mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-21 16:29:59 +00:00
![Linus Torvalds](/assets/img/avatar_default.png)
-----BEGIN PGP SIGNATURE----- iHUEABYIAB0WIQQqUNBr3gm4hGXdBJlZ7Krx/gZQ6wUCYzxmRQAKCRBZ7Krx/gZQ 6+/kAQD2xyf+i4zOYVBr1NB3qBbhVS1zrni1NbC/kT3dJPgTvwEA7z7eqwnrN4zg scKFP8a3yPoaQBfs4do5PolhuSr2ngA= =NBI+ -----END PGP SIGNATURE----- Merge tag 'pull-path' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs constification updates from Al Viro: "whack-a-mole: constifying struct path *" * tag 'pull-path' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: ecryptfs: constify path spufs: constify path nd_jump_link(): constify path audit_init_parent(): constify path __io_setxattr(): constify path do_proc_readlink(): constify path overlayfs: constify path fs/notify: constify path may_linkat(): constify path do_sys_name_to_handle(): constify path ->getprocattr(): attribute name is const char *, TYVM...
418 lines
11 KiB
C
418 lines
11 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
|
|
/*
|
|
* eCryptfs: Linux filesystem encryption layer
|
|
*
|
|
* Copyright (C) 1997-2004 Erez Zadok
|
|
* Copyright (C) 2001-2004 Stony Brook University
|
|
* Copyright (C) 2004-2007 International Business Machines Corp.
|
|
* Author(s): Michael A. Halcrow <mhalcrow@us.ibm.com>
|
|
* Michael C. Thompson <mcthomps@us.ibm.com>
|
|
*/
|
|
|
|
#include <linux/file.h>
|
|
#include <linux/poll.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/mount.h>
|
|
#include <linux/pagemap.h>
|
|
#include <linux/security.h>
|
|
#include <linux/compat.h>
|
|
#include <linux/fs_stack.h>
|
|
#include "ecryptfs_kernel.h"
|
|
|
|
/*
|
|
* ecryptfs_read_update_atime
|
|
*
|
|
* generic_file_read updates the atime of upper layer inode. But, it
|
|
* doesn't give us a chance to update the atime of the lower layer
|
|
* inode. This function is a wrapper to generic_file_read. It
|
|
* updates the atime of the lower level inode if generic_file_read
|
|
* returns without any errors. This is to be used only for file reads.
|
|
* The function to be used for directory reads is ecryptfs_read.
|
|
*/
|
|
static ssize_t ecryptfs_read_update_atime(struct kiocb *iocb,
|
|
struct iov_iter *to)
|
|
{
|
|
ssize_t rc;
|
|
const struct path *path;
|
|
struct file *file = iocb->ki_filp;
|
|
|
|
rc = generic_file_read_iter(iocb, to);
|
|
if (rc >= 0) {
|
|
path = ecryptfs_dentry_to_lower_path(file->f_path.dentry);
|
|
touch_atime(path);
|
|
}
|
|
return rc;
|
|
}
|
|
|
|
struct ecryptfs_getdents_callback {
|
|
struct dir_context ctx;
|
|
struct dir_context *caller;
|
|
struct super_block *sb;
|
|
int filldir_called;
|
|
int entries_written;
|
|
};
|
|
|
|
/* Inspired by generic filldir in fs/readdir.c */
|
|
static bool
|
|
ecryptfs_filldir(struct dir_context *ctx, const char *lower_name,
|
|
int lower_namelen, loff_t offset, u64 ino, unsigned int d_type)
|
|
{
|
|
struct ecryptfs_getdents_callback *buf =
|
|
container_of(ctx, struct ecryptfs_getdents_callback, ctx);
|
|
size_t name_size;
|
|
char *name;
|
|
int err;
|
|
bool res;
|
|
|
|
buf->filldir_called++;
|
|
err = ecryptfs_decode_and_decrypt_filename(&name, &name_size,
|
|
buf->sb, lower_name,
|
|
lower_namelen);
|
|
if (err) {
|
|
if (err != -EINVAL) {
|
|
ecryptfs_printk(KERN_DEBUG,
|
|
"%s: Error attempting to decode and decrypt filename [%s]; rc = [%d]\n",
|
|
__func__, lower_name, err);
|
|
return false;
|
|
}
|
|
|
|
/* Mask -EINVAL errors as these are most likely due a plaintext
|
|
* filename present in the lower filesystem despite filename
|
|
* encryption being enabled. One unavoidable example would be
|
|
* the "lost+found" dentry in the root directory of an Ext4
|
|
* filesystem.
|
|
*/
|
|
return true;
|
|
}
|
|
|
|
buf->caller->pos = buf->ctx.pos;
|
|
res = dir_emit(buf->caller, name, name_size, ino, d_type);
|
|
kfree(name);
|
|
if (res)
|
|
buf->entries_written++;
|
|
return res;
|
|
}
|
|
|
|
/**
|
|
* ecryptfs_readdir
|
|
* @file: The eCryptfs directory file
|
|
* @ctx: The actor to feed the entries to
|
|
*/
|
|
static int ecryptfs_readdir(struct file *file, struct dir_context *ctx)
|
|
{
|
|
int rc;
|
|
struct file *lower_file;
|
|
struct inode *inode = file_inode(file);
|
|
struct ecryptfs_getdents_callback buf = {
|
|
.ctx.actor = ecryptfs_filldir,
|
|
.caller = ctx,
|
|
.sb = inode->i_sb,
|
|
};
|
|
lower_file = ecryptfs_file_to_lower(file);
|
|
rc = iterate_dir(lower_file, &buf.ctx);
|
|
ctx->pos = buf.ctx.pos;
|
|
if (rc >= 0 && (buf.entries_written || !buf.filldir_called))
|
|
fsstack_copy_attr_atime(inode, file_inode(lower_file));
|
|
return rc;
|
|
}
|
|
|
|
struct kmem_cache *ecryptfs_file_info_cache;
|
|
|
|
static int read_or_initialize_metadata(struct dentry *dentry)
|
|
{
|
|
struct inode *inode = d_inode(dentry);
|
|
struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
|
|
struct ecryptfs_crypt_stat *crypt_stat;
|
|
int rc;
|
|
|
|
crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat;
|
|
mount_crypt_stat = &ecryptfs_superblock_to_private(
|
|
inode->i_sb)->mount_crypt_stat;
|
|
mutex_lock(&crypt_stat->cs_mutex);
|
|
|
|
if (crypt_stat->flags & ECRYPTFS_POLICY_APPLIED &&
|
|
crypt_stat->flags & ECRYPTFS_KEY_VALID) {
|
|
rc = 0;
|
|
goto out;
|
|
}
|
|
|
|
rc = ecryptfs_read_metadata(dentry);
|
|
if (!rc)
|
|
goto out;
|
|
|
|
if (mount_crypt_stat->flags & ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED) {
|
|
crypt_stat->flags &= ~(ECRYPTFS_I_SIZE_INITIALIZED
|
|
| ECRYPTFS_ENCRYPTED);
|
|
rc = 0;
|
|
goto out;
|
|
}
|
|
|
|
if (!(mount_crypt_stat->flags & ECRYPTFS_XATTR_METADATA_ENABLED) &&
|
|
!i_size_read(ecryptfs_inode_to_lower(inode))) {
|
|
rc = ecryptfs_initialize_file(dentry, inode);
|
|
if (!rc)
|
|
goto out;
|
|
}
|
|
|
|
rc = -EIO;
|
|
out:
|
|
mutex_unlock(&crypt_stat->cs_mutex);
|
|
return rc;
|
|
}
|
|
|
|
static int ecryptfs_mmap(struct file *file, struct vm_area_struct *vma)
|
|
{
|
|
struct file *lower_file = ecryptfs_file_to_lower(file);
|
|
/*
|
|
* Don't allow mmap on top of file systems that don't support it
|
|
* natively. If FILESYSTEM_MAX_STACK_DEPTH > 2 or ecryptfs
|
|
* allows recursive mounting, this will need to be extended.
|
|
*/
|
|
if (!lower_file->f_op->mmap)
|
|
return -ENODEV;
|
|
return generic_file_mmap(file, vma);
|
|
}
|
|
|
|
/**
|
|
* ecryptfs_open
|
|
* @inode: inode specifying file to open
|
|
* @file: Structure to return filled in
|
|
*
|
|
* Opens the file specified by inode.
|
|
*
|
|
* Returns zero on success; non-zero otherwise
|
|
*/
|
|
static int ecryptfs_open(struct inode *inode, struct file *file)
|
|
{
|
|
int rc = 0;
|
|
struct ecryptfs_crypt_stat *crypt_stat = NULL;
|
|
struct dentry *ecryptfs_dentry = file->f_path.dentry;
|
|
/* Private value of ecryptfs_dentry allocated in
|
|
* ecryptfs_lookup() */
|
|
struct ecryptfs_file_info *file_info;
|
|
|
|
/* Released in ecryptfs_release or end of function if failure */
|
|
file_info = kmem_cache_zalloc(ecryptfs_file_info_cache, GFP_KERNEL);
|
|
ecryptfs_set_file_private(file, file_info);
|
|
if (!file_info) {
|
|
ecryptfs_printk(KERN_ERR,
|
|
"Error attempting to allocate memory\n");
|
|
rc = -ENOMEM;
|
|
goto out;
|
|
}
|
|
crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat;
|
|
mutex_lock(&crypt_stat->cs_mutex);
|
|
if (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED)) {
|
|
ecryptfs_printk(KERN_DEBUG, "Setting flags for stat...\n");
|
|
/* Policy code enabled in future release */
|
|
crypt_stat->flags |= (ECRYPTFS_POLICY_APPLIED
|
|
| ECRYPTFS_ENCRYPTED);
|
|
}
|
|
mutex_unlock(&crypt_stat->cs_mutex);
|
|
rc = ecryptfs_get_lower_file(ecryptfs_dentry, inode);
|
|
if (rc) {
|
|
printk(KERN_ERR "%s: Error attempting to initialize "
|
|
"the lower file for the dentry with name "
|
|
"[%pd]; rc = [%d]\n", __func__,
|
|
ecryptfs_dentry, rc);
|
|
goto out_free;
|
|
}
|
|
if ((ecryptfs_inode_to_private(inode)->lower_file->f_flags & O_ACCMODE)
|
|
== O_RDONLY && (file->f_flags & O_ACCMODE) != O_RDONLY) {
|
|
rc = -EPERM;
|
|
printk(KERN_WARNING "%s: Lower file is RO; eCryptfs "
|
|
"file must hence be opened RO\n", __func__);
|
|
goto out_put;
|
|
}
|
|
ecryptfs_set_file_lower(
|
|
file, ecryptfs_inode_to_private(inode)->lower_file);
|
|
rc = read_or_initialize_metadata(ecryptfs_dentry);
|
|
if (rc)
|
|
goto out_put;
|
|
ecryptfs_printk(KERN_DEBUG, "inode w/ addr = [0x%p], i_ino = "
|
|
"[0x%.16lx] size: [0x%.16llx]\n", inode, inode->i_ino,
|
|
(unsigned long long)i_size_read(inode));
|
|
goto out;
|
|
out_put:
|
|
ecryptfs_put_lower_file(inode);
|
|
out_free:
|
|
kmem_cache_free(ecryptfs_file_info_cache,
|
|
ecryptfs_file_to_private(file));
|
|
out:
|
|
return rc;
|
|
}
|
|
|
|
/**
|
|
* ecryptfs_dir_open
|
|
* @inode: inode specifying file to open
|
|
* @file: Structure to return filled in
|
|
*
|
|
* Opens the file specified by inode.
|
|
*
|
|
* Returns zero on success; non-zero otherwise
|
|
*/
|
|
static int ecryptfs_dir_open(struct inode *inode, struct file *file)
|
|
{
|
|
struct dentry *ecryptfs_dentry = file->f_path.dentry;
|
|
/* Private value of ecryptfs_dentry allocated in
|
|
* ecryptfs_lookup() */
|
|
struct ecryptfs_file_info *file_info;
|
|
struct file *lower_file;
|
|
|
|
/* Released in ecryptfs_release or end of function if failure */
|
|
file_info = kmem_cache_zalloc(ecryptfs_file_info_cache, GFP_KERNEL);
|
|
ecryptfs_set_file_private(file, file_info);
|
|
if (unlikely(!file_info)) {
|
|
ecryptfs_printk(KERN_ERR,
|
|
"Error attempting to allocate memory\n");
|
|
return -ENOMEM;
|
|
}
|
|
lower_file = dentry_open(ecryptfs_dentry_to_lower_path(ecryptfs_dentry),
|
|
file->f_flags, current_cred());
|
|
if (IS_ERR(lower_file)) {
|
|
printk(KERN_ERR "%s: Error attempting to initialize "
|
|
"the lower file for the dentry with name "
|
|
"[%pd]; rc = [%ld]\n", __func__,
|
|
ecryptfs_dentry, PTR_ERR(lower_file));
|
|
kmem_cache_free(ecryptfs_file_info_cache, file_info);
|
|
return PTR_ERR(lower_file);
|
|
}
|
|
ecryptfs_set_file_lower(file, lower_file);
|
|
return 0;
|
|
}
|
|
|
|
static int ecryptfs_flush(struct file *file, fl_owner_t td)
|
|
{
|
|
struct file *lower_file = ecryptfs_file_to_lower(file);
|
|
|
|
if (lower_file->f_op->flush) {
|
|
filemap_write_and_wait(file->f_mapping);
|
|
return lower_file->f_op->flush(lower_file, td);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int ecryptfs_release(struct inode *inode, struct file *file)
|
|
{
|
|
ecryptfs_put_lower_file(inode);
|
|
kmem_cache_free(ecryptfs_file_info_cache,
|
|
ecryptfs_file_to_private(file));
|
|
return 0;
|
|
}
|
|
|
|
static int ecryptfs_dir_release(struct inode *inode, struct file *file)
|
|
{
|
|
fput(ecryptfs_file_to_lower(file));
|
|
kmem_cache_free(ecryptfs_file_info_cache,
|
|
ecryptfs_file_to_private(file));
|
|
return 0;
|
|
}
|
|
|
|
static loff_t ecryptfs_dir_llseek(struct file *file, loff_t offset, int whence)
|
|
{
|
|
return vfs_llseek(ecryptfs_file_to_lower(file), offset, whence);
|
|
}
|
|
|
|
static int
|
|
ecryptfs_fsync(struct file *file, loff_t start, loff_t end, int datasync)
|
|
{
|
|
int rc;
|
|
|
|
rc = file_write_and_wait(file);
|
|
if (rc)
|
|
return rc;
|
|
|
|
return vfs_fsync(ecryptfs_file_to_lower(file), datasync);
|
|
}
|
|
|
|
static int ecryptfs_fasync(int fd, struct file *file, int flag)
|
|
{
|
|
int rc = 0;
|
|
struct file *lower_file = NULL;
|
|
|
|
lower_file = ecryptfs_file_to_lower(file);
|
|
if (lower_file->f_op->fasync)
|
|
rc = lower_file->f_op->fasync(fd, lower_file, flag);
|
|
return rc;
|
|
}
|
|
|
|
static long
|
|
ecryptfs_unlocked_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
|
|
{
|
|
struct file *lower_file = ecryptfs_file_to_lower(file);
|
|
long rc = -ENOTTY;
|
|
|
|
if (!lower_file->f_op->unlocked_ioctl)
|
|
return rc;
|
|
|
|
switch (cmd) {
|
|
case FITRIM:
|
|
case FS_IOC_GETFLAGS:
|
|
case FS_IOC_SETFLAGS:
|
|
case FS_IOC_GETVERSION:
|
|
case FS_IOC_SETVERSION:
|
|
rc = lower_file->f_op->unlocked_ioctl(lower_file, cmd, arg);
|
|
fsstack_copy_attr_all(file_inode(file), file_inode(lower_file));
|
|
|
|
return rc;
|
|
default:
|
|
return rc;
|
|
}
|
|
}
|
|
|
|
#ifdef CONFIG_COMPAT
|
|
static long
|
|
ecryptfs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
|
|
{
|
|
struct file *lower_file = ecryptfs_file_to_lower(file);
|
|
long rc = -ENOIOCTLCMD;
|
|
|
|
if (!lower_file->f_op->compat_ioctl)
|
|
return rc;
|
|
|
|
switch (cmd) {
|
|
case FITRIM:
|
|
case FS_IOC32_GETFLAGS:
|
|
case FS_IOC32_SETFLAGS:
|
|
case FS_IOC32_GETVERSION:
|
|
case FS_IOC32_SETVERSION:
|
|
rc = lower_file->f_op->compat_ioctl(lower_file, cmd, arg);
|
|
fsstack_copy_attr_all(file_inode(file), file_inode(lower_file));
|
|
|
|
return rc;
|
|
default:
|
|
return rc;
|
|
}
|
|
}
|
|
#endif
|
|
|
|
const struct file_operations ecryptfs_dir_fops = {
|
|
.iterate_shared = ecryptfs_readdir,
|
|
.read = generic_read_dir,
|
|
.unlocked_ioctl = ecryptfs_unlocked_ioctl,
|
|
#ifdef CONFIG_COMPAT
|
|
.compat_ioctl = ecryptfs_compat_ioctl,
|
|
#endif
|
|
.open = ecryptfs_dir_open,
|
|
.release = ecryptfs_dir_release,
|
|
.fsync = ecryptfs_fsync,
|
|
.llseek = ecryptfs_dir_llseek,
|
|
};
|
|
|
|
const struct file_operations ecryptfs_main_fops = {
|
|
.llseek = generic_file_llseek,
|
|
.read_iter = ecryptfs_read_update_atime,
|
|
.write_iter = generic_file_write_iter,
|
|
.unlocked_ioctl = ecryptfs_unlocked_ioctl,
|
|
#ifdef CONFIG_COMPAT
|
|
.compat_ioctl = ecryptfs_compat_ioctl,
|
|
#endif
|
|
.mmap = ecryptfs_mmap,
|
|
.open = ecryptfs_open,
|
|
.flush = ecryptfs_flush,
|
|
.release = ecryptfs_release,
|
|
.fsync = ecryptfs_fsync,
|
|
.fasync = ecryptfs_fasync,
|
|
.splice_read = generic_file_splice_read,
|
|
};
|