1))
+
+struct ceph_fs_client;
+struct ceph_acl_sec_ctx;
+struct ceph_mds_request;
+
+struct ceph_fname {
+	struct inode	*dir;
+	char		*name;		// b64 encoded, possibly hashed
+	unsigned char	*ctext;		// binary crypttext (if any)
+	u32		name_len;	// length of name buffer
+	u32		ctext_len;	// length of crypttext
+	bool		no_copy;
+};
+
+/*
+ * Header for the encrypted file when truncating the size, this
+ * will be sent to MDS, and the MDS will update the encrypted
+ * last block and then truncate the size.
+ */
+struct ceph_fscrypt_truncate_size_header {
+	__u8  ver;
+	__u8  compat;
+
+	/*
+	 * It will be sizeof(assert_ver + file_offset + block_size)
+	 * if the last block is empty when it's located in a file
+	 * hole. Or the data_len will plus CEPH_FSCRYPT_BLOCK_SIZE.
+	 */
+	__le32 data_len;
+
+	__le64 change_attr;
+	__le64 file_offset;
+	__le32 block_size;
+} __packed;
+
+struct ceph_fscrypt_auth {
+	__le32	cfa_version;
+	__le32	cfa_blob_len;
+	u8	cfa_blob[FSCRYPT_SET_CONTEXT_MAX_SIZE];
+} __packed;
+
+#define CEPH_FSCRYPT_AUTH_VERSION	1
+static inline u32 ceph_fscrypt_auth_len(struct ceph_fscrypt_auth *fa)
+{
+	u32 ctxsize = le32_to_cpu(fa->cfa_blob_len);
+
+	return offsetof(struct ceph_fscrypt_auth, cfa_blob) + ctxsize;
+}
+
+#ifdef CONFIG_FS_ENCRYPTION
+/*
+ * We want to encrypt filenames when creating them, but the encrypted
+ * versions of those names may have illegal characters in them. To mitigate
+ * that, we base64 encode them, but that gives us a result that can exceed
+ * NAME_MAX.
+ *
+ * Follow a similar scheme to fscrypt itself, and cap the filename to a
+ * smaller size. If the ciphertext name is longer than the value below, then
+ * sha256 hash the remaining bytes.
+ *
+ * For the fscrypt_nokey_name struct the dirhash[2] member is useless in ceph
+ * so the corresponding struct will be:
+ *
+ * struct fscrypt_ceph_nokey_name {
+ *	u8 bytes[157];
+ *	u8 sha256[SHA256_DIGEST_SIZE];
+ * }; // 180 bytes => 240 bytes base64-encoded, which is <= NAME_MAX (255)
+ *
+ * (240 bytes is the maximum size allowed for snapshot names to take into
+ *  account the format: '_<SNAPSHOT-NAME>_<INODE-NUMBER>'.)
+ *
+ * Note that for long names that end up having their tail portion hashed, we
+ * must also store the full encrypted name (in the dentry's alternate_name
+ * field).
+ */
+#define CEPH_NOHASH_NAME_MAX (180 - SHA256_DIGEST_SIZE)
+
+void ceph_fscrypt_set_ops(struct super_block *sb);
+
+void ceph_fscrypt_free_dummy_policy(struct ceph_fs_client *fsc);
+
+int ceph_fscrypt_prepare_context(struct inode *dir, struct inode *inode,
+				 struct ceph_acl_sec_ctx *as);
+void ceph_fscrypt_as_ctx_to_req(struct ceph_mds_request *req,
+				struct ceph_acl_sec_ctx *as);
+int ceph_encode_encrypted_dname(struct inode *parent, char *buf, int len);
+
+static inline int ceph_fname_alloc_buffer(struct inode *parent,
+					  struct fscrypt_str *fname)
+{
+	if (!IS_ENCRYPTED(parent))
+		return 0;
+	return fscrypt_fname_alloc_buffer(NAME_MAX, fname);
+}
+
+static inline void ceph_fname_free_buffer(struct inode *parent,
+					  struct fscrypt_str *fname)
+{
+	if (IS_ENCRYPTED(parent))
+		fscrypt_fname_free_buffer(fname);
+}
+
+int ceph_fname_to_usr(const struct ceph_fname *fname, unsigned char *tname,
+		      struct fscrypt_str *oname, bool *is_nokey);
+int ceph_fscrypt_prepare_readdir(struct inode *dir);
+
+static inline unsigned int ceph_fscrypt_blocks(u64 off, u64 len)
+{
+	/* crypto blocks cannot span more than one page */
+	BUILD_BUG_ON(CEPH_FSCRYPT_BLOCK_SHIFT > PAGE_SHIFT);
+
+	return ((off+len+CEPH_FSCRYPT_BLOCK_SIZE-1) >> CEPH_FSCRYPT_BLOCK_SHIFT) -
+		(off >> CEPH_FSCRYPT_BLOCK_SHIFT);
+}
+
+/*
+ * If we have an encrypted inode then we must adjust the offset and
+ * range of the on-the-wire read to cover an entire encryption block.
+ * The copy will be done using the original offset and length, after
+ * we've decrypted the result.
+ */
+static inline void ceph_fscrypt_adjust_off_and_len(struct inode *inode,
+						   u64 *off, u64 *len)
+{
+	if (IS_ENCRYPTED(inode)) {
+		*len = ceph_fscrypt_blocks(*off, *len) * CEPH_FSCRYPT_BLOCK_SIZE;
+		*off &= CEPH_FSCRYPT_BLOCK_MASK;
+	}
+}
+
+int ceph_fscrypt_decrypt_block_inplace(const struct inode *inode,
+				  struct page *page, unsigned int len,
+				  unsigned int offs, u64 lblk_num);
+int ceph_fscrypt_encrypt_block_inplace(const struct inode *inode,
+				  struct page *page, unsigned int len,
+				  unsigned int offs, u64 lblk_num);
+int ceph_fscrypt_decrypt_pages(struct inode *inode, struct page **page,
+			       u64 off, int len);
+int ceph_fscrypt_decrypt_extents(struct inode *inode, struct page **page,
+				 u64 off, struct ceph_sparse_extent *map,
+				 u32 ext_cnt);
+int ceph_fscrypt_encrypt_pages(struct inode *inode, struct page **page, u64 off,
+			       int len);
+
+static inline struct page *ceph_fscrypt_pagecache_page(struct page *page)
+{
+	return fscrypt_is_bounce_page(page) ? fscrypt_pagecache_page(page) : page;
+}
+
+#else /* CONFIG_FS_ENCRYPTION */
+
+static inline void ceph_fscrypt_set_ops(struct super_block *sb)
+{
+}
+
+static inline void ceph_fscrypt_free_dummy_policy(struct ceph_fs_client *fsc)
+{
+}
+
+static inline int ceph_fscrypt_prepare_context(struct inode *dir,
+					       struct inode *inode,
+					       struct ceph_acl_sec_ctx *as)
+{
+	if (IS_ENCRYPTED(dir))
+		return -EOPNOTSUPP;
+	return 0;
+}
+
+static inline void ceph_fscrypt_as_ctx_to_req(struct ceph_mds_request *req,
+						struct ceph_acl_sec_ctx *as_ctx)
+{
+}
+
+static inline int ceph_encode_encrypted_dname(struct inode *parent, char *buf,
+					      int len)
+{
+	return len;
+}
+
+static inline int ceph_fname_alloc_buffer(struct inode *parent,
+					  struct fscrypt_str *fname)
+{
+	return 0;
+}
+
+static inline void ceph_fname_free_buffer(struct inode *parent,
+					  struct fscrypt_str *fname)
+{
+}
+
+static inline int ceph_fname_to_usr(const struct ceph_fname *fname,
+				    unsigned char *tname,
+				    struct fscrypt_str *oname, bool *is_nokey)
+{
+	oname->name = fname->name;
+	oname->len = fname->name_len;
+	return 0;
+}
+
+static inline int ceph_fscrypt_prepare_readdir(struct inode *dir)
+{
+	return 0;
+}
+
+static inline void ceph_fscrypt_adjust_off_and_len(struct inode *inode,
+						   u64 *off, u64 *len)
+{
+}
+
+static inline int ceph_fscrypt_decrypt_block_inplace(const struct inode *inode,
+					  struct page *page, unsigned int len,
+					  unsigned int offs, u64 lblk_num)
+{
+	return 0;
+}
+
+static inline int ceph_fscrypt_encrypt_block_inplace(const struct inode *inode,
+					  struct page *page, unsigned int len,
+					  unsigned int offs, u64 lblk_num)
+{
+	return 0;
+}
+
+static inline int ceph_fscrypt_decrypt_pages(struct inode *inode,
+					     struct page **page, u64 off,
+					     int len)
+{
+	return 0;
+}
+
+static inline int ceph_fscrypt_decrypt_extents(struct inode *inode,
+					       struct page **page, u64 off,
+					       struct ceph_sparse_extent *map,
+					       u32 ext_cnt)
+{
+	return 0;
+}
+
+static inline int ceph_fscrypt_encrypt_pages(struct inode *inode,
+					     struct page **page, u64 off,
+					     int len)
+{
+	return 0;
+}
+
+static inline struct page *ceph_fscrypt_pagecache_page(struct page *page)
+{
+	return page;
+}
+#endif /* CONFIG_FS_ENCRYPTION */
+
+static inline loff_t ceph_fscrypt_page_offset(struct page *page)
+{
+	return page_offset(ceph_fscrypt_pagecache_page(page));
+}
+
+#endif /* _CEPH_CRYPTO_H */