From dc50eab76b709d68175a358d6e23a5a3890764d3 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sat, 18 May 2024 19:39:57 +0200 Subject: Merging upstream version 6.7.7. Signed-off-by: Daniel Baumann --- fs/crypto/fscrypt_private.h | 164 +++++++++++++++++++++++++++++--------------- 1 file changed, 109 insertions(+), 55 deletions(-) (limited to 'fs/crypto/fscrypt_private.h') diff --git a/fs/crypto/fscrypt_private.h b/fs/crypto/fscrypt_private.h index 2d63da4863..1892356cf9 100644 --- a/fs/crypto/fscrypt_private.h +++ b/fs/crypto/fscrypt_private.h @@ -47,7 +47,8 @@ struct fscrypt_context_v2 { u8 contents_encryption_mode; u8 filenames_encryption_mode; u8 flags; - u8 __reserved[4]; + u8 log2_data_unit_size; + u8 __reserved[3]; u8 master_key_identifier[FSCRYPT_KEY_IDENTIFIER_SIZE]; u8 nonce[FSCRYPT_FILE_NONCE_SIZE]; }; @@ -165,6 +166,26 @@ fscrypt_policy_flags(const union fscrypt_policy *policy) BUG(); } +static inline int +fscrypt_policy_v2_du_bits(const struct fscrypt_policy_v2 *policy, + const struct inode *inode) +{ + return policy->log2_data_unit_size ?: inode->i_blkbits; +} + +static inline int +fscrypt_policy_du_bits(const union fscrypt_policy *policy, + const struct inode *inode) +{ + switch (policy->version) { + case FSCRYPT_POLICY_V1: + return inode->i_blkbits; + case FSCRYPT_POLICY_V2: + return fscrypt_policy_v2_du_bits(&policy->v2, inode); + } + BUG(); +} + /* * For encrypted symlinks, the ciphertext length is stored at the beginning * of the string in little-endian format. @@ -189,18 +210,18 @@ struct fscrypt_prepared_key { }; /* - * fscrypt_info - the "encryption key" for an inode + * fscrypt_inode_info - the "encryption key" for an inode * * When an encrypted file's key is made available, an instance of this struct is * allocated and stored in ->i_crypt_info. Once created, it remains until the * inode is evicted. */ -struct fscrypt_info { +struct fscrypt_inode_info { /* The key in a form prepared for actual encryption/decryption */ struct fscrypt_prepared_key ci_enc_key; - /* True if ci_enc_key should be freed when this fscrypt_info is freed */ + /* True if ci_enc_key should be freed when this struct is freed */ bool ci_owns_key; #ifdef CONFIG_FS_ENCRYPTION_INLINE_CRYPT @@ -211,6 +232,16 @@ struct fscrypt_info { bool ci_inlinecrypt; #endif + /* + * log2 of the data unit size (granularity of contents encryption) of + * this file. This is computable from ci_policy and ci_inode but is + * cached here for efficiency. Only used for regular files. + */ + u8 ci_data_unit_bits; + + /* Cached value: log2 of number of data units per FS block */ + u8 ci_data_units_per_block_bits; + /* * Encryption mode used for this inode. It corresponds to either the * contents or filenames encryption mode, depending on the inode type. @@ -263,12 +294,13 @@ typedef enum { } fscrypt_direction_t; /* crypto.c */ -extern struct kmem_cache *fscrypt_info_cachep; +extern struct kmem_cache *fscrypt_inode_info_cachep; int fscrypt_initialize(struct super_block *sb); -int fscrypt_crypt_block(const struct inode *inode, fscrypt_direction_t rw, - u64 lblk_num, struct page *src_page, - struct page *dest_page, unsigned int len, - unsigned int offs, gfp_t gfp_flags); +int fscrypt_crypt_data_unit(const struct fscrypt_inode_info *ci, + fscrypt_direction_t rw, u64 index, + struct page *src_page, struct page *dest_page, + unsigned int len, unsigned int offs, + gfp_t gfp_flags); struct page *fscrypt_alloc_bounce_page(gfp_t gfp_flags); void __printf(3, 4) __cold @@ -283,8 +315,8 @@ fscrypt_msg(const struct inode *inode, const char *level, const char *fmt, ...); union fscrypt_iv { struct { - /* logical block number within the file */ - __le64 lblk_num; + /* zero-based index of data unit within the file */ + __le64 index; /* per-file nonce; only set in DIRECT_KEY mode */ u8 nonce[FSCRYPT_FILE_NONCE_SIZE]; @@ -293,8 +325,18 @@ union fscrypt_iv { __le64 dun[FSCRYPT_MAX_IV_SIZE / sizeof(__le64)]; }; -void fscrypt_generate_iv(union fscrypt_iv *iv, u64 lblk_num, - const struct fscrypt_info *ci); +void fscrypt_generate_iv(union fscrypt_iv *iv, u64 index, + const struct fscrypt_inode_info *ci); + +/* + * Return the number of bits used by the maximum file data unit index that is + * possible on the given filesystem, using the given log2 data unit size. + */ +static inline int +fscrypt_max_file_dun_bits(const struct super_block *sb, int du_bits) +{ + return fls64(sb->s_maxbytes - 1) - du_bits; +} /* fname.c */ bool __fscrypt_fname_encrypted_size(const union fscrypt_policy *policy, @@ -332,17 +374,17 @@ void fscrypt_destroy_hkdf(struct fscrypt_hkdf *hkdf); /* inline_crypt.c */ #ifdef CONFIG_FS_ENCRYPTION_INLINE_CRYPT -int fscrypt_select_encryption_impl(struct fscrypt_info *ci); +int fscrypt_select_encryption_impl(struct fscrypt_inode_info *ci); static inline bool -fscrypt_using_inline_encryption(const struct fscrypt_info *ci) +fscrypt_using_inline_encryption(const struct fscrypt_inode_info *ci) { return ci->ci_inlinecrypt; } int fscrypt_prepare_inline_crypt_key(struct fscrypt_prepared_key *prep_key, const u8 *raw_key, - const struct fscrypt_info *ci); + const struct fscrypt_inode_info *ci); void fscrypt_destroy_inline_crypt_key(struct super_block *sb, struct fscrypt_prepared_key *prep_key); @@ -353,7 +395,7 @@ void fscrypt_destroy_inline_crypt_key(struct super_block *sb, */ static inline bool fscrypt_is_key_prepared(struct fscrypt_prepared_key *prep_key, - const struct fscrypt_info *ci) + const struct fscrypt_inode_info *ci) { /* * The two smp_load_acquire()'s here pair with the smp_store_release()'s @@ -370,13 +412,13 @@ fscrypt_is_key_prepared(struct fscrypt_prepared_key *prep_key, #else /* CONFIG_FS_ENCRYPTION_INLINE_CRYPT */ -static inline int fscrypt_select_encryption_impl(struct fscrypt_info *ci) +static inline int fscrypt_select_encryption_impl(struct fscrypt_inode_info *ci) { return 0; } static inline bool -fscrypt_using_inline_encryption(const struct fscrypt_info *ci) +fscrypt_using_inline_encryption(const struct fscrypt_inode_info *ci) { return false; } @@ -384,7 +426,7 @@ fscrypt_using_inline_encryption(const struct fscrypt_info *ci) static inline int fscrypt_prepare_inline_crypt_key(struct fscrypt_prepared_key *prep_key, const u8 *raw_key, - const struct fscrypt_info *ci) + const struct fscrypt_inode_info *ci) { WARN_ON_ONCE(1); return -EOPNOTSUPP; @@ -398,7 +440,7 @@ fscrypt_destroy_inline_crypt_key(struct super_block *sb, static inline bool fscrypt_is_key_prepared(struct fscrypt_prepared_key *prep_key, - const struct fscrypt_info *ci) + const struct fscrypt_inode_info *ci) { return smp_load_acquire(&prep_key->tfm) != NULL; } @@ -433,8 +475,28 @@ struct fscrypt_master_key_secret { * fscrypt_master_key - an in-use master key * * This represents a master encryption key which has been added to the - * filesystem and can be used to "unlock" the encrypted files which were - * encrypted with it. + * filesystem. There are three high-level states that a key can be in: + * + * FSCRYPT_KEY_STATUS_PRESENT + * Key is fully usable; it can be used to unlock inodes that are encrypted + * with it (this includes being able to create new inodes). ->mk_present + * indicates whether the key is in this state. ->mk_secret exists, the key + * is in the keyring, and ->mk_active_refs > 0 due to ->mk_present. + * + * FSCRYPT_KEY_STATUS_INCOMPLETELY_REMOVED + * Removal of this key has been initiated, but some inodes that were + * unlocked with it are still in-use. Like ABSENT, ->mk_secret is wiped, + * and the key can no longer be used to unlock inodes. Unlike ABSENT, the + * key is still in the keyring; ->mk_decrypted_inodes is nonempty; and + * ->mk_active_refs > 0, being equal to the size of ->mk_decrypted_inodes. + * + * This state transitions to ABSENT if ->mk_decrypted_inodes becomes empty, + * or to PRESENT if FS_IOC_ADD_ENCRYPTION_KEY is called again for this key. + * + * FSCRYPT_KEY_STATUS_ABSENT + * Key is fully removed. The key is no longer in the keyring, + * ->mk_decrypted_inodes is empty, ->mk_active_refs == 0, ->mk_secret is + * wiped, and the key can no longer be used to unlock inodes. */ struct fscrypt_master_key { @@ -444,7 +506,7 @@ struct fscrypt_master_key { */ struct hlist_node mk_node; - /* Semaphore that protects ->mk_secret and ->mk_users */ + /* Semaphore that protects ->mk_secret, ->mk_users, and ->mk_present */ struct rw_semaphore mk_sem; /* @@ -454,8 +516,8 @@ struct fscrypt_master_key { * ->mk_direct_keys) that have been prepared continue to exist. * A structural ref only guarantees that the struct continues to exist. * - * There is one active ref associated with ->mk_secret being present, - * and one active ref for each inode in ->mk_decrypted_inodes. + * There is one active ref associated with ->mk_present being true, and + * one active ref for each inode in ->mk_decrypted_inodes. * * There is one structural ref associated with the active refcount being * nonzero. Finding a key in the keyring also takes a structural ref, @@ -467,17 +529,10 @@ struct fscrypt_master_key { struct rcu_head mk_rcu_head; /* - * The secret key material. After FS_IOC_REMOVE_ENCRYPTION_KEY is - * executed, this is wiped and no new inodes can be unlocked with this - * key; however, there may still be inodes in ->mk_decrypted_inodes - * which could not be evicted. As long as some inodes still remain, - * FS_IOC_REMOVE_ENCRYPTION_KEY can be retried, or - * FS_IOC_ADD_ENCRYPTION_KEY can add the secret again. + * The secret key material. Wiped as soon as it is no longer needed; + * for details, see the fscrypt_master_key struct comment. * - * While ->mk_secret is present, one ref in ->mk_active_refs is held. - * - * Locking: protected by ->mk_sem. The manipulation of ->mk_active_refs - * associated with this field is protected by ->mk_sem as well. + * Locking: protected by ->mk_sem. */ struct fscrypt_master_key_secret mk_secret; @@ -500,7 +555,7 @@ struct fscrypt_master_key { * * Locking: protected by ->mk_sem. (We don't just rely on the keyrings * subsystem semaphore ->mk_users->sem, as we need support for atomic - * search+insert along with proper synchronization with ->mk_secret.) + * search+insert along with proper synchronization with other fields.) */ struct key *mk_users; @@ -523,20 +578,17 @@ struct fscrypt_master_key { siphash_key_t mk_ino_hash_key; bool mk_ino_hash_key_initialized; -} __randomize_layout; - -static inline bool -is_master_key_secret_present(const struct fscrypt_master_key_secret *secret) -{ /* - * The READ_ONCE() is only necessary for fscrypt_drop_inode(). - * fscrypt_drop_inode() runs in atomic context, so it can't take the key - * semaphore and thus 'secret' can change concurrently which would be a - * data race. But fscrypt_drop_inode() only need to know whether the - * secret *was* present at the time of check, so READ_ONCE() suffices. + * Whether this key is in the "present" state, i.e. fully usable. For + * details, see the fscrypt_master_key struct comment. + * + * Locking: protected by ->mk_sem, but can be read locklessly using + * READ_ONCE(). Writers must use WRITE_ONCE() when concurrent readers + * are possible. */ - return READ_ONCE(secret->size) != 0; -} + bool mk_present; + +} __randomize_layout; static inline const char *master_key_spec_type( const struct fscrypt_key_specifier *spec) @@ -598,17 +650,18 @@ struct fscrypt_mode { extern struct fscrypt_mode fscrypt_modes[]; int fscrypt_prepare_key(struct fscrypt_prepared_key *prep_key, - const u8 *raw_key, const struct fscrypt_info *ci); + const u8 *raw_key, const struct fscrypt_inode_info *ci); void fscrypt_destroy_prepared_key(struct super_block *sb, struct fscrypt_prepared_key *prep_key); -int fscrypt_set_per_file_enc_key(struct fscrypt_info *ci, const u8 *raw_key); +int fscrypt_set_per_file_enc_key(struct fscrypt_inode_info *ci, + const u8 *raw_key); -int fscrypt_derive_dirhash_key(struct fscrypt_info *ci, +int fscrypt_derive_dirhash_key(struct fscrypt_inode_info *ci, const struct fscrypt_master_key *mk); -void fscrypt_hash_inode_number(struct fscrypt_info *ci, +void fscrypt_hash_inode_number(struct fscrypt_inode_info *ci, const struct fscrypt_master_key *mk); int fscrypt_get_encryption_info(struct inode *inode, bool allow_unsupported); @@ -643,10 +696,11 @@ static inline int fscrypt_require_key(struct inode *inode) void fscrypt_put_direct_key(struct fscrypt_direct_key *dk); -int fscrypt_setup_v1_file_key(struct fscrypt_info *ci, +int fscrypt_setup_v1_file_key(struct fscrypt_inode_info *ci, const u8 *raw_master_key); -int fscrypt_setup_v1_file_key_via_subscribed_keyrings(struct fscrypt_info *ci); +int fscrypt_setup_v1_file_key_via_subscribed_keyrings( + struct fscrypt_inode_info *ci); /* policy.c */ -- cgit v1.2.3