vfs-6.13.ecryptfs.mount.api

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Merge tag 'vfs-6.13.ecryptfs.mount.api' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

Pull ecryptfs mount api conversion from Christian Brauner:
 "Convert ecryptfs to the new mount api"

* tag 'vfs-6.13.ecryptfs.mount.api' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
  ecryptfs: Fix spelling mistake "validationg" -> "validating"
  ecryptfs: Convert ecryptfs to use the new mount API
  ecryptfs: Factor out mount option validation
This commit is contained in:
Linus Torvalds 2024-11-26 13:39:02 -08:00
commit 6daf0882c6

View File

@ -15,10 +15,10 @@
#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_context.h>
#include <linux/fs_parser.h>
#include <linux/fs_stack.h>
#include <linux/slab.h>
#include <linux/magic.h>
@ -153,32 +153,30 @@ void ecryptfs_put_lower_file(struct inode *inode)
}
}
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 };
enum {
Opt_sig, Opt_ecryptfs_sig, Opt_cipher, Opt_ecryptfs_cipher,
Opt_ecryptfs_key_bytes, Opt_passthrough, Opt_xattr_metadata,
Opt_encrypted_view, Opt_fnek_sig, Opt_fn_cipher,
Opt_fn_cipher_key_bytes, Opt_unlink_sigs, Opt_mount_auth_tok_only,
Opt_check_dev_ruid
};
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 const struct fs_parameter_spec ecryptfs_fs_param_spec[] = {
fsparam_string ("sig", Opt_sig),
fsparam_string ("ecryptfs_sig", Opt_ecryptfs_sig),
fsparam_string ("cipher", Opt_cipher),
fsparam_string ("ecryptfs_cipher", Opt_ecryptfs_cipher),
fsparam_u32 ("ecryptfs_key_bytes", Opt_ecryptfs_key_bytes),
fsparam_flag ("ecryptfs_passthrough", Opt_passthrough),
fsparam_flag ("ecryptfs_xattr_metadata", Opt_xattr_metadata),
fsparam_flag ("ecryptfs_encrypted_view", Opt_encrypted_view),
fsparam_string ("ecryptfs_fnek_sig", Opt_fnek_sig),
fsparam_string ("ecryptfs_fn_cipher", Opt_fn_cipher),
fsparam_u32 ("ecryptfs_fn_key_bytes", Opt_fn_cipher_key_bytes),
fsparam_flag ("ecryptfs_unlink_sigs", Opt_unlink_sigs),
fsparam_flag ("ecryptfs_mount_auth_tok_only", Opt_mount_auth_tok_only),
fsparam_flag ("ecryptfs_check_dev_ruid", Opt_check_dev_ruid),
{}
};
static int ecryptfs_init_global_auth_toks(
@ -219,19 +217,20 @@ static void ecryptfs_init_mount_crypt_stat(
mount_crypt_stat->flags |= ECRYPTFS_MOUNT_CRYPT_STAT_INITIALIZED;
}
struct ecryptfs_fs_context {
/* Mount option status trackers */
bool check_ruid;
bool sig_set;
bool cipher_name_set;
bool cipher_key_bytes_set;
bool fn_cipher_name_set;
bool fn_cipher_key_bytes_set;
};
/**
* ecryptfs_parse_options
* @sbi: 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.
* ecryptfs_parse_param
* @fc: The ecryptfs filesystem context
* @param: The mount parameter to parse
*
* 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
@ -239,143 +238,118 @@ static void ecryptfs_init_mount_crypt_stat(
*
* Returns zero on success; non-zero on error
*/
static int ecryptfs_parse_options(struct ecryptfs_sb_info *sbi, char *options,
uid_t *check_ruid)
static int ecryptfs_parse_param(
struct fs_context *fc,
struct fs_parameter *param)
{
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;
int rc;
int opt;
struct fs_parse_result result;
struct ecryptfs_fs_context *ctx = fc->fs_private;
struct ecryptfs_sb_info *sbi = fc->s_fs_info;
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_src;
char *fn_cipher_name_src;
char *fnek_src;
char *cipher_key_bytes_src;
char *fn_cipher_key_bytes_src;
u8 cipher_code;
*check_ruid = 0;
opt = fs_parse(fc, ecryptfs_fs_param_spec, param, &result);
if (opt < 0)
return opt;
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;
strscpy(mount_crypt_stat->global_default_cipher_name,
cipher_name_src);
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;
strscpy(mount_crypt_stat->global_default_fnek_sig,
fnek_src);
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;
strscpy(mount_crypt_stat->global_default_fn_cipher_name,
fn_cipher_name_src);
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);
switch (opt) {
case Opt_sig:
case Opt_ecryptfs_sig:
rc = ecryptfs_add_global_auth_tok(mount_crypt_stat,
param->string, 0);
if (rc) {
printk(KERN_ERR "Error attempting to register "
"global sig; rc = [%d]\n", rc);
return rc;
}
ctx->sig_set = 1;
break;
case Opt_cipher:
case Opt_ecryptfs_cipher:
strscpy(mount_crypt_stat->global_default_cipher_name,
param->string);
ctx->cipher_name_set = 1;
break;
case Opt_ecryptfs_key_bytes:
mount_crypt_stat->global_default_cipher_key_size =
result.uint_32;
ctx->cipher_key_bytes_set = 1;
break;
case Opt_passthrough:
mount_crypt_stat->flags |=
ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED;
break;
case Opt_xattr_metadata:
mount_crypt_stat->flags |= ECRYPTFS_XATTR_METADATA_ENABLED;
break;
case Opt_encrypted_view:
mount_crypt_stat->flags |= ECRYPTFS_XATTR_METADATA_ENABLED;
mount_crypt_stat->flags |= ECRYPTFS_ENCRYPTED_VIEW_ENABLED;
break;
case Opt_fnek_sig:
strscpy(mount_crypt_stat->global_default_fnek_sig,
param->string);
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);
return rc;
}
mount_crypt_stat->flags |=
(ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES
| ECRYPTFS_GLOBAL_ENCFN_USE_MOUNT_FNEK);
break;
case Opt_fn_cipher:
strscpy(mount_crypt_stat->global_default_fn_cipher_name,
param->string);
ctx->fn_cipher_name_set = 1;
break;
case Opt_fn_cipher_key_bytes:
mount_crypt_stat->global_default_fn_cipher_key_bytes =
result.uint_32;
ctx->fn_cipher_key_bytes_set = 1;
break;
case Opt_unlink_sigs:
mount_crypt_stat->flags |= ECRYPTFS_UNLINK_SIGS;
break;
case Opt_mount_auth_tok_only:
mount_crypt_stat->flags |= ECRYPTFS_GLOBAL_MOUNT_AUTH_TOK_ONLY;
break;
case Opt_check_dev_ruid:
ctx->check_ruid = 1;
break;
default:
return -EINVAL;
}
if (!sig_set) {
return 0;
}
static int ecryptfs_validate_options(struct fs_context *fc)
{
int rc = 0;
u8 cipher_code;
struct ecryptfs_fs_context *ctx = fc->fs_private;
struct ecryptfs_sb_info *sbi = fc->s_fs_info;
struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
mount_crypt_stat = &sbi->mount_crypt_stat;
if (!ctx->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) {
if (!ctx->cipher_name_set) {
int cipher_name_len = strlen(ECRYPTFS_DEFAULT_CIPHER);
BUG_ON(cipher_name_len > ECRYPTFS_MAX_CIPHER_NAME_SIZE);
@ -383,13 +357,13 @@ static int ecryptfs_parse_options(struct ecryptfs_sb_info *sbi, char *options,
ECRYPTFS_DEFAULT_CIPHER);
}
if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES)
&& !fn_cipher_name_set)
&& !ctx->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)
if (!ctx->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)
&& !ctx->fn_cipher_key_bytes_set)
mount_crypt_stat->global_default_fn_cipher_key_bytes =
mount_crypt_stat->global_default_cipher_key_size;
@ -453,45 +427,35 @@ struct kmem_cache *ecryptfs_sb_info_cache;
static struct file_system_type ecryptfs_fs_type;
/*
* ecryptfs_mount
* @fs_type: The filesystem type that the superblock should belong to
* @flags: The flags associated with the mount
* @dev_name: The path to mount over
* @raw_data: The options passed into the kernel
* ecryptfs_get_tree
* @fc: The filesystem context
*/
static struct dentry *ecryptfs_mount(struct file_system_type *fs_type, int flags,
const char *dev_name, void *raw_data)
static int ecryptfs_get_tree(struct fs_context *fc)
{
struct super_block *s;
struct ecryptfs_sb_info *sbi;
struct ecryptfs_fs_context *ctx = fc->fs_private;
struct ecryptfs_sb_info *sbi = fc->s_fs_info;
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) {
if (!fc->source) {
rc = -EINVAL;
err = "Device name cannot be null";
goto out;
}
rc = ecryptfs_parse_options(sbi, raw_data, &check_ruid);
mount_crypt_stat = &sbi->mount_crypt_stat;
rc = ecryptfs_validate_options(fc);
if (rc) {
err = "Error parsing options";
err = "Error validating options";
goto out;
}
mount_crypt_stat = &sbi->mount_crypt_stat;
s = sget(fs_type, NULL, set_anon_super, flags, NULL);
s = sget_fc(fc, NULL, set_anon_super_fc);
if (IS_ERR(s)) {
rc = PTR_ERR(s);
goto out;
@ -510,7 +474,7 @@ static struct dentry *ecryptfs_mount(struct file_system_type *fs_type, int flags
s->s_d_op = &ecryptfs_dops;
err = "Reading sb failed";
rc = kern_path(dev_name, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &path);
rc = kern_path(fc->source, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &path);
if (rc) {
ecryptfs_printk(KERN_WARNING, "kern_path() failed\n");
goto out1;
@ -529,7 +493,8 @@ static struct dentry *ecryptfs_mount(struct file_system_type *fs_type, int flags
goto out_free;
}
if (check_ruid && !uid_eq(d_inode(path.dentry)->i_uid, current_uid())) {
if (ctx->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",
@ -544,7 +509,7 @@ static struct dentry *ecryptfs_mount(struct file_system_type *fs_type, int flags
* Set the POSIX ACL flag based on whether they're enabled in the lower
* mount.
*/
s->s_flags = flags & ~SB_POSIXACL;
s->s_flags = fc->sb_flags & ~SB_POSIXACL;
s->s_flags |= path.dentry->d_sb->s_flags & SB_POSIXACL;
/**
@ -587,19 +552,19 @@ static struct dentry *ecryptfs_mount(struct file_system_type *fs_type, int flags
root_info->lower_path = path;
s->s_flags |= SB_ACTIVE;
return dget(s->s_root);
fc->root = dget(s->s_root);
return 0;
out_free:
path_put(&path);
out1:
deactivate_locked_super(s);
out:
if (sbi) {
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);
return rc;
}
/**
@ -618,10 +583,54 @@ static void ecryptfs_kill_block_super(struct super_block *sb)
kmem_cache_free(ecryptfs_sb_info_cache, sb_info);
}
static void ecryptfs_free_fc(struct fs_context *fc)
{
struct ecryptfs_fs_context *ctx = fc->fs_private;
struct ecryptfs_sb_info *sbi = fc->s_fs_info;
kfree(ctx);
if (sbi) {
ecryptfs_destroy_mount_crypt_stat(&sbi->mount_crypt_stat);
kmem_cache_free(ecryptfs_sb_info_cache, sbi);
}
}
static const struct fs_context_operations ecryptfs_context_ops = {
.free = ecryptfs_free_fc,
.parse_param = ecryptfs_parse_param,
.get_tree = ecryptfs_get_tree,
.reconfigure = NULL,
};
static int ecryptfs_init_fs_context(struct fs_context *fc)
{
struct ecryptfs_fs_context *ctx;
struct ecryptfs_sb_info *sbi = NULL;
ctx = kzalloc(sizeof(struct ecryptfs_fs_context), GFP_KERNEL);
if (!ctx)
return -ENOMEM;
sbi = kmem_cache_zalloc(ecryptfs_sb_info_cache, GFP_KERNEL);
if (!sbi) {
kfree(ctx);
ctx = NULL;
return -ENOMEM;
}
ecryptfs_init_mount_crypt_stat(&sbi->mount_crypt_stat);
fc->fs_private = ctx;
fc->s_fs_info = sbi;
fc->ops = &ecryptfs_context_ops;
return 0;
}
static struct file_system_type ecryptfs_fs_type = {
.owner = THIS_MODULE,
.name = "ecryptfs",
.mount = ecryptfs_mount,
.init_fs_context = ecryptfs_init_fs_context,
.parameters = ecryptfs_fs_param_spec,
.kill_sb = ecryptfs_kill_block_super,
.fs_flags = 0
};