Commit Graph

21 Commits

Author SHA1 Message Date
David Gstir 6a34e4d2be fscrypt: Rename FS_WRITE_PATH_FL to FS_CTX_HAS_BOUNCE_BUFFER_FL
... to better explain its purpose after introducing in-place encryption
without bounce buffer.

Signed-off-by: David Gstir <david@sigma-star.at>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-12-11 16:33:18 -05:00
David Gstir f32d7ac20a fscrypt: Delay bounce page pool allocation until needed
Since fscrypt users can now indicated if fscrypt_encrypt_page() should
use a bounce page, we can delay the bounce page pool initialization util
it is really needed. That is until fscrypt_operations has no
FS_CFLG_OWN_PAGES flag set.

Signed-off-by: David Gstir <david@sigma-star.at>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-12-11 16:33:11 -05:00
David Gstir bd7b829038 fscrypt: Cleanup page locking requirements for fscrypt_{decrypt,encrypt}_page()
Rename the FS_CFLG_INPLACE_ENCRYPTION flag to FS_CFLG_OWN_PAGES which,
when set, indicates that the fs uses pages under its own control as
opposed to writeback pages which require locking and a bounce buffer for
encryption.

Signed-off-by: David Gstir <david@sigma-star.at>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-12-11 16:26:12 -05:00
David Gstir 1400451f04 fscrypt: Cleanup fscrypt_{decrypt,encrypt}_page()
- Improve documentation
- Add BUG_ON(len == 0) to avoid accidental switch of offs and len
parameters
- Improve variable names for readability

Signed-off-by: David Gstir <david@sigma-star.at>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-12-11 16:26:12 -05:00
Theodore Ts'o 41d5319af3 fscrypt: move the policy flags and encryption mode definitions to uapi header
These constants are part of the UAPI, so they belong in
include/uapi/linux/fs.h instead of include/linux/fscrypto.h

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Eric Biggers <ebiggers@google.com>
2016-12-11 16:26:10 -05:00
Theodore Ts'o cc4e0df038 fscrypt: move non-public structures and constants to fscrypt_private.h
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Eric Biggers <ebiggers@google.com>
2016-12-11 16:26:09 -05:00
Theodore Ts'o b98701df34 fscrypt: unexport fscrypt_initialize()
The fscrypt_initalize() function isn't used outside fs/crypto, so
there's no point making it be an exported symbol.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Eric Biggers <ebiggers@google.com>
2016-12-11 16:26:08 -05:00
Theodore Ts'o 3325bea5b2 fscrypt: rename get_crypt_info() to fscrypt_get_crypt_info()
To avoid namespace collisions, rename get_crypt_info() to
fscrypt_get_crypt_info().  The function is only used inside the
fs/crypto directory, so declare it in the new header file,
fscrypt_private.h.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Eric Biggers <ebiggers@google.com>
2016-12-11 16:26:08 -05:00
Eric Biggers db717d8e26 fscrypto: move ioctl processing more fully into common code
Multiple bugs were recently fixed in the "set encryption policy" ioctl.
To make it clear that fscrypt_process_policy() and fscrypt_get_policy()
implement ioctls and therefore their implementations must take standard
security and correctness precautions, rename them to
fscrypt_ioctl_set_policy() and fscrypt_ioctl_get_policy().  Make the
latter take in a struct file * to make it consistent with the former.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-12-11 16:26:07 -05:00
David Gstir 9c4bb8a3a9 fscrypt: Let fs select encryption index/tweak
Avoid re-use of page index as tweak for AES-XTS when multiple parts of
same page are encrypted. This will happen on multiple (partial) calls of
fscrypt_encrypt_page on same page.
page->index is only valid for writeback pages.

Signed-off-by: David Gstir <david@sigma-star.at>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-11-13 20:18:16 -05:00
David Gstir 0b93e1b94b fscrypt: Constify struct inode pointer
Some filesystems, such as UBIFS, maintain a const pointer for struct
inode.

Signed-off-by: David Gstir <david@sigma-star.at>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-11-13 20:18:01 -05:00
David Gstir 7821d4dd45 fscrypt: Enable partial page encryption
Not all filesystems work on full pages, thus we should allow them to
hand partial pages to fscrypt for en/decryption.

Signed-off-by: David Gstir <david@sigma-star.at>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-11-13 18:55:21 -05:00
David Gstir b50f7b268b fscrypt: Allow fscrypt_decrypt_page() to function with non-writeback pages
Some filesystem might pass pages which do not have page->mapping->host
set to the encrypted inode. We want the caller to explicitly pass the
corresponding inode.

Signed-off-by: David Gstir <david@sigma-star.at>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-11-13 18:53:10 -05:00
David Gstir 1c7dcf69ee fscrypt: Add in-place encryption mode
ext4 and f2fs require a bounce page when encrypting pages. However, not
all filesystems will need that (eg. UBIFS). This is handled via a
flag on fscrypt_operations where a fs implementation can select in-place
encryption over using a bounce page (which is the default).

Signed-off-by: David Gstir <david@sigma-star.at>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-11-13 18:47:04 -05:00
Linus Torvalds 2eee010d09 Lots of bug fixes and cleanups.
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Merge tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

Pull ext4 updates from Ted Ts'o:
 "Lots of bug fixes and cleanups"

* tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (40 commits)
  ext4: remove unused variable
  ext4: use journal inode to determine journal overhead
  ext4: create function to read journal inode
  ext4: unmap metadata when zeroing blocks
  ext4: remove plugging from ext4_file_write_iter()
  ext4: allow unlocked direct IO when pages are cached
  ext4: require encryption feature for EXT4_IOC_SET_ENCRYPTION_POLICY
  fscrypto: use standard macros to compute length of fname ciphertext
  ext4: do not unnecessarily null-terminate encrypted symlink data
  ext4: release bh in make_indexed_dir
  ext4: Allow parallel DIO reads
  ext4: allow DAX writeback for hole punch
  jbd2: fix lockdep annotation in add_transaction_credits()
  blockgroup_lock.h: simplify definition of NR_BG_LOCKS
  blockgroup_lock.h: remove debris from bgl_lock_ptr() conversion
  fscrypto: make filename crypto functions return 0 on success
  fscrypto: rename completion callbacks to reflect usage
  fscrypto: remove unnecessary includes
  fscrypto: improved validation when loading inode encryption metadata
  ext4: fix memory leak when symlink decryption fails
  ...
2016-10-07 15:15:33 -07:00
Eric Biggers 8f39850dff fscrypto: improved validation when loading inode encryption metadata
- Validate fscrypt_context.format and fscrypt_context.flags.  If
  unrecognized values are set, then the kernel may not know how to
  interpret the encrypted file, so it should fail the operation.

- Validate that AES_256_XTS is used for contents and that AES_256_CTS is
  used for filenames.  It was previously possible for the kernel to
  accept these reversed, though it would have taken manual editing of
  the block device.  This was not intended.

- Fail cleanly rather than BUG()-ing if a file has an unexpected type.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-09-15 13:32:11 -04:00
Eric Biggers ba63f23d69 fscrypto: require write access to mount to set encryption policy
Since setting an encryption policy requires writing metadata to the
filesystem, it should be guarded by mnt_want_write/mnt_drop_write.
Otherwise, a user could cause a write to a frozen or readonly
filesystem.  This was handled correctly by f2fs but not by ext4.  Make
fscrypt_process_policy() handle it rather than relying on the filesystem
to get it right.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Cc: stable@vger.kernel.org # 4.1+; check fs/{ext4,f2fs}
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Acked-by: Jaegeuk Kim <jaegeuk@kernel.org>
2016-09-10 01:18:57 -04:00
Jaegeuk Kim b5a7aef1ef fscrypto/f2fs: allow fs-specific key prefix for fs encryption
This patch allows fscrypto to handle a second key prefix given by filesystem.
The main reason is to provide backward compatibility, since previously f2fs
used "f2fs:" as a crypto prefix instead of "fscrypt:".
Later, ext4 should also provide key_prefix() to give "ext4:".

One concern decribed by Ted would be kinda double check overhead of prefixes.
In x86, for example, validate_user_key consumes 8 ms after boot-up, which turns
out derive_key_aes() consumed most of the time to load specific crypto module.
After such the cold miss, it shows almost zero latencies, which treats as a
negligible overhead.
Note that request_key() detects wrong prefix in prior to derive_key_aes() even.

Cc: Ted Tso <tytso@mit.edu>
Cc: stable@vger.kernel.org # v4.6
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2016-05-07 10:32:33 -07:00
Jaegeuk Kim b32e4482aa fscrypto: don't let data integrity writebacks fail with ENOMEM
This patch fixes the issue introduced by the ext4 crypto fix in a same manner.
For F2FS, however, we flush the pending IOs and wait for a while to acquire free
memory.

Fixes: c9af28fdd4 ("ext4 crypto: don't let data integrity writebacks fail with ENOMEM")
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2016-04-12 10:25:30 -07:00
Linus Torvalds d407574e79 Merge tag 'for-f2fs-4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs
Pull f2fs updates from Jaegeuk Kim:
 "New Features:
   - uplift filesystem encryption into fs/crypto/
   - give sysfs entries to control memroy consumption

  Enhancements:
   - aio performance by preallocating blocks in ->write_iter
   - use writepages lock for only WB_SYNC_ALL
   - avoid redundant inline_data conversion
   - enhance forground GC
   - use wait_for_stable_page as possible
   - speed up SEEK_DATA and fiiemap

  Bug Fixes:
   - corner case in terms of -ENOSPC for inline_data
   - hung task caused by long latency in shrinker
   - corruption between atomic write and f2fs_trace_pid
   - avoid garbage lengths in dentries
   - revoke atomicly written pages if an error occurs

  In addition, there are various minor bug fixes and clean-ups"

* tag 'for-f2fs-4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs: (81 commits)
  f2fs: submit node page write bios when really required
  f2fs: add missing argument to f2fs_setxattr stub
  f2fs: fix to avoid unneeded unlock_new_inode
  f2fs: clean up opened code with f2fs_update_dentry
  f2fs: declare static functions
  f2fs: use cryptoapi crc32 functions
  f2fs: modify the readahead method in ra_node_page()
  f2fs crypto: sync ext4_lookup and ext4_file_open
  fs crypto: move per-file encryption from f2fs tree to fs/crypto
  f2fs: mutex can't be used by down_write_nest_lock()
  f2fs: recovery missing dot dentries in root directory
  f2fs: fix to avoid deadlock when merging inline data
  f2fs: introduce f2fs_flush_merged_bios for cleanup
  f2fs: introduce f2fs_update_data_blkaddr for cleanup
  f2fs crypto: fix incorrect positioning for GCing encrypted data page
  f2fs: fix incorrect upper bound when iterating inode mapping tree
  f2fs: avoid hungtask problem caused by losing wake_up
  f2fs: trace old block address for CoWed page
  f2fs: try to flush inode after merging inline data
  f2fs: show more info about superblock recovery
  ...
2016-03-21 11:03:02 -07:00
Jaegeuk Kim 0b81d07790 fs crypto: move per-file encryption from f2fs tree to fs/crypto
This patch adds the renamed functions moved from the f2fs crypto files.

1. definitions for per-file encryption used by ext4 and f2fs.

2. crypto.c for encrypt/decrypt functions
 a. IO preparation:
  - fscrypt_get_ctx / fscrypt_release_ctx
 b. before IOs:
  - fscrypt_encrypt_page
  - fscrypt_decrypt_page
  - fscrypt_zeroout_range
 c. after IOs:
  - fscrypt_decrypt_bio_pages
  - fscrypt_pullback_bio_page
  - fscrypt_restore_control_page

3. policy.c supporting context management.
 a. For ioctls:
  - fscrypt_process_policy
  - fscrypt_get_policy
 b. For context permission
  - fscrypt_has_permitted_context
  - fscrypt_inherit_context

4. keyinfo.c to handle permissions
  - fscrypt_get_encryption_info
  - fscrypt_free_encryption_info

5. fname.c to support filename encryption
 a. general wrapper functions
  - fscrypt_fname_disk_to_usr
  - fscrypt_fname_usr_to_disk
  - fscrypt_setup_filename
  - fscrypt_free_filename

 b. specific filename handling functions
  - fscrypt_fname_alloc_buffer
  - fscrypt_fname_free_buffer

6. Makefile and Kconfig

Cc: Al Viro <viro@ftp.linux.org.uk>
Signed-off-by: Michael Halcrow <mhalcrow@google.com>
Signed-off-by: Ildar Muslukhov <ildarm@google.com>
Signed-off-by: Uday Savagaonkar <savagaon@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2016-03-17 21:19:33 -07:00