forked from Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
902 lines
25 KiB
902 lines
25 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
|
/** |
|
* eCryptfs: Linux filesystem encryption layer |
|
* |
|
* Copyright (C) 1997-2003 Erez Zadok |
|
* Copyright (C) 2001-2003 Stony Brook University |
|
* Copyright (C) 2004-2007 International Business Machines Corp. |
|
* Author(s): Michael A. Halcrow <[email protected]> |
|
* Michael C. Thompson <[email protected]> |
|
* Tyler Hicks <[email protected]> |
|
*/ |
|
|
|
#include <linux/dcache.h> |
|
#include <linux/file.h> |
|
#include <linux/module.h> |
|
#include <linux/namei.h> |
|
#include <linux/skbuff.h> |
|
#include <linux/mount.h> |
|
#include <linux/pagemap.h> |
|
#include <linux/key.h> |
|
#include <linux/parser.h> |
|
#include <linux/fs_stack.h> |
|
#include <linux/slab.h> |
|
#include <linux/magic.h> |
|
#include "ecryptfs_kernel.h" |
|
|
|
/** |
|
* Module parameter that defines the ecryptfs_verbosity level. |
|
*/ |
|
int ecryptfs_verbosity = 0; |
|
|
|
module_param(ecryptfs_verbosity, int, 0); |
|
MODULE_PARM_DESC(ecryptfs_verbosity, |
|
"Initial verbosity level (0 or 1; defaults to " |
|
"0, which is Quiet)"); |
|
|
|
/** |
|
* Module parameter that defines the number of message buffer elements |
|
*/ |
|
unsigned int ecryptfs_message_buf_len = ECRYPTFS_DEFAULT_MSG_CTX_ELEMS; |
|
|
|
module_param(ecryptfs_message_buf_len, uint, 0); |
|
MODULE_PARM_DESC(ecryptfs_message_buf_len, |
|
"Number of message buffer elements"); |
|
|
|
/** |
|
* Module parameter that defines the maximum guaranteed amount of time to wait |
|
* for a response from ecryptfsd. The actual sleep time will be, more than |
|
* likely, a small amount greater than this specified value, but only less if |
|
* the message successfully arrives. |
|
*/ |
|
signed long ecryptfs_message_wait_timeout = ECRYPTFS_MAX_MSG_CTX_TTL / HZ; |
|
|
|
module_param(ecryptfs_message_wait_timeout, long, 0); |
|
MODULE_PARM_DESC(ecryptfs_message_wait_timeout, |
|
"Maximum number of seconds that an operation will " |
|
"sleep while waiting for a message response from " |
|
"userspace"); |
|
|
|
/** |
|
* Module parameter that is an estimate of the maximum number of users |
|
* that will be concurrently using eCryptfs. Set this to the right |
|
* value to balance performance and memory use. |
|
*/ |
|
unsigned int ecryptfs_number_of_users = ECRYPTFS_DEFAULT_NUM_USERS; |
|
|
|
module_param(ecryptfs_number_of_users, uint, 0); |
|
MODULE_PARM_DESC(ecryptfs_number_of_users, "An estimate of the number of " |
|
"concurrent users of eCryptfs"); |
|
|
|
void __ecryptfs_printk(const char *fmt, ...) |
|
{ |
|
va_list args; |
|
va_start(args, fmt); |
|
if (fmt[1] == '7') { /* KERN_DEBUG */ |
|
if (ecryptfs_verbosity >= 1) |
|
vprintk(fmt, args); |
|
} else |
|
vprintk(fmt, args); |
|
va_end(args); |
|
} |
|
|
|
/** |
|
* ecryptfs_init_lower_file |
|
* @ecryptfs_dentry: Fully initialized eCryptfs dentry object, with |
|
* the lower dentry and the lower mount set |
|
* |
|
* eCryptfs only ever keeps a single open file for every lower |
|
* inode. All I/O operations to the lower inode occur through that |
|
* file. When the first eCryptfs dentry that interposes with the first |
|
* lower dentry for that inode is created, this function creates the |
|
* lower file struct and associates it with the eCryptfs |
|
* inode. When all eCryptfs files associated with the inode are released, the |
|
* file is closed. |
|
* |
|
* The lower file will be opened with read/write permissions, if |
|
* possible. Otherwise, it is opened read-only. |
|
* |
|
* This function does nothing if a lower file is already |
|
* associated with the eCryptfs inode. |
|
* |
|
* Returns zero on success; non-zero otherwise |
|
*/ |
|
static int ecryptfs_init_lower_file(struct dentry *dentry, |
|
struct file **lower_file) |
|
{ |
|
const struct cred *cred = current_cred(); |
|
struct path *path = ecryptfs_dentry_to_lower_path(dentry); |
|
int rc; |
|
|
|
rc = ecryptfs_privileged_open(lower_file, path->dentry, path->mnt, |
|
cred); |
|
if (rc) { |
|
printk(KERN_ERR "Error opening lower file " |
|
"for lower_dentry [0x%p] and lower_mnt [0x%p]; " |
|
"rc = [%d]\n", path->dentry, path->mnt, rc); |
|
(*lower_file) = NULL; |
|
} |
|
return rc; |
|
} |
|
|
|
int ecryptfs_get_lower_file(struct dentry *dentry, struct inode *inode) |
|
{ |
|
struct ecryptfs_inode_info *inode_info; |
|
int count, rc = 0; |
|
|
|
inode_info = ecryptfs_inode_to_private(inode); |
|
mutex_lock(&inode_info->lower_file_mutex); |
|
count = atomic_inc_return(&inode_info->lower_file_count); |
|
if (WARN_ON_ONCE(count < 1)) |
|
rc = -EINVAL; |
|
else if (count == 1) { |
|
rc = ecryptfs_init_lower_file(dentry, |
|
&inode_info->lower_file); |
|
if (rc) |
|
atomic_set(&inode_info->lower_file_count, 0); |
|
} |
|
mutex_unlock(&inode_info->lower_file_mutex); |
|
return rc; |
|
} |
|
|
|
void ecryptfs_put_lower_file(struct inode *inode) |
|
{ |
|
struct ecryptfs_inode_info *inode_info; |
|
|
|
inode_info = ecryptfs_inode_to_private(inode); |
|
if (atomic_dec_and_mutex_lock(&inode_info->lower_file_count, |
|
&inode_info->lower_file_mutex)) { |
|
filemap_write_and_wait(inode->i_mapping); |
|
fput(inode_info->lower_file); |
|
inode_info->lower_file = NULL; |
|
mutex_unlock(&inode_info->lower_file_mutex); |
|
} |
|
} |
|
|
|
enum { ecryptfs_opt_sig, ecryptfs_opt_ecryptfs_sig, |
|
ecryptfs_opt_cipher, ecryptfs_opt_ecryptfs_cipher, |
|
ecryptfs_opt_ecryptfs_key_bytes, |
|
ecryptfs_opt_passthrough, ecryptfs_opt_xattr_metadata, |
|
ecryptfs_opt_encrypted_view, ecryptfs_opt_fnek_sig, |
|
ecryptfs_opt_fn_cipher, ecryptfs_opt_fn_cipher_key_bytes, |
|
ecryptfs_opt_unlink_sigs, ecryptfs_opt_mount_auth_tok_only, |
|
ecryptfs_opt_check_dev_ruid, |
|
ecryptfs_opt_err }; |
|
|
|
static const match_table_t tokens = { |
|
{ecryptfs_opt_sig, "sig=%s"}, |
|
{ecryptfs_opt_ecryptfs_sig, "ecryptfs_sig=%s"}, |
|
{ecryptfs_opt_cipher, "cipher=%s"}, |
|
{ecryptfs_opt_ecryptfs_cipher, "ecryptfs_cipher=%s"}, |
|
{ecryptfs_opt_ecryptfs_key_bytes, "ecryptfs_key_bytes=%u"}, |
|
{ecryptfs_opt_passthrough, "ecryptfs_passthrough"}, |
|
{ecryptfs_opt_xattr_metadata, "ecryptfs_xattr_metadata"}, |
|
{ecryptfs_opt_encrypted_view, "ecryptfs_encrypted_view"}, |
|
{ecryptfs_opt_fnek_sig, "ecryptfs_fnek_sig=%s"}, |
|
{ecryptfs_opt_fn_cipher, "ecryptfs_fn_cipher=%s"}, |
|
{ecryptfs_opt_fn_cipher_key_bytes, "ecryptfs_fn_key_bytes=%u"}, |
|
{ecryptfs_opt_unlink_sigs, "ecryptfs_unlink_sigs"}, |
|
{ecryptfs_opt_mount_auth_tok_only, "ecryptfs_mount_auth_tok_only"}, |
|
{ecryptfs_opt_check_dev_ruid, "ecryptfs_check_dev_ruid"}, |
|
{ecryptfs_opt_err, NULL} |
|
}; |
|
|
|
static int ecryptfs_init_global_auth_toks( |
|
struct ecryptfs_mount_crypt_stat *mount_crypt_stat) |
|
{ |
|
struct ecryptfs_global_auth_tok *global_auth_tok; |
|
struct ecryptfs_auth_tok *auth_tok; |
|
int rc = 0; |
|
|
|
list_for_each_entry(global_auth_tok, |
|
&mount_crypt_stat->global_auth_tok_list, |
|
mount_crypt_stat_list) { |
|
rc = ecryptfs_keyring_auth_tok_for_sig( |
|
&global_auth_tok->global_auth_tok_key, &auth_tok, |
|
global_auth_tok->sig); |
|
if (rc) { |
|
printk(KERN_ERR "Could not find valid key in user " |
|
"session keyring for sig specified in mount " |
|
"option: [%s]\n", global_auth_tok->sig); |
|
global_auth_tok->flags |= ECRYPTFS_AUTH_TOK_INVALID; |
|
goto out; |
|
} else { |
|
global_auth_tok->flags &= ~ECRYPTFS_AUTH_TOK_INVALID; |
|
up_write(&(global_auth_tok->global_auth_tok_key)->sem); |
|
} |
|
} |
|
out: |
|
return rc; |
|
} |
|
|
|
static void ecryptfs_init_mount_crypt_stat( |
|
struct ecryptfs_mount_crypt_stat *mount_crypt_stat) |
|
{ |
|
memset((void *)mount_crypt_stat, 0, |
|
sizeof(struct ecryptfs_mount_crypt_stat)); |
|
INIT_LIST_HEAD(&mount_crypt_stat->global_auth_tok_list); |
|
mutex_init(&mount_crypt_stat->global_auth_tok_list_mutex); |
|
mount_crypt_stat->flags |= ECRYPTFS_MOUNT_CRYPT_STAT_INITIALIZED; |
|
} |
|
|
|
/** |
|
* ecryptfs_parse_options |
|
* @sb: The ecryptfs super block |
|
* @options: The options passed to the kernel |
|
* @check_ruid: set to 1 if device uid should be checked against the ruid |
|
* |
|
* Parse mount options: |
|
* debug=N - ecryptfs_verbosity level for debug output |
|
* sig=XXX - description(signature) of the key to use |
|
* |
|
* Returns the dentry object of the lower-level (lower/interposed) |
|
* directory; We want to mount our stackable file system on top of |
|
* that lower directory. |
|
* |
|
* The signature of the key to use must be the description of a key |
|
* already in the keyring. Mounting will fail if the key can not be |
|
* found. |
|
* |
|
* Returns zero on success; non-zero on error |
|
*/ |
|
static int ecryptfs_parse_options(struct ecryptfs_sb_info *sbi, char *options, |
|
uid_t *check_ruid) |
|
{ |
|
char *p; |
|
int rc = 0; |
|
int sig_set = 0; |
|
int cipher_name_set = 0; |
|
int fn_cipher_name_set = 0; |
|
int cipher_key_bytes; |
|
int cipher_key_bytes_set = 0; |
|
int fn_cipher_key_bytes; |
|
int fn_cipher_key_bytes_set = 0; |
|
struct ecryptfs_mount_crypt_stat *mount_crypt_stat = |
|
&sbi->mount_crypt_stat; |
|
substring_t args[MAX_OPT_ARGS]; |
|
int token; |
|
char *sig_src; |
|
char *cipher_name_dst; |
|
char *cipher_name_src; |
|
char *fn_cipher_name_dst; |
|
char *fn_cipher_name_src; |
|
char *fnek_dst; |
|
char *fnek_src; |
|
char *cipher_key_bytes_src; |
|
char *fn_cipher_key_bytes_src; |
|
u8 cipher_code; |
|
|
|
*check_ruid = 0; |
|
|
|
if (!options) { |
|
rc = -EINVAL; |
|
goto out; |
|
} |
|
ecryptfs_init_mount_crypt_stat(mount_crypt_stat); |
|
while ((p = strsep(&options, ",")) != NULL) { |
|
if (!*p) |
|
continue; |
|
token = match_token(p, tokens, args); |
|
switch (token) { |
|
case ecryptfs_opt_sig: |
|
case ecryptfs_opt_ecryptfs_sig: |
|
sig_src = args[0].from; |
|
rc = ecryptfs_add_global_auth_tok(mount_crypt_stat, |
|
sig_src, 0); |
|
if (rc) { |
|
printk(KERN_ERR "Error attempting to register " |
|
"global sig; rc = [%d]\n", rc); |
|
goto out; |
|
} |
|
sig_set = 1; |
|
break; |
|
case ecryptfs_opt_cipher: |
|
case ecryptfs_opt_ecryptfs_cipher: |
|
cipher_name_src = args[0].from; |
|
cipher_name_dst = |
|
mount_crypt_stat-> |
|
global_default_cipher_name; |
|
strncpy(cipher_name_dst, cipher_name_src, |
|
ECRYPTFS_MAX_CIPHER_NAME_SIZE); |
|
cipher_name_dst[ECRYPTFS_MAX_CIPHER_NAME_SIZE] = '\0'; |
|
cipher_name_set = 1; |
|
break; |
|
case ecryptfs_opt_ecryptfs_key_bytes: |
|
cipher_key_bytes_src = args[0].from; |
|
cipher_key_bytes = |
|
(int)simple_strtol(cipher_key_bytes_src, |
|
&cipher_key_bytes_src, 0); |
|
mount_crypt_stat->global_default_cipher_key_size = |
|
cipher_key_bytes; |
|
cipher_key_bytes_set = 1; |
|
break; |
|
case ecryptfs_opt_passthrough: |
|
mount_crypt_stat->flags |= |
|
ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED; |
|
break; |
|
case ecryptfs_opt_xattr_metadata: |
|
mount_crypt_stat->flags |= |
|
ECRYPTFS_XATTR_METADATA_ENABLED; |
|
break; |
|
case ecryptfs_opt_encrypted_view: |
|
mount_crypt_stat->flags |= |
|
ECRYPTFS_XATTR_METADATA_ENABLED; |
|
mount_crypt_stat->flags |= |
|
ECRYPTFS_ENCRYPTED_VIEW_ENABLED; |
|
break; |
|
case ecryptfs_opt_fnek_sig: |
|
fnek_src = args[0].from; |
|
fnek_dst = |
|
mount_crypt_stat->global_default_fnek_sig; |
|
strncpy(fnek_dst, fnek_src, ECRYPTFS_SIG_SIZE_HEX); |
|
mount_crypt_stat->global_default_fnek_sig[ |
|
ECRYPTFS_SIG_SIZE_HEX] = '\0'; |
|
rc = ecryptfs_add_global_auth_tok( |
|
mount_crypt_stat, |
|
mount_crypt_stat->global_default_fnek_sig, |
|
ECRYPTFS_AUTH_TOK_FNEK); |
|
if (rc) { |
|
printk(KERN_ERR "Error attempting to register " |
|
"global fnek sig [%s]; rc = [%d]\n", |
|
mount_crypt_stat->global_default_fnek_sig, |
|
rc); |
|
goto out; |
|
} |
|
mount_crypt_stat->flags |= |
|
(ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES |
|
| ECRYPTFS_GLOBAL_ENCFN_USE_MOUNT_FNEK); |
|
break; |
|
case ecryptfs_opt_fn_cipher: |
|
fn_cipher_name_src = args[0].from; |
|
fn_cipher_name_dst = |
|
mount_crypt_stat->global_default_fn_cipher_name; |
|
strncpy(fn_cipher_name_dst, fn_cipher_name_src, |
|
ECRYPTFS_MAX_CIPHER_NAME_SIZE); |
|
mount_crypt_stat->global_default_fn_cipher_name[ |
|
ECRYPTFS_MAX_CIPHER_NAME_SIZE] = '\0'; |
|
fn_cipher_name_set = 1; |
|
break; |
|
case ecryptfs_opt_fn_cipher_key_bytes: |
|
fn_cipher_key_bytes_src = args[0].from; |
|
fn_cipher_key_bytes = |
|
(int)simple_strtol(fn_cipher_key_bytes_src, |
|
&fn_cipher_key_bytes_src, 0); |
|
mount_crypt_stat->global_default_fn_cipher_key_bytes = |
|
fn_cipher_key_bytes; |
|
fn_cipher_key_bytes_set = 1; |
|
break; |
|
case ecryptfs_opt_unlink_sigs: |
|
mount_crypt_stat->flags |= ECRYPTFS_UNLINK_SIGS; |
|
break; |
|
case ecryptfs_opt_mount_auth_tok_only: |
|
mount_crypt_stat->flags |= |
|
ECRYPTFS_GLOBAL_MOUNT_AUTH_TOK_ONLY; |
|
break; |
|
case ecryptfs_opt_check_dev_ruid: |
|
*check_ruid = 1; |
|
break; |
|
case ecryptfs_opt_err: |
|
default: |
|
printk(KERN_WARNING |
|
"%s: eCryptfs: unrecognized option [%s]\n", |
|
__func__, p); |
|
} |
|
} |
|
if (!sig_set) { |
|
rc = -EINVAL; |
|
ecryptfs_printk(KERN_ERR, "You must supply at least one valid " |
|
"auth tok signature as a mount " |
|
"parameter; see the eCryptfs README\n"); |
|
goto out; |
|
} |
|
if (!cipher_name_set) { |
|
int cipher_name_len = strlen(ECRYPTFS_DEFAULT_CIPHER); |
|
|
|
BUG_ON(cipher_name_len > ECRYPTFS_MAX_CIPHER_NAME_SIZE); |
|
strcpy(mount_crypt_stat->global_default_cipher_name, |
|
ECRYPTFS_DEFAULT_CIPHER); |
|
} |
|
if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) |
|
&& !fn_cipher_name_set) |
|
strcpy(mount_crypt_stat->global_default_fn_cipher_name, |
|
mount_crypt_stat->global_default_cipher_name); |
|
if (!cipher_key_bytes_set) |
|
mount_crypt_stat->global_default_cipher_key_size = 0; |
|
if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) |
|
&& !fn_cipher_key_bytes_set) |
|
mount_crypt_stat->global_default_fn_cipher_key_bytes = |
|
mount_crypt_stat->global_default_cipher_key_size; |
|
|
|
cipher_code = ecryptfs_code_for_cipher_string( |
|
mount_crypt_stat->global_default_cipher_name, |
|
mount_crypt_stat->global_default_cipher_key_size); |
|
if (!cipher_code) { |
|
ecryptfs_printk(KERN_ERR, |
|
"eCryptfs doesn't support cipher: %s\n", |
|
mount_crypt_stat->global_default_cipher_name); |
|
rc = -EINVAL; |
|
goto out; |
|
} |
|
|
|
mutex_lock(&key_tfm_list_mutex); |
|
if (!ecryptfs_tfm_exists(mount_crypt_stat->global_default_cipher_name, |
|
NULL)) { |
|
rc = ecryptfs_add_new_key_tfm( |
|
NULL, mount_crypt_stat->global_default_cipher_name, |
|
mount_crypt_stat->global_default_cipher_key_size); |
|
if (rc) { |
|
printk(KERN_ERR "Error attempting to initialize " |
|
"cipher with name = [%s] and key size = [%td]; " |
|
"rc = [%d]\n", |
|
mount_crypt_stat->global_default_cipher_name, |
|
mount_crypt_stat->global_default_cipher_key_size, |
|
rc); |
|
rc = -EINVAL; |
|
mutex_unlock(&key_tfm_list_mutex); |
|
goto out; |
|
} |
|
} |
|
if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) |
|
&& !ecryptfs_tfm_exists( |
|
mount_crypt_stat->global_default_fn_cipher_name, NULL)) { |
|
rc = ecryptfs_add_new_key_tfm( |
|
NULL, mount_crypt_stat->global_default_fn_cipher_name, |
|
mount_crypt_stat->global_default_fn_cipher_key_bytes); |
|
if (rc) { |
|
printk(KERN_ERR "Error attempting to initialize " |
|
"cipher with name = [%s] and key size = [%td]; " |
|
"rc = [%d]\n", |
|
mount_crypt_stat->global_default_fn_cipher_name, |
|
mount_crypt_stat->global_default_fn_cipher_key_bytes, |
|
rc); |
|
rc = -EINVAL; |
|
mutex_unlock(&key_tfm_list_mutex); |
|
goto out; |
|
} |
|
} |
|
mutex_unlock(&key_tfm_list_mutex); |
|
rc = ecryptfs_init_global_auth_toks(mount_crypt_stat); |
|
if (rc) |
|
printk(KERN_WARNING "One or more global auth toks could not " |
|
"properly register; rc = [%d]\n", rc); |
|
out: |
|
return rc; |
|
} |
|
|
|
struct kmem_cache *ecryptfs_sb_info_cache; |
|
static struct file_system_type ecryptfs_fs_type; |
|
|
|
/** |
|
* ecryptfs_get_sb |
|
* @fs_type |
|
* @flags |
|
* @dev_name: The path to mount over |
|
* @raw_data: The options passed into the kernel |
|
*/ |
|
static struct dentry *ecryptfs_mount(struct file_system_type *fs_type, int flags, |
|
const char *dev_name, void *raw_data) |
|
{ |
|
struct super_block *s; |
|
struct ecryptfs_sb_info *sbi; |
|
struct ecryptfs_mount_crypt_stat *mount_crypt_stat; |
|
struct ecryptfs_dentry_info *root_info; |
|
const char *err = "Getting sb failed"; |
|
struct inode *inode; |
|
struct path path; |
|
uid_t check_ruid; |
|
int rc; |
|
|
|
sbi = kmem_cache_zalloc(ecryptfs_sb_info_cache, GFP_KERNEL); |
|
if (!sbi) { |
|
rc = -ENOMEM; |
|
goto out; |
|
} |
|
|
|
if (!dev_name) { |
|
rc = -EINVAL; |
|
err = "Device name cannot be null"; |
|
goto out; |
|
} |
|
|
|
rc = ecryptfs_parse_options(sbi, raw_data, &check_ruid); |
|
if (rc) { |
|
err = "Error parsing options"; |
|
goto out; |
|
} |
|
mount_crypt_stat = &sbi->mount_crypt_stat; |
|
|
|
s = sget(fs_type, NULL, set_anon_super, flags, NULL); |
|
if (IS_ERR(s)) { |
|
rc = PTR_ERR(s); |
|
goto out; |
|
} |
|
|
|
rc = super_setup_bdi(s); |
|
if (rc) |
|
goto out1; |
|
|
|
ecryptfs_set_superblock_private(s, sbi); |
|
|
|
/* ->kill_sb() will take care of sbi after that point */ |
|
sbi = NULL; |
|
s->s_op = &ecryptfs_sops; |
|
s->s_xattr = ecryptfs_xattr_handlers; |
|
s->s_d_op = &ecryptfs_dops; |
|
|
|
err = "Reading sb failed"; |
|
rc = kern_path(dev_name, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &path); |
|
if (rc) { |
|
ecryptfs_printk(KERN_WARNING, "kern_path() failed\n"); |
|
goto out1; |
|
} |
|
if (path.dentry->d_sb->s_type == &ecryptfs_fs_type) { |
|
rc = -EINVAL; |
|
printk(KERN_ERR "Mount on filesystem of type " |
|
"eCryptfs explicitly disallowed due to " |
|
"known incompatibilities\n"); |
|
goto out_free; |
|
} |
|
|
|
if (mnt_user_ns(path.mnt) != &init_user_ns) { |
|
rc = -EINVAL; |
|
printk(KERN_ERR "Mounting on idmapped mounts currently disallowed\n"); |
|
goto out_free; |
|
} |
|
|
|
if (check_ruid && !uid_eq(d_inode(path.dentry)->i_uid, current_uid())) { |
|
rc = -EPERM; |
|
printk(KERN_ERR "Mount of device (uid: %d) not owned by " |
|
"requested user (uid: %d)\n", |
|
i_uid_read(d_inode(path.dentry)), |
|
from_kuid(&init_user_ns, current_uid())); |
|
goto out_free; |
|
} |
|
|
|
ecryptfs_set_superblock_lower(s, path.dentry->d_sb); |
|
|
|
/** |
|
* Set the POSIX ACL flag based on whether they're enabled in the lower |
|
* mount. |
|
*/ |
|
s->s_flags = flags & ~SB_POSIXACL; |
|
s->s_flags |= path.dentry->d_sb->s_flags & SB_POSIXACL; |
|
|
|
/** |
|
* Force a read-only eCryptfs mount when: |
|
* 1) The lower mount is ro |
|
* 2) The ecryptfs_encrypted_view mount option is specified |
|
*/ |
|
if (sb_rdonly(path.dentry->d_sb) || mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED) |
|
s->s_flags |= SB_RDONLY; |
|
|
|
s->s_maxbytes = path.dentry->d_sb->s_maxbytes; |
|
s->s_blocksize = path.dentry->d_sb->s_blocksize; |
|
s->s_magic = ECRYPTFS_SUPER_MAGIC; |
|
s->s_stack_depth = path.dentry->d_sb->s_stack_depth + 1; |
|
|
|
rc = -EINVAL; |
|
if (s->s_stack_depth > FILESYSTEM_MAX_STACK_DEPTH) { |
|
pr_err("eCryptfs: maximum fs stacking depth exceeded\n"); |
|
goto out_free; |
|
} |
|
|
|
inode = ecryptfs_get_inode(d_inode(path.dentry), s); |
|
rc = PTR_ERR(inode); |
|
if (IS_ERR(inode)) |
|
goto out_free; |
|
|
|
s->s_root = d_make_root(inode); |
|
if (!s->s_root) { |
|
rc = -ENOMEM; |
|
goto out_free; |
|
} |
|
|
|
rc = -ENOMEM; |
|
root_info = kmem_cache_zalloc(ecryptfs_dentry_info_cache, GFP_KERNEL); |
|
if (!root_info) |
|
goto out_free; |
|
|
|
/* ->kill_sb() will take care of root_info */ |
|
ecryptfs_set_dentry_private(s->s_root, root_info); |
|
root_info->lower_path = path; |
|
|
|
s->s_flags |= SB_ACTIVE; |
|
return dget(s->s_root); |
|
|
|
out_free: |
|
path_put(&path); |
|
out1: |
|
deactivate_locked_super(s); |
|
out: |
|
if (sbi) { |
|
ecryptfs_destroy_mount_crypt_stat(&sbi->mount_crypt_stat); |
|
kmem_cache_free(ecryptfs_sb_info_cache, sbi); |
|
} |
|
printk(KERN_ERR "%s; rc = [%d]\n", err, rc); |
|
return ERR_PTR(rc); |
|
} |
|
|
|
/** |
|
* ecryptfs_kill_block_super |
|
* @sb: The ecryptfs super block |
|
* |
|
* Used to bring the superblock down and free the private data. |
|
*/ |
|
static void ecryptfs_kill_block_super(struct super_block *sb) |
|
{ |
|
struct ecryptfs_sb_info *sb_info = ecryptfs_superblock_to_private(sb); |
|
kill_anon_super(sb); |
|
if (!sb_info) |
|
return; |
|
ecryptfs_destroy_mount_crypt_stat(&sb_info->mount_crypt_stat); |
|
kmem_cache_free(ecryptfs_sb_info_cache, sb_info); |
|
} |
|
|
|
static struct file_system_type ecryptfs_fs_type = { |
|
.owner = THIS_MODULE, |
|
.name = "ecryptfs", |
|
.mount = ecryptfs_mount, |
|
.kill_sb = ecryptfs_kill_block_super, |
|
.fs_flags = 0 |
|
}; |
|
MODULE_ALIAS_FS("ecryptfs"); |
|
|
|
/** |
|
* inode_info_init_once |
|
* |
|
* Initializes the ecryptfs_inode_info_cache when it is created |
|
*/ |
|
static void |
|
inode_info_init_once(void *vptr) |
|
{ |
|
struct ecryptfs_inode_info *ei = (struct ecryptfs_inode_info *)vptr; |
|
|
|
inode_init_once(&ei->vfs_inode); |
|
} |
|
|
|
static struct ecryptfs_cache_info { |
|
struct kmem_cache **cache; |
|
const char *name; |
|
size_t size; |
|
slab_flags_t flags; |
|
void (*ctor)(void *obj); |
|
} ecryptfs_cache_infos[] = { |
|
{ |
|
.cache = &ecryptfs_auth_tok_list_item_cache, |
|
.name = "ecryptfs_auth_tok_list_item", |
|
.size = sizeof(struct ecryptfs_auth_tok_list_item), |
|
}, |
|
{ |
|
.cache = &ecryptfs_file_info_cache, |
|
.name = "ecryptfs_file_cache", |
|
.size = sizeof(struct ecryptfs_file_info), |
|
}, |
|
{ |
|
.cache = &ecryptfs_dentry_info_cache, |
|
.name = "ecryptfs_dentry_info_cache", |
|
.size = sizeof(struct ecryptfs_dentry_info), |
|
}, |
|
{ |
|
.cache = &ecryptfs_inode_info_cache, |
|
.name = "ecryptfs_inode_cache", |
|
.size = sizeof(struct ecryptfs_inode_info), |
|
.flags = SLAB_ACCOUNT, |
|
.ctor = inode_info_init_once, |
|
}, |
|
{ |
|
.cache = &ecryptfs_sb_info_cache, |
|
.name = "ecryptfs_sb_cache", |
|
.size = sizeof(struct ecryptfs_sb_info), |
|
}, |
|
{ |
|
.cache = &ecryptfs_header_cache, |
|
.name = "ecryptfs_headers", |
|
.size = PAGE_SIZE, |
|
}, |
|
{ |
|
.cache = &ecryptfs_xattr_cache, |
|
.name = "ecryptfs_xattr_cache", |
|
.size = PAGE_SIZE, |
|
}, |
|
{ |
|
.cache = &ecryptfs_key_record_cache, |
|
.name = "ecryptfs_key_record_cache", |
|
.size = sizeof(struct ecryptfs_key_record), |
|
}, |
|
{ |
|
.cache = &ecryptfs_key_sig_cache, |
|
.name = "ecryptfs_key_sig_cache", |
|
.size = sizeof(struct ecryptfs_key_sig), |
|
}, |
|
{ |
|
.cache = &ecryptfs_global_auth_tok_cache, |
|
.name = "ecryptfs_global_auth_tok_cache", |
|
.size = sizeof(struct ecryptfs_global_auth_tok), |
|
}, |
|
{ |
|
.cache = &ecryptfs_key_tfm_cache, |
|
.name = "ecryptfs_key_tfm_cache", |
|
.size = sizeof(struct ecryptfs_key_tfm), |
|
}, |
|
}; |
|
|
|
static void ecryptfs_free_kmem_caches(void) |
|
{ |
|
int i; |
|
|
|
/* |
|
* Make sure all delayed rcu free inodes are flushed before we |
|
* destroy cache. |
|
*/ |
|
rcu_barrier(); |
|
|
|
for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) { |
|
struct ecryptfs_cache_info *info; |
|
|
|
info = &ecryptfs_cache_infos[i]; |
|
kmem_cache_destroy(*(info->cache)); |
|
} |
|
} |
|
|
|
/** |
|
* ecryptfs_init_kmem_caches |
|
* |
|
* Returns zero on success; non-zero otherwise |
|
*/ |
|
static int ecryptfs_init_kmem_caches(void) |
|
{ |
|
int i; |
|
|
|
for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) { |
|
struct ecryptfs_cache_info *info; |
|
|
|
info = &ecryptfs_cache_infos[i]; |
|
*(info->cache) = kmem_cache_create(info->name, info->size, 0, |
|
SLAB_HWCACHE_ALIGN | info->flags, info->ctor); |
|
if (!*(info->cache)) { |
|
ecryptfs_free_kmem_caches(); |
|
ecryptfs_printk(KERN_WARNING, "%s: " |
|
"kmem_cache_create failed\n", |
|
info->name); |
|
return -ENOMEM; |
|
} |
|
} |
|
return 0; |
|
} |
|
|
|
static struct kobject *ecryptfs_kobj; |
|
|
|
static ssize_t version_show(struct kobject *kobj, |
|
struct kobj_attribute *attr, char *buff) |
|
{ |
|
return snprintf(buff, PAGE_SIZE, "%d\n", ECRYPTFS_VERSIONING_MASK); |
|
} |
|
|
|
static struct kobj_attribute version_attr = __ATTR_RO(version); |
|
|
|
static struct attribute *attributes[] = { |
|
&version_attr.attr, |
|
NULL, |
|
}; |
|
|
|
static const struct attribute_group attr_group = { |
|
.attrs = attributes, |
|
}; |
|
|
|
static int do_sysfs_registration(void) |
|
{ |
|
int rc; |
|
|
|
ecryptfs_kobj = kobject_create_and_add("ecryptfs", fs_kobj); |
|
if (!ecryptfs_kobj) { |
|
printk(KERN_ERR "Unable to create ecryptfs kset\n"); |
|
rc = -ENOMEM; |
|
goto out; |
|
} |
|
rc = sysfs_create_group(ecryptfs_kobj, &attr_group); |
|
if (rc) { |
|
printk(KERN_ERR |
|
"Unable to create ecryptfs version attributes\n"); |
|
kobject_put(ecryptfs_kobj); |
|
} |
|
out: |
|
return rc; |
|
} |
|
|
|
static void do_sysfs_unregistration(void) |
|
{ |
|
sysfs_remove_group(ecryptfs_kobj, &attr_group); |
|
kobject_put(ecryptfs_kobj); |
|
} |
|
|
|
static int __init ecryptfs_init(void) |
|
{ |
|
int rc; |
|
|
|
if (ECRYPTFS_DEFAULT_EXTENT_SIZE > PAGE_SIZE) { |
|
rc = -EINVAL; |
|
ecryptfs_printk(KERN_ERR, "The eCryptfs extent size is " |
|
"larger than the host's page size, and so " |
|
"eCryptfs cannot run on this system. The " |
|
"default eCryptfs extent size is [%u] bytes; " |
|
"the page size is [%lu] bytes.\n", |
|
ECRYPTFS_DEFAULT_EXTENT_SIZE, |
|
(unsigned long)PAGE_SIZE); |
|
goto out; |
|
} |
|
rc = ecryptfs_init_kmem_caches(); |
|
if (rc) { |
|
printk(KERN_ERR |
|
"Failed to allocate one or more kmem_cache objects\n"); |
|
goto out; |
|
} |
|
rc = do_sysfs_registration(); |
|
if (rc) { |
|
printk(KERN_ERR "sysfs registration failed\n"); |
|
goto out_free_kmem_caches; |
|
} |
|
rc = ecryptfs_init_kthread(); |
|
if (rc) { |
|
printk(KERN_ERR "%s: kthread initialization failed; " |
|
"rc = [%d]\n", __func__, rc); |
|
goto out_do_sysfs_unregistration; |
|
} |
|
rc = ecryptfs_init_messaging(); |
|
if (rc) { |
|
printk(KERN_ERR "Failure occurred while attempting to " |
|
"initialize the communications channel to " |
|
"ecryptfsd\n"); |
|
goto out_destroy_kthread; |
|
} |
|
rc = ecryptfs_init_crypto(); |
|
if (rc) { |
|
printk(KERN_ERR "Failure whilst attempting to init crypto; " |
|
"rc = [%d]\n", rc); |
|
goto out_release_messaging; |
|
} |
|
rc = register_filesystem(&ecryptfs_fs_type); |
|
if (rc) { |
|
printk(KERN_ERR "Failed to register filesystem\n"); |
|
goto out_destroy_crypto; |
|
} |
|
if (ecryptfs_verbosity > 0) |
|
printk(KERN_CRIT "eCryptfs verbosity set to %d. Secret values " |
|
"will be written to the syslog!\n", ecryptfs_verbosity); |
|
|
|
goto out; |
|
out_destroy_crypto: |
|
ecryptfs_destroy_crypto(); |
|
out_release_messaging: |
|
ecryptfs_release_messaging(); |
|
out_destroy_kthread: |
|
ecryptfs_destroy_kthread(); |
|
out_do_sysfs_unregistration: |
|
do_sysfs_unregistration(); |
|
out_free_kmem_caches: |
|
ecryptfs_free_kmem_caches(); |
|
out: |
|
return rc; |
|
} |
|
|
|
static void __exit ecryptfs_exit(void) |
|
{ |
|
int rc; |
|
|
|
rc = ecryptfs_destroy_crypto(); |
|
if (rc) |
|
printk(KERN_ERR "Failure whilst attempting to destroy crypto; " |
|
"rc = [%d]\n", rc); |
|
ecryptfs_release_messaging(); |
|
ecryptfs_destroy_kthread(); |
|
do_sysfs_unregistration(); |
|
unregister_filesystem(&ecryptfs_fs_type); |
|
ecryptfs_free_kmem_caches(); |
|
} |
|
|
|
MODULE_AUTHOR("Michael A. Halcrow <[email protected]>"); |
|
MODULE_DESCRIPTION("eCryptfs"); |
|
|
|
MODULE_LICENSE("GPL"); |
|
|
|
module_init(ecryptfs_init) |
|
module_exit(ecryptfs_exit)
|
|
|