eCryptfs uses MD5 for a couple unusual purposes: to "mix" the key into
the IVs for file contents encryption (similar to ESSIV), and to prepend
some key-dependent bytes to the plaintext when encrypting filenames
(which is useless since eCryptfs encrypts the filenames with ECB).
Currently, eCryptfs computes these MD5 hashes using the crypto_shash
API. Update it to instead use the MD5 library API. This is simpler and
faster: the library doesn't require memory allocations, can't fail, and
provides direct access to MD5 without overhead such as indirect calls.
To preserve the existing behavior of eCryptfs support being disabled
when the kernel is booted with "fips=1", make ecryptfs_get_tree() check
fips_enabled itself. Previously it relied on crypto_alloc_shash("md5")
failing. I don't know for sure that this is actually needed; e.g., it
could be argued that eCryptfs's use of MD5 isn't for a security purpose
as far as FIPS is concerned. But this preserves the existing behavior.
Tested by verifying that an existing eCryptfs can still be mounted with
a kernel that has this commit, with all the files matching. Also tested
creating a filesystem with this commit and mounting+reading it without.
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
Link: https://patch.msgid.link/20251011200010.193140-1-ebiggers@kernel.org
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Fixes the following W=1 kernel build warning(s):
fs/ecryptfs/super.c:22: warning: cannot understand function prototype: 'struct kmem_cache *ecryptfs_inode_info_cache; '
fs/ecryptfs/super.c:91: warning: Function parameter or member 'dentry' not described in 'ecryptfs_statfs'
fs/ecryptfs/super.c:91: warning: Excess function parameter 'sb' description in 'ecryptfs_statfs'
fs/ecryptfs/super.c:120: warning: Function parameter or member 'inode' not described in 'ecryptfs_evict_inode'
fs/ecryptfs/super.c:133: warning: Function parameter or member 'm' not described in 'ecryptfs_show_options'
fs/ecryptfs/super.c:133: warning: Function parameter or member 'root' not described in 'ecryptfs_show_options'
Cc: Tyler Hicks <code@tyhicks.com>
Cc: "Michael A. Halcrow" <mahalcro@us.ibm.com>
Cc: "Michael C. Thompson" <mcthomps@us.ibm.com>
Cc: ecryptfs@vger.kernel.org
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Tyler Hicks <code@tyhicks.com>
Based on 1 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version this program is distributed in the
hope that it will be useful but without any warranty without even
the implied warranty of merchantability or fitness for a particular
purpose see the gnu general public license for more details you
should have received a copy of the gnu general public license along
with this program if not write to the free software foundation inc
59 temple place suite 330 boston ma 02111 1307 usa
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-or-later
has been chosen to replace the boilerplate/reference in 1334 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070033.113240726@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
You cannot allocate crypto tfm objects in NORECLAIM or NOFS contexts.
The ecryptfs code currently does exactly that for the MD5 tfm.
This patch fixes it by preallocating the MD5 tfm in a safe context.
The MD5 tfm is also reentrant so this patch removes the superfluous
cs_hash_tfm_mutex.
Reported-by: Nicolas Boichat <drinkcat@chromium.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This patch replaces uses of ablkcipher and blkcipher with skcipher,
and the long obsolete hash interface with shash.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
After we moved inode_sync_wait() from end_writeback() it doesn't make sense
to call the function end_writeback() anymore. Rename it to clear_inode()
which well says what the function really does - set I_CLEAR flag.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
statfs() calls on eCryptfs files returned the wrong filesystem type and,
when using filename encryption, the wrong maximum filename length.
If mount-wide filename encryption is enabled, the cipher block size and
the lower filesystem's max filename length will determine the max
eCryptfs filename length. Pre-tested, known good lengths are used when
the lower filesystem's namelen is 255 and a cipher with 8 or 16 byte
block sizes is used. In other, less common cases, we fall back to a safe
rounded-down estimate when determining the eCryptfs namelen.
https://launchpad.net/bugs/885744
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Reported-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: John Johansen <john.johansen@canonical.com>
Seeing that just about every destructor got that INIT_LIST_HEAD() copied into
it, there is no point whatsoever keeping this INIT_LIST_HEAD in inode_init_once();
the cost of taking it into inode_init_always() will be negligible for pipes
and sockets and negative for everything else. Not to mention the removal of
boilerplate code from ->destroy_inode() instances...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
These functions should live in inode.c since their focus is on inodes
and they're primarily used by functions in inode.c.
Also does a simple cleanup of ecryptfs_inode_test() and rolls
ecryptfs_init_inode() into ecryptfs_inode_set().
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
Tested-by: David <david@unsolicited.net>
For any given lower inode, eCryptfs keeps only one lower file open and
multiplexes all eCryptfs file operations through that lower file. The
lower file was considered "persistent" and stayed open from the first
lookup through the lifetime of the inode.
This patch keeps the notion of a single, per-inode lower file, but adds
reference counting around the lower file so that it is closed when not
currently in use. If the reference count is at 0 when an operation (such
as open, create, etc.) needs to use the lower file, a new lower file is
opened. Since the file is no longer persistent, all references to the
term persistent file are changed to lower file.
Locking is added around the sections of code that opens the lower file
and assign the pointer in the inode info, as well as the code the fputs
the lower file when all eCryptfs users are done with it.
This patch is needed to fix issues, when mounted on top of the NFSv3
client, where the lower file is left silly renamed until the eCryptfs
inode is destroyed.
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
Change the write path to encrypt the data only when the page is written to
disk in ecryptfs_writepage. Previously, ecryptfs encrypts the page in
ecryptfs_write_end which means that if there are multiple write requests to
the same page, ecryptfs ends up re-encrypting that page over and over again.
This patch minimizes the number of encryptions needed.
Signed-off-by: Thieu Le <thieule@chromium.org>
[tyhicks: Changed NULL .drop_inode sop pointer to generic_drop_inode]
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
RCU free the struct inode. This will allow:
- Subsequent store-free path walking patch. The inode must be consulted for
permissions when walking, so an RCU inode reference is a must.
- sb_inode_list_lock to be moved inside i_lock because sb list walkers who want
to take i_lock no longer need to take sb_inode_list_lock to walk the list in
the first place. This will simplify and optimize locking.
- Could remove some nested trylock loops in dcache code
- Could potentially simplify things a bit in VM land. Do not need to take the
page lock to follow page->mapping.
The downsides of this is the performance cost of using RCU. In a simple
creat/unlink microbenchmark, performance drops by about 10% due to inability to
reuse cache-hot slab objects. As iterations increase and RCU freeing starts
kicking over, this increases to about 20%.
In cases where inode lifetimes are longer (ie. many inodes may be allocated
during the average life span of a single inode), a lot of this cache reuse is
not applicable, so the regression caused by this patch is smaller.
The cache-hot regression could largely be avoided by using SLAB_DESTROY_BY_RCU,
however this adds some complexity to list walking and store-free path walking,
so I prefer to implement this at a later date, if it is shown to be a win in
real situations. I haven't found a regression in any non-micro benchmark so I
doubt it will be a problem.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
The big kernel lock has been removed from all these files at some point,
leaving only the #include.
Remove this too as a cleanup.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We'll need the path to implement the flags field for statvfs support.
We do have it available in all callers except:
- ecryptfs_statfs. This one doesn't actually need vfs_statfs but just
needs to do a caller to the lower filesystem statfs method.
- sys_ustat. Add a non-exported statfs_by_dentry helper for it which
doesn't won't be able to fill out the flags field later on.
In addition rename the helpers for statfs vs fstatfs to do_*statfs instead
of the misleading vfs prefix.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
First of all, get_sb_nodev() grabs anon dev minor and we
never free it in ecryptfs ->kill_sb(). Moreover, on one
of the failure exits in ecryptfs_get_sb() we leak things -
it happens before we set ->s_root and ->put_super() won't
be called in that case. Solution: kill ->put_super(), do
all that stuff in ->kill_sb(). And use kill_anon_sb() instead
of generic_shutdown_super() to deal with anon dev leak.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ecryptfs/ecryptfs-2.6:
eCryptfs: Turn lower lookup error messages into debug messages
eCryptfs: Copy lower directory inode times and size on link
ecryptfs: fix use with tmpfs by removing d_drop from ecryptfs_destroy_inode
ecryptfs: fix error code for missing xattrs in lower fs
eCryptfs: Decrypt symlink target for stat size
eCryptfs: Strip metadata in xattr flag in encrypted view
eCryptfs: Clear buffer before reading in metadata xattr
eCryptfs: Rename ecryptfs_crypt_stat.num_header_bytes_at_front
eCryptfs: Fix metadata in xattr feature regression
Eric BiggersandChristian Brauner
Eric SandeenandChristian Brauner
Muchun SongandLinus Torvalds
Lee JonesandTyler Hicks
Thomas GleixnerandGreg Kroah-Hartman
Al Viro
Herbert Xu
Johannes WeinerandLinus Torvalds
Jan KaraandFengguang Wu
Tyler Hicks
Tyler Hicks
Thieu LeandTyler Hicks
Nick Piggin
Arnd BergmannandLinus Torvalds
Christoph HellwigandAl Viro
Jens Axboe