Commit 6c24337f authored by Linus Torvalds's avatar Linus Torvalds

Merge tag 'fscrypt-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/fscrypt

Pull fscrypt updates from Ted Ts'o:
 "Various cleanups for the file system encryption feature"

* tag 'fscrypt-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/fscrypt:
  fscrypt: constify struct fscrypt_operations
  fscrypt: properly declare on-stack completion
  fscrypt: split supp and notsupp declarations into their own headers
  fscrypt: remove redundant assignment of res
  fscrypt: make fscrypt_operations.key_prefix a string
  fscrypt: remove unused 'mode' member of fscrypt_ctx
  ext4: don't allow encrypted operations without keys
  fscrypt: make test_dummy_encryption require a keyring key
  fscrypt: factor out bio specific functions
  fscrypt: pass up error codes from ->get_context()
  fscrypt: remove user-triggerable warning messages
  fscrypt: use EEXIST when file already uses different policy
  fscrypt: use ENOTDIR when setting encryption policy on nondirectory
  fscrypt: use ENOKEY when file cannot be created w/o key
parents 786856b6 6f69f0ed
......@@ -5281,7 +5281,7 @@ M: Jaegeuk Kim <jaegeuk@kernel.org>
L: linux-fsdevel@vger.kernel.org
S: Supported
F: fs/crypto/
F: include/linux/fscrypto.h
F: include/linux/fscrypt*.h
F2FS FILE SYSTEM
M: Jaegeuk Kim <jaegeuk@kernel.org>
......
config FS_ENCRYPTION
tristate "FS Encryption (Per-file encryption)"
depends on BLOCK
select CRYPTO
select CRYPTO_AES
select CRYPTO_CBC
......
obj-$(CONFIG_FS_ENCRYPTION) += fscrypto.o
fscrypto-y := crypto.o fname.o policy.o keyinfo.o
fscrypto-$(CONFIG_BLOCK) += bio.o
/*
* This contains encryption functions for per-file encryption.
*
* Copyright (C) 2015, Google, Inc.
* Copyright (C) 2015, Motorola Mobility
*
* Written by Michael Halcrow, 2014.
*
* Filename encryption additions
* Uday Savagaonkar, 2014
* Encryption policy handling additions
* Ildar Muslukhov, 2014
* Add fscrypt_pullback_bio_page()
* Jaegeuk Kim, 2015.
*
* This has not yet undergone a rigorous security audit.
*
* The usage of AES-XTS should conform to recommendations in NIST
* Special Publication 800-38E and IEEE P1619/D16.
*/
#include <linux/pagemap.h>
#include <linux/module.h>
#include <linux/bio.h>
#include <linux/namei.h>
#include "fscrypt_private.h"
/*
* Call fscrypt_decrypt_page on every single page, reusing the encryption
* context.
*/
static void completion_pages(struct work_struct *work)
{
struct fscrypt_ctx *ctx =
container_of(work, struct fscrypt_ctx, r.work);
struct bio *bio = ctx->r.bio;
struct bio_vec *bv;
int i;
bio_for_each_segment_all(bv, bio, i) {
struct page *page = bv->bv_page;
int ret = fscrypt_decrypt_page(page->mapping->host, page,
PAGE_SIZE, 0, page->index);
if (ret) {
WARN_ON_ONCE(1);
SetPageError(page);
} else {
SetPageUptodate(page);
}
unlock_page(page);
}
fscrypt_release_ctx(ctx);
bio_put(bio);
}
void fscrypt_decrypt_bio_pages(struct fscrypt_ctx *ctx, struct bio *bio)
{
INIT_WORK(&ctx->r.work, completion_pages);
ctx->r.bio = bio;
queue_work(fscrypt_read_workqueue, &ctx->r.work);
}
EXPORT_SYMBOL(fscrypt_decrypt_bio_pages);
void fscrypt_pullback_bio_page(struct page **page, bool restore)
{
struct fscrypt_ctx *ctx;
struct page *bounce_page;
/* The bounce data pages are unmapped. */
if ((*page)->mapping)
return;
/* The bounce data page is unmapped. */
bounce_page = *page;
ctx = (struct fscrypt_ctx *)page_private(bounce_page);
/* restore control page */
*page = ctx->w.control_page;
if (restore)
fscrypt_restore_control_page(bounce_page);
}
EXPORT_SYMBOL(fscrypt_pullback_bio_page);
int fscrypt_zeroout_range(const struct inode *inode, pgoff_t lblk,
sector_t pblk, unsigned int len)
{
struct fscrypt_ctx *ctx;
struct page *ciphertext_page = NULL;
struct bio *bio;
int ret, err = 0;
BUG_ON(inode->i_sb->s_blocksize != PAGE_SIZE);
ctx = fscrypt_get_ctx(inode, GFP_NOFS);
if (IS_ERR(ctx))
return PTR_ERR(ctx);
ciphertext_page = fscrypt_alloc_bounce_page(ctx, GFP_NOWAIT);
if (IS_ERR(ciphertext_page)) {
err = PTR_ERR(ciphertext_page);
goto errout;
}
while (len--) {
err = fscrypt_do_page_crypto(inode, FS_ENCRYPT, lblk,
ZERO_PAGE(0), ciphertext_page,
PAGE_SIZE, 0, GFP_NOFS);
if (err)
goto errout;
bio = bio_alloc(GFP_NOWAIT, 1);
if (!bio) {
err = -ENOMEM;
goto errout;
}
bio->bi_bdev = inode->i_sb->s_bdev;
bio->bi_iter.bi_sector =
pblk << (inode->i_sb->s_blocksize_bits - 9);
bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
ret = bio_add_page(bio, ciphertext_page,
inode->i_sb->s_blocksize, 0);
if (ret != inode->i_sb->s_blocksize) {
/* should never happen! */
WARN_ON(1);
bio_put(bio);
err = -EIO;
goto errout;
}
err = submit_bio_wait(bio);
if ((err == 0) && bio->bi_error)
err = -EIO;
bio_put(bio);
if (err)
goto errout;
lblk++;
pblk++;
}
err = 0;
errout:
fscrypt_release_ctx(ctx);
return err;
}
EXPORT_SYMBOL(fscrypt_zeroout_range);
......@@ -24,7 +24,6 @@
#include <linux/module.h>
#include <linux/scatterlist.h>
#include <linux/ratelimit.h>
#include <linux/bio.h>
#include <linux/dcache.h>
#include <linux/namei.h>
#include "fscrypt_private.h"
......@@ -44,7 +43,7 @@ static mempool_t *fscrypt_bounce_page_pool = NULL;
static LIST_HEAD(fscrypt_free_ctxs);
static DEFINE_SPINLOCK(fscrypt_ctx_lock);
static struct workqueue_struct *fscrypt_read_workqueue;
struct workqueue_struct *fscrypt_read_workqueue;
static DEFINE_MUTEX(fscrypt_init_mutex);
static struct kmem_cache *fscrypt_ctx_cachep;
......@@ -141,16 +140,10 @@ static void page_crypt_complete(struct crypto_async_request *req, int res)
complete(&ecr->completion);
}
typedef enum {
FS_DECRYPT = 0,
FS_ENCRYPT,
} fscrypt_direction_t;
static int do_page_crypto(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_do_page_crypto(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)
{
struct {
__le64 index;
......@@ -205,7 +198,8 @@ static int do_page_crypto(const struct inode *inode,
return 0;
}
static struct page *alloc_bounce_page(struct fscrypt_ctx *ctx, gfp_t gfp_flags)
struct page *fscrypt_alloc_bounce_page(struct fscrypt_ctx *ctx,
gfp_t gfp_flags)
{
ctx->w.bounce_page = mempool_alloc(fscrypt_bounce_page_pool, gfp_flags);
if (ctx->w.bounce_page == NULL)
......@@ -260,9 +254,9 @@ struct page *fscrypt_encrypt_page(const struct inode *inode,
if (inode->i_sb->s_cop->flags & FS_CFLG_OWN_PAGES) {
/* with inplace-encryption we just encrypt the page */
err = do_page_crypto(inode, FS_ENCRYPT, lblk_num,
page, ciphertext_page,
len, offs, gfp_flags);
err = fscrypt_do_page_crypto(inode, FS_ENCRYPT, lblk_num, page,
ciphertext_page, len, offs,
gfp_flags);
if (err)
return ERR_PTR(err);
......@@ -276,14 +270,14 @@ struct page *fscrypt_encrypt_page(const struct inode *inode,
return (struct page *)ctx;
/* The encryption operation will require a bounce page. */
ciphertext_page = alloc_bounce_page(ctx, gfp_flags);
ciphertext_page = fscrypt_alloc_bounce_page(ctx, gfp_flags);
if (IS_ERR(ciphertext_page))
goto errout;
ctx->w.control_page = page;
err = do_page_crypto(inode, FS_ENCRYPT, lblk_num,
page, ciphertext_page,
len, offs, gfp_flags);
err = fscrypt_do_page_crypto(inode, FS_ENCRYPT, lblk_num,
page, ciphertext_page, len, offs,
gfp_flags);
if (err) {
ciphertext_page = ERR_PTR(err);
goto errout;
......@@ -320,72 +314,11 @@ int fscrypt_decrypt_page(const struct inode *inode, struct page *page,
if (!(inode->i_sb->s_cop->flags & FS_CFLG_OWN_PAGES))
BUG_ON(!PageLocked(page));
return do_page_crypto(inode, FS_DECRYPT, lblk_num, page, page, len,
offs, GFP_NOFS);
return fscrypt_do_page_crypto(inode, FS_DECRYPT, lblk_num, page, page,
len, offs, GFP_NOFS);
}
EXPORT_SYMBOL(fscrypt_decrypt_page);
int fscrypt_zeroout_range(const struct inode *inode, pgoff_t lblk,
sector_t pblk, unsigned int len)
{
struct fscrypt_ctx *ctx;
struct page *ciphertext_page = NULL;
struct bio *bio;
int ret, err = 0;
BUG_ON(inode->i_sb->s_blocksize != PAGE_SIZE);
ctx = fscrypt_get_ctx(inode, GFP_NOFS);
if (IS_ERR(ctx))
return PTR_ERR(ctx);
ciphertext_page = alloc_bounce_page(ctx, GFP_NOWAIT);
if (IS_ERR(ciphertext_page)) {
err = PTR_ERR(ciphertext_page);
goto errout;
}
while (len--) {
err = do_page_crypto(inode, FS_ENCRYPT, lblk,
ZERO_PAGE(0), ciphertext_page,
PAGE_SIZE, 0, GFP_NOFS);
if (err)
goto errout;
bio = bio_alloc(GFP_NOWAIT, 1);
if (!bio) {
err = -ENOMEM;
goto errout;
}
bio->bi_bdev = inode->i_sb->s_bdev;
bio->bi_iter.bi_sector =
pblk << (inode->i_sb->s_blocksize_bits - 9);
bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
ret = bio_add_page(bio, ciphertext_page,
inode->i_sb->s_blocksize, 0);
if (ret != inode->i_sb->s_blocksize) {
/* should never happen! */
WARN_ON(1);
bio_put(bio);
err = -EIO;
goto errout;
}
err = submit_bio_wait(bio);
if ((err == 0) && bio->bi_error)
err = -EIO;
bio_put(bio);
if (err)
goto errout;
lblk++;
pblk++;
}
err = 0;
errout:
fscrypt_release_ctx(ctx);
return err;
}
EXPORT_SYMBOL(fscrypt_zeroout_range);
/*
* Validate dentries for encrypted directories to make sure we aren't
* potentially caching stale data after a key has been added or
......@@ -442,64 +375,6 @@ const struct dentry_operations fscrypt_d_ops = {
};
EXPORT_SYMBOL(fscrypt_d_ops);
/*
* Call fscrypt_decrypt_page on every single page, reusing the encryption
* context.
*/
static void completion_pages(struct work_struct *work)
{
struct fscrypt_ctx *ctx =
container_of(work, struct fscrypt_ctx, r.work);
struct bio *bio = ctx->r.bio;
struct bio_vec *bv;
int i;
bio_for_each_segment_all(bv, bio, i) {
struct page *page = bv->bv_page;
int ret = fscrypt_decrypt_page(page->mapping->host, page,
PAGE_SIZE, 0, page->index);
if (ret) {
WARN_ON_ONCE(1);
SetPageError(page);
} else {
SetPageUptodate(page);
}
unlock_page(page);
}
fscrypt_release_ctx(ctx);
bio_put(bio);
}
void fscrypt_decrypt_bio_pages(struct fscrypt_ctx *ctx, struct bio *bio)
{
INIT_WORK(&ctx->r.work, completion_pages);
ctx->r.bio = bio;
queue_work(fscrypt_read_workqueue, &ctx->r.work);
}
EXPORT_SYMBOL(fscrypt_decrypt_bio_pages);
void fscrypt_pullback_bio_page(struct page **page, bool restore)
{
struct fscrypt_ctx *ctx;
struct page *bounce_page;
/* The bounce data pages are unmapped. */
if ((*page)->mapping)
return;
/* The bounce data page is unmapped. */
bounce_page = *page;
ctx = (struct fscrypt_ctx *)page_private(bounce_page);
/* restore control page */
*page = ctx->w.control_page;
if (restore)
fscrypt_restore_control_page(bounce_page);
}
EXPORT_SYMBOL(fscrypt_pullback_bio_page);
void fscrypt_restore_control_page(struct page *page)
{
struct fscrypt_ctx *ctx;
......
......@@ -332,7 +332,7 @@ int fscrypt_fname_usr_to_disk(struct inode *inode,
* in a directory. Consequently, a user space name cannot be mapped to
* a disk-space name
*/
return -EACCES;
return -ENOKEY;
}
EXPORT_SYMBOL(fscrypt_fname_usr_to_disk);
......@@ -367,7 +367,7 @@ int fscrypt_setup_filename(struct inode *dir, const struct qstr *iname,
return 0;
}
if (!lookup)
return -EACCES;
return -ENOKEY;
/*
* We don't have the key and we are doing a lookup; decode the
......
......@@ -11,7 +11,7 @@
#ifndef _FSCRYPT_PRIVATE_H
#define _FSCRYPT_PRIVATE_H
#include <linux/fscrypto.h>
#include <linux/fscrypt_supp.h>
#define FS_FNAME_CRYPTO_DIGEST_SIZE 32
......@@ -71,6 +71,11 @@ struct fscrypt_info {
u8 ci_master_key[FS_KEY_DESCRIPTOR_SIZE];
};
typedef enum {
FS_DECRYPT = 0,
FS_ENCRYPT,
} fscrypt_direction_t;
#define FS_CTX_REQUIRES_FREE_ENCRYPT_FL 0x00000001
#define FS_CTX_HAS_BOUNCE_BUFFER_FL 0x00000002
......@@ -81,11 +86,20 @@ struct fscrypt_completion_result {
#define DECLARE_FS_COMPLETION_RESULT(ecr) \
struct fscrypt_completion_result ecr = { \
COMPLETION_INITIALIZER((ecr).completion), 0 }
COMPLETION_INITIALIZER_ONSTACK((ecr).completion), 0 }
/* crypto.c */
int fscrypt_initialize(unsigned int cop_flags);
extern int fscrypt_initialize(unsigned int cop_flags);
extern struct workqueue_struct *fscrypt_read_workqueue;
extern int fscrypt_do_page_crypto(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);
extern struct page *fscrypt_alloc_bounce_page(struct fscrypt_ctx *ctx,
gfp_t gfp_flags);
/* keyinfo.c */
extern int fscrypt_get_crypt_info(struct inode *);
......
......@@ -77,26 +77,22 @@ static int derive_key_aes(u8 deriving_key[FS_AES_128_ECB_KEY_SIZE],
static int validate_user_key(struct fscrypt_info *crypt_info,
struct fscrypt_context *ctx, u8 *raw_key,
u8 *prefix, int prefix_size)
const char *prefix)
{
u8 *full_key_descriptor;
char *description;
struct key *keyring_key;
struct fscrypt_key *master_key;
const struct user_key_payload *ukp;
int full_key_len = prefix_size + (FS_KEY_DESCRIPTOR_SIZE * 2) + 1;
int res;
full_key_descriptor = kmalloc(full_key_len, GFP_NOFS);
if (!full_key_descriptor)
description = kasprintf(GFP_NOFS, "%s%*phN", prefix,
FS_KEY_DESCRIPTOR_SIZE,
ctx->master_key_descriptor);
if (!description)
return -ENOMEM;
memcpy(full_key_descriptor, prefix, prefix_size);
sprintf(full_key_descriptor + prefix_size,
"%*phN", FS_KEY_DESCRIPTOR_SIZE,
ctx->master_key_descriptor);
full_key_descriptor[full_key_len - 1] = '\0';
keyring_key = request_key(&key_type_logon, full_key_descriptor, NULL);
kfree(full_key_descriptor);
keyring_key = request_key(&key_type_logon, description, NULL);
kfree(description);
if (IS_ERR(keyring_key))
return PTR_ERR(keyring_key);
......@@ -206,12 +202,15 @@ int fscrypt_get_crypt_info(struct inode *inode)
res = inode->i_sb->s_cop->get_context(inode, &ctx, sizeof(ctx));
if (res < 0) {
if (!fscrypt_dummy_context_enabled(inode))
if (!fscrypt_dummy_context_enabled(inode) ||
inode->i_sb->s_cop->is_encrypted(inode))
return res;
/* Fake up a context for an unencrypted directory */
memset(&ctx, 0, sizeof(ctx));
ctx.format = FS_ENCRYPTION_CONTEXT_FORMAT_V1;
ctx.contents_encryption_mode = FS_ENCRYPTION_MODE_AES_256_XTS;
ctx.filenames_encryption_mode = FS_ENCRYPTION_MODE_AES_256_CTS;
ctx.flags = 0;
memset(ctx.master_key_descriptor, 0x42, FS_KEY_DESCRIPTOR_SIZE);
} else if (res != sizeof(ctx)) {
return -EINVAL;
}
......@@ -247,21 +246,10 @@ int fscrypt_get_crypt_info(struct inode *inode)
if (!raw_key)
goto out;
if (fscrypt_dummy_context_enabled(inode)) {
memset(raw_key, 0x42, keysize/2);
memset(raw_key+keysize/2, 0x24, keysize - (keysize/2));
goto got_key;
}
res = validate_user_key(crypt_info, &ctx, raw_key,
FS_KEY_DESC_PREFIX, FS_KEY_DESC_PREFIX_SIZE);
res = validate_user_key(crypt_info, &ctx, raw_key, FS_KEY_DESC_PREFIX);
if (res && inode->i_sb->s_cop->key_prefix) {
u8 *prefix = NULL;
int prefix_size, res2;
prefix_size = inode->i_sb->s_cop->key_prefix(inode, &prefix);
res2 = validate_user_key(crypt_info, &ctx, raw_key,
prefix, prefix_size);
int res2 = validate_user_key(crypt_info, &ctx, raw_key,
inode->i_sb->s_cop->key_prefix);
if (res2) {
if (res2 == -ENOKEY)
res = -ENOKEY;
......@@ -270,7 +258,6 @@ int fscrypt_get_crypt_info(struct inode *inode)
} else if (res) {
goto out;
}
got_key:
ctfm = crypto_alloc_skcipher(cipher_str, 0, 0);
if (!ctfm || IS_ERR(ctfm)) {
res = ctfm ? PTR_ERR(ctfm) : -ENOMEM;
......
......@@ -13,37 +13,20 @@
#include <linux/mount.h>
#include "fscrypt_private.h"
static int inode_has_encryption_context(struct inode *inode)
{
if (!inode->i_sb->s_cop->get_context)
return 0;
return (inode->i_sb->s_cop->get_context(inode, NULL, 0L) > 0);
}
/*
* check whether the policy is consistent with the encryption context
* for the inode
* check whether an encryption policy is consistent with an encryption context
*/
static int is_encryption_context_consistent_with_policy(struct inode *inode,
static bool is_encryption_context_consistent_with_policy(
const struct fscrypt_context *ctx,
const struct fscrypt_policy *policy)
{
struct fscrypt_context ctx;
int res;
if (!inode->i_sb->s_cop->get_context)
return 0;
res = inode->i_sb->s_cop->get_context(inode, &ctx, sizeof(ctx));
if (res != sizeof(ctx))
return 0;
return (memcmp(ctx.master_key_descriptor, policy->master_key_descriptor,
FS_KEY_DESCRIPTOR_SIZE) == 0 &&
(ctx.flags == policy->flags) &&
(ctx.contents_encryption_mode ==
policy->contents_encryption_mode) &&
(ctx.filenames_encryption_mode ==
policy->filenames_encryption_mode));
return memcmp(ctx->master_key_descriptor, policy->master_key_descriptor,
FS_KEY_DESCRIPTOR_SIZE) == 0 &&
(ctx->flags == policy->flags) &&
(ctx->contents_encryption_mode ==
policy->contents_encryption_mode) &&
(ctx->filenames_encryption_mode ==
policy->filenames_encryption_mode);
}
static int create_encryption_context_from_policy(struct inode *inode,
......@@ -66,20 +49,12 @@ static int create_encryption_context_from_policy(struct inode *inode,
FS_KEY_DESCRIPTOR_SIZE);
if (!fscrypt_valid_contents_enc_mode(
policy->contents_encryption_mode)) {
printk(KERN_WARNING
"%s: Invalid contents encryption mode %d\n", __func__,
policy->contents_encryption_mode);
policy->contents_encryption_mode))
return -EINVAL;
}
if (!fscrypt_valid_filenames_enc_mode(
policy->filenames_encryption_mode)) {
printk(KERN_WARNING
"%s: Invalid filenames encryption mode %d\n", __func__,
policy->filenames_encryption_mode);
policy->filenames_encryption_mode))
return -EINVAL;
}
if (policy->flags & ~FS_POLICY_FLAGS_VALID)
return -EINVAL;
......@@ -98,6 +73,7 @@ int fscrypt_ioctl_set_policy(struct file *filp, const void __user *arg)
struct fscrypt_policy policy;
struct inode *inode = file_inode(filp);
int ret;
struct fscrypt_context ctx;
if (copy_from_user(&policy, arg, sizeof(policy)))
return -EFAULT;
......@@ -114,9 +90,10 @@ int fscrypt_ioctl_set_policy(struct file *filp, const void __user *arg)
inode_lock(inode);
if (!inode_has_encryption_context(inode)) {
ret = inode->i_sb->s_cop->get_context(inode, &ctx, sizeof(ctx));
if (ret == -ENODATA) {
if (!S_ISDIR(inode->i_mode))
ret = -EINVAL;
ret = -ENOTDIR;
else if (!inode->i_sb->s_cop->empty_dir)
ret = -EOPNOTSUPP;
else if (!inode->i_sb->s_cop->empty_dir(inode))
......@@ -124,12 +101,14 @@ int fscrypt_ioctl_set_policy(struct file *filp, const void __user *arg)
else
ret = create_encryption_context_from_policy(inode,
&policy);
} else if (!is_encryption_context_consistent_with_policy(inode,
&policy)) {
printk(KERN_WARNING
"%s: Policy inconsistent with encryption context\n",
__func__);
ret = -EINVAL;
} else if (ret == sizeof(ctx) &&
is_encryption_context_consistent_with_policy(&ctx,
&policy)) {
/* The file already uses the same encryption policy. */
ret = 0;
} else if (ret >= 0 || ret == -ERANGE) {
/* The file already uses a different encryption policy. */
ret = -EEXIST;
}
inode_unlock(inode);
......@@ -151,8 +130,10 @@ int fscrypt_ioctl_get_policy(struct file *filp, void __user *arg)
return -ENODATA;
res = inode->i_sb->s_cop->get_context(inode, &ctx, sizeof(ctx));
if (res < 0 && res != -ERANGE)
return res;
if (res != sizeof(