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Merge branch 'fscrypt' into origin

This commit is contained in:
Theodore Ts'o 2016-11-13 22:02:22 -05:00
parent a2f6d9c4c0 a6e0891286
commit 6da22013bb
7 changed files with 124 additions and 85 deletions
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83
fs/crypto/crypto.c
View File

@ -88,7 +88,7 @@ EXPORT_SYMBOL(fscrypt_release_ctx);
* Return: An allocated and initialized encryption context on success; error
* value or NULL otherwise.
*/
struct fscrypt_ctx *fscrypt_get_ctx(struct inode *inode, gfp_t gfp_flags)
struct fscrypt_ctx *fscrypt_get_ctx(const struct inode *inode, gfp_t gfp_flags)
{
struct fscrypt_ctx *ctx = NULL;
struct fscrypt_info *ci = inode->i_crypt_info;
@ -146,9 +146,10 @@ typedef enum {
FS_ENCRYPT,
} fscrypt_direction_t;
static int do_page_crypto(struct inode *inode,
static int do_page_crypto(const struct inode *inode,
fscrypt_direction_t rw, pgoff_t index,
struct page *src_page, struct page *dest_page,
unsigned int src_len, unsigned int src_offset,
gfp_t gfp_flags)
{
struct {
@ -179,10 +180,10 @@ static int do_page_crypto(struct inode *inode,
memset(xts_tweak.padding, 0, sizeof(xts_tweak.padding));
sg_init_table(&dst, 1);
sg_set_page(&dst, dest_page, PAGE_SIZE, 0);
sg_set_page(&dst, dest_page, src_len, src_offset);
sg_init_table(&src, 1);
sg_set_page(&src, src_page, PAGE_SIZE, 0);
skcipher_request_set_crypt(req, &src, &dst, PAGE_SIZE, &xts_tweak);
sg_set_page(&src, src_page, src_len, src_offset);
skcipher_request_set_crypt(req, &src, &dst, src_len, &xts_tweak);
if (rw == FS_DECRYPT)
res = crypto_skcipher_decrypt(req);
else
@ -213,12 +214,17 @@ static struct page *alloc_bounce_page(struct fscrypt_ctx *ctx, gfp_t gfp_flags)
/**
* fscypt_encrypt_page() - Encrypts a page
* @inode: The inode for which the encryption should take place
* @plaintext_page: The page to encrypt. Must be locked.
* @gfp_flags: The gfp flag for memory allocation
* @inode: The inode for which the encryption should take place
* @plaintext_page: The page to encrypt. Must be locked.
* @plaintext_len: Length of plaintext within page
* @plaintext_offset: Offset of plaintext within page
* @index: Index for encryption. This is mainly the page index, but
* but might be different for multiple calls on same page.
* @gfp_flags: The gfp flag for memory allocation
*
* Allocates a ciphertext page and encrypts plaintext_page into it using the ctx
* encryption context.
* Encrypts plaintext_page using the ctx encryption context. If
* the filesystem supports it, encryption is performed in-place, otherwise a
* new ciphertext_page is allocated and returned.
*
* Called on the page write path. The caller must call
* fscrypt_restore_control_page() on the returned ciphertext page to
@ -227,35 +233,44 @@ static struct page *alloc_bounce_page(struct fscrypt_ctx *ctx, gfp_t gfp_flags)
* Return: An allocated page with the encrypted content on success. Else, an
* error value or NULL.
*/
struct page *fscrypt_encrypt_page(struct inode *inode,
struct page *plaintext_page, gfp_t gfp_flags)
struct page *fscrypt_encrypt_page(const struct inode *inode,
struct page *plaintext_page,
unsigned int plaintext_len,
unsigned int plaintext_offset,
pgoff_t index, gfp_t gfp_flags)
{
struct fscrypt_ctx *ctx;
struct page *ciphertext_page = NULL;
struct page *ciphertext_page = plaintext_page;
int err;
BUG_ON(!PageLocked(plaintext_page));
BUG_ON(plaintext_len % FS_CRYPTO_BLOCK_SIZE != 0);
ctx = fscrypt_get_ctx(inode, gfp_flags);
if (IS_ERR(ctx))
return (struct page *)ctx;
/* The encryption operation will require a bounce page. */
ciphertext_page = alloc_bounce_page(ctx, gfp_flags);
if (IS_ERR(ciphertext_page))
goto errout;
if (!(inode->i_sb->s_cop->flags & FS_CFLG_INPLACE_ENCRYPTION)) {
/* The encryption operation will require a bounce page. */
ciphertext_page = alloc_bounce_page(ctx, gfp_flags);
if (IS_ERR(ciphertext_page))
goto errout;
}
ctx->w.control_page = plaintext_page;
err = do_page_crypto(inode, FS_ENCRYPT, plaintext_page->index,
err = do_page_crypto(inode, FS_ENCRYPT, index,
plaintext_page, ciphertext_page,
plaintext_len, plaintext_offset,
gfp_flags);
if (err) {
ciphertext_page = ERR_PTR(err);
goto errout;
}
SetPagePrivate(ciphertext_page);
set_page_private(ciphertext_page, (unsigned long)ctx);
lock_page(ciphertext_page);
if (!(inode->i_sb->s_cop->flags & FS_CFLG_INPLACE_ENCRYPTION)) {
SetPagePrivate(ciphertext_page);
set_page_private(ciphertext_page, (unsigned long)ctx);
lock_page(ciphertext_page);
}
return ciphertext_page;
errout:
@ -265,8 +280,12 @@ struct page *fscrypt_encrypt_page(struct inode *inode,
EXPORT_SYMBOL(fscrypt_encrypt_page);
/**
* f2crypt_decrypt_page() - Decrypts a page in-place
* @page: The page to decrypt. Must be locked.
* fscrypt_decrypt_page() - Decrypts a page in-place
* @inode: Encrypted inode to decrypt.
* @page: The page to decrypt. Must be locked.
* @len: Number of bytes in @page to be decrypted.
* @offs: Start of data in @page.
* @index: Index for encryption.
*
* Decrypts page in-place using the ctx encryption context.
*
@ -274,16 +293,15 @@ EXPORT_SYMBOL(fscrypt_encrypt_page);
*
* Return: Zero on success, non-zero otherwise.
*/
int fscrypt_decrypt_page(struct page *page)
int fscrypt_decrypt_page(const struct inode *inode, struct page *page,
unsigned int len, unsigned int offs, pgoff_t index)
{
BUG_ON(!PageLocked(page));
return do_page_crypto(page->mapping->host,
FS_DECRYPT, page->index, page, page, GFP_NOFS);
return do_page_crypto(inode, FS_DECRYPT, page->index, page, page, len, offs,
GFP_NOFS);
}
EXPORT_SYMBOL(fscrypt_decrypt_page);
int fscrypt_zeroout_range(struct inode *inode, pgoff_t lblk,
int fscrypt_zeroout_range(const struct inode *inode, pgoff_t lblk,
sector_t pblk, unsigned int len)
{
struct fscrypt_ctx *ctx;
@ -306,7 +324,7 @@ int fscrypt_zeroout_range(struct inode *inode, pgoff_t lblk,
while (len--) {
err = do_page_crypto(inode, FS_ENCRYPT, lblk,
ZERO_PAGE(0), ciphertext_page,
GFP_NOFS);
PAGE_SIZE, 0, GFP_NOFS);
if (err)
goto errout;
@ -414,7 +432,8 @@ static void completion_pages(struct work_struct *work)
bio_for_each_segment_all(bv, bio, i) {
struct page *page = bv->bv_page;
int ret = fscrypt_decrypt_page(page);
int ret = fscrypt_decrypt_page(page->mapping->host, page,
PAGE_SIZE, 0, page->index);
if (ret) {
WARN_ON_ONCE(1);

57
fs/crypto/fname.c
View File

@ -39,65 +39,54 @@ static void fname_crypt_complete(struct crypto_async_request *req, int res)
static int fname_encrypt(struct inode *inode,
const struct qstr *iname, struct fscrypt_str *oname)
{
u32 ciphertext_len;
struct skcipher_request *req = NULL;
DECLARE_FS_COMPLETION_RESULT(ecr);
struct fscrypt_info *ci = inode->i_crypt_info;
struct crypto_skcipher *tfm = ci->ci_ctfm;
int res = 0;
char iv[FS_CRYPTO_BLOCK_SIZE];
struct scatterlist src_sg, dst_sg;
struct scatterlist sg;
int padding = 4 << (ci->ci_flags & FS_POLICY_FLAGS_PAD_MASK);
char *workbuf, buf[32], *alloc_buf = NULL;
unsigned lim;
unsigned int lim;
unsigned int cryptlen;
lim = inode->i_sb->s_cop->max_namelen(inode);
if (iname->len <= 0 || iname->len > lim)
return -EIO;
ciphertext_len = max(iname->len, (u32)FS_CRYPTO_BLOCK_SIZE);
ciphertext_len = round_up(ciphertext_len, padding);
ciphertext_len = min(ciphertext_len, lim);
/*
* Copy the filename to the output buffer for encrypting in-place and
* pad it with the needed number of NUL bytes.
*/
cryptlen = max_t(unsigned int, iname->len, FS_CRYPTO_BLOCK_SIZE);
cryptlen = round_up(cryptlen, padding);
cryptlen = min(cryptlen, lim);
memcpy(oname->name, iname->name, iname->len);
memset(oname->name + iname->len, 0, cryptlen - iname->len);
if (ciphertext_len <= sizeof(buf)) {
workbuf = buf;
} else {
alloc_buf = kmalloc(ciphertext_len, GFP_NOFS);
if (!alloc_buf)
return -ENOMEM;
workbuf = alloc_buf;
}
/* Initialize the IV */
memset(iv, 0, FS_CRYPTO_BLOCK_SIZE);
/* Allocate request */
/* Set up the encryption request */
req = skcipher_request_alloc(tfm, GFP_NOFS);
if (!req) {
printk_ratelimited(KERN_ERR
"%s: crypto_request_alloc() failed\n", __func__);
kfree(alloc_buf);
"%s: skcipher_request_alloc() failed\n", __func__);
return -ENOMEM;
}
skcipher_request_set_callback(req,
CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP,
fname_crypt_complete, &ecr);
sg_init_one(&sg, oname->name, cryptlen);
skcipher_request_set_crypt(req, &sg, &sg, cryptlen, iv);
/* Copy the input */
memcpy(workbuf, iname->name, iname->len);
if (iname->len < ciphertext_len)
memset(workbuf + iname->len, 0, ciphertext_len - iname->len);
/* Initialize IV */
memset(iv, 0, FS_CRYPTO_BLOCK_SIZE);
/* Create encryption request */
sg_init_one(&src_sg, workbuf, ciphertext_len);
sg_init_one(&dst_sg, oname->name, ciphertext_len);
skcipher_request_set_crypt(req, &src_sg, &dst_sg, ciphertext_len, iv);
/* Do the encryption */
res = crypto_skcipher_encrypt(req);
if (res == -EINPROGRESS || res == -EBUSY) {
/* Request is being completed asynchronously; wait for it */
wait_for_completion(&ecr.completion);
res = ecr.res;
}
kfree(alloc_buf);
skcipher_request_free(req);
if (res < 0) {
printk_ratelimited(KERN_ERR
@ -105,7 +94,7 @@ static int fname_encrypt(struct inode *inode,
return res;
}
oname->len = ciphertext_len;
oname->len = cryptlen;
return 0;
}
@ -220,7 +209,7 @@ static int digest_decode(const char *src, int len, char *dst)
return cp - dst;
}
u32 fscrypt_fname_encrypted_size(struct inode *inode, u32 ilen)
u32 fscrypt_fname_encrypted_size(const struct inode *inode, u32 ilen)
{
int padding = 32;
struct fscrypt_info *ci = inode->i_crypt_info;
@ -238,7 +227,7 @@ EXPORT_SYMBOL(fscrypt_fname_encrypted_size);
* Allocates an output buffer that is sufficient for the crypto operation
* specified by the context and the direction.
*/
int fscrypt_fname_alloc_buffer(struct inode *inode,
int fscrypt_fname_alloc_buffer(const struct inode *inode,
u32 ilen, struct fscrypt_str *crypto_str)
{
unsigned int olen = fscrypt_fname_encrypted_size(inode, ilen);

16
fs/crypto/keyinfo.c
View File

@ -185,7 +185,7 @@ int get_crypt_info(struct inode *inode)
struct crypto_skcipher *ctfm;
const char *cipher_str;
int keysize;
u8 raw_key[FS_MAX_KEY_SIZE];
u8 *raw_key = NULL;
int res;
res = fscrypt_initialize();
@ -238,6 +238,15 @@ int get_crypt_info(struct inode *inode)
if (res)
goto out;
/*
* This cannot be a stack buffer because it is passed to the scatterlist
* crypto API as part of key derivation.
*/
res = -ENOMEM;
raw_key = kmalloc(FS_MAX_KEY_SIZE, GFP_NOFS);
if (!raw_key)
goto out;
if (fscrypt_dummy_context_enabled(inode)) {
memset(raw_key, 0x42, FS_AES_256_XTS_KEY_SIZE);
goto got_key;
@ -276,7 +285,8 @@ int get_crypt_info(struct inode *inode)
if (res)
goto out;
memzero_explicit(raw_key, sizeof(raw_key));
kzfree(raw_key);
raw_key = NULL;
if (cmpxchg(&inode->i_crypt_info, NULL, crypt_info) != NULL) {
put_crypt_info(crypt_info);
goto retry;
@ -287,7 +297,7 @@ int get_crypt_info(struct inode *inode)
if (res == -ENOKEY)
res = 0;
put_crypt_info(crypt_info);
memzero_explicit(raw_key, sizeof(raw_key));
kzfree(raw_key);
return res;
}

7
fs/ext4/inode.c
View File

@ -1169,7 +1169,8 @@ static int ext4_block_write_begin(struct page *page, loff_t pos, unsigned len,
if (unlikely(err))
page_zero_new_buffers(page, from, to);
else if (decrypt)
err = fscrypt_decrypt_page(page);
err = fscrypt_decrypt_page(page->mapping->host, page,
PAGE_SIZE, 0, page->index);
return err;
}
#endif
@ -3746,7 +3747,9 @@ static int __ext4_block_zero_page_range(handle_t *handle,
/* We expect the key to be set. */
BUG_ON(!fscrypt_has_encryption_key(inode));
BUG_ON(blocksize != PAGE_SIZE);
WARN_ON_ONCE(fscrypt_decrypt_page(page));
BUG_ON(!PageLocked(page));
WARN_ON_ONCE(fscrypt_decrypt_page(page->mapping->host,
page, PAGE_SIZE, 0, page->index));
}
}
if (ext4_should_journal_data(inode)) {

3
fs/ext4/page-io.c
View File

@ -470,7 +470,8 @@ int ext4_bio_write_page(struct ext4_io_submit *io,
gfp_t gfp_flags = GFP_NOFS;
retry_encrypt:
data_page = fscrypt_encrypt_page(inode, page, gfp_flags);
data_page = fscrypt_encrypt_page(inode, page, PAGE_SIZE, 0,
page->index, gfp_flags);
if (IS_ERR(data_page)) {
ret = PTR_ERR(data_page);
if (ret == -ENOMEM && wbc->sync_mode == WB_SYNC_ALL) {

5
fs/f2fs/data.c
View File

@ -1194,8 +1194,11 @@ int do_write_data_page(struct f2fs_io_info *fio)
f2fs_wait_on_encrypted_page_writeback(F2FS_I_SB(inode),
fio->old_blkaddr);
retry_encrypt:
BUG_ON(!PageLocked(fio->page));
fio->encrypted_page = fscrypt_encrypt_page(inode, fio->page,
gfp_flags);
PAGE_SIZE, 0,
fio->page->index,
gfp_flags);
if (IS_ERR(fio->encrypted_page)) {
err = PTR_ERR(fio->encrypted_page);
if (err == -ENOMEM) {

38
include/linux/fscrypto.h
View File

@ -153,10 +153,16 @@ struct fscrypt_name {
#define fname_name(p) ((p)->disk_name.name)
#define fname_len(p) ((p)->disk_name.len)
/*
* fscrypt superblock flags
*/
#define FS_CFLG_INPLACE_ENCRYPTION (1U << 1)
/*
* crypto opertions for filesystems
*/
struct fscrypt_operations {
unsigned int flags;
int (*get_context)(struct inode *, void *, size_t);
int (*key_prefix)(struct inode *, u8 **);
int (*prepare_context)(struct inode *);
@ -206,7 +212,7 @@ static inline struct page *fscrypt_control_page(struct page *page)
#endif
}
static inline int fscrypt_has_encryption_key(struct inode *inode)
static inline int fscrypt_has_encryption_key(const struct inode *inode)
{
#if IS_ENABLED(CONFIG_FS_ENCRYPTION)
return (inode->i_crypt_info != NULL);
@ -240,14 +246,17 @@ static inline void fscrypt_set_d_op(struct dentry *dentry)
extern struct kmem_cache *fscrypt_info_cachep;
int fscrypt_initialize(void);
extern struct fscrypt_ctx *fscrypt_get_ctx(struct inode *, gfp_t);
extern struct fscrypt_ctx *fscrypt_get_ctx(const struct inode *, gfp_t);
extern void fscrypt_release_ctx(struct fscrypt_ctx *);
extern struct page *fscrypt_encrypt_page(struct inode *, struct page *, gfp_t);
extern int fscrypt_decrypt_page(struct page *);
extern struct page *fscrypt_encrypt_page(const struct inode *, struct page *,
unsigned int, unsigned int,
pgoff_t, gfp_t);
extern int fscrypt_decrypt_page(const struct inode *, struct page *, unsigned int,
unsigned int, pgoff_t);
extern void fscrypt_decrypt_bio_pages(struct fscrypt_ctx *, struct bio *);
extern void fscrypt_pullback_bio_page(struct page **, bool);
extern void fscrypt_restore_control_page(struct page *);
extern int fscrypt_zeroout_range(struct inode *, pgoff_t, sector_t,
extern int fscrypt_zeroout_range(const struct inode *, pgoff_t, sector_t,
unsigned int);
/* policy.c */
extern int fscrypt_process_policy(struct file *, const struct fscrypt_policy *);
@ -264,8 +273,8 @@ extern void fscrypt_put_encryption_info(struct inode *, struct fscrypt_info *);
extern int fscrypt_setup_filename(struct inode *, const struct qstr *,
int lookup, struct fscrypt_name *);
extern void fscrypt_free_filename(struct fscrypt_name *);
extern u32 fscrypt_fname_encrypted_size(struct inode *, u32);
extern int fscrypt_fname_alloc_buffer(struct inode *, u32,
extern u32 fscrypt_fname_encrypted_size(const struct inode *, u32);
extern int fscrypt_fname_alloc_buffer(const struct inode *, u32,
struct fscrypt_str *);
extern void fscrypt_fname_free_buffer(struct fscrypt_str *);
extern int fscrypt_fname_disk_to_usr(struct inode *, u32, u32,
@ -275,7 +284,7 @@ extern int fscrypt_fname_usr_to_disk(struct inode *, const struct qstr *,
#endif
/* crypto.c */
static inline struct fscrypt_ctx *fscrypt_notsupp_get_ctx(struct inode *i,
static inline struct fscrypt_ctx *fscrypt_notsupp_get_ctx(const struct inode *i,
gfp_t f)
{
return ERR_PTR(-EOPNOTSUPP);
@ -286,13 +295,18 @@ static inline void fscrypt_notsupp_release_ctx(struct fscrypt_ctx *c)
return;
}
static inline struct page *fscrypt_notsupp_encrypt_page(struct inode *i,
struct page *p, gfp_t f)
static inline struct page *fscrypt_notsupp_encrypt_page(const struct inode *i,
struct page *p,
unsigned int len,
unsigned int offs,
pgoff_t index, gfp_t f)
{
return ERR_PTR(-EOPNOTSUPP);
}
static inline int fscrypt_notsupp_decrypt_page(struct page *p)
static inline int fscrypt_notsupp_decrypt_page(const struct inode *i, struct page *p,
unsigned int len, unsigned int offs,
pgoff_t index)
{
return -EOPNOTSUPP;
}
@ -313,7 +327,7 @@ static inline void fscrypt_notsupp_restore_control_page(struct page *p)
return;
}
static inline int fscrypt_notsupp_zeroout_range(struct inode *i, pgoff_t p,
static inline int fscrypt_notsupp_zeroout_range(const struct inode *i, pgoff_t p,
sector_t s, unsigned int f)
{
return -EOPNOTSUPP;