rcu_dereference_key() and user_key_payload() are currently being used in
two different, incompatible ways:
(1) As a wrapper to rcu_dereference() - when only the RCU read lock used
to protect the key.
(2) As a wrapper to rcu_dereference_protected() - when the key semaphor is
used to protect the key and the may be being modified.
Fix this by splitting both of the key wrappers to produce:
(1) RCU accessors for keys when caller has the key semaphore locked:
dereference_key_locked()
user_key_payload_locked()
(2) RCU accessors for keys when caller holds the RCU read lock:
dereference_key_rcu()
user_key_payload_rcu()
This should fix following warning in the NFS idmapper
===============================
[ INFO: suspicious RCU usage. ]
4.10.0 #1 Tainted: G W
-------------------------------
./include/keys/user-type.h:53 suspicious rcu_dereference_protected() usage!
other info that might help us debug this:
rcu_scheduler_active = 2, debug_locks = 0
1 lock held by mount.nfs/5987:
#0: (rcu_read_lock){......}, at: [<d000000002527abc>] nfs_idmap_get_key+0x15c/0x420 [nfsv4]
stack backtrace:
CPU: 1 PID: 5987 Comm: mount.nfs Tainted: G W 4.10.0 #1
Call Trace:
dump_stack+0xe8/0x154 (unreliable)
lockdep_rcu_suspicious+0x140/0x190
nfs_idmap_get_key+0x380/0x420 [nfsv4]
nfs_map_name_to_uid+0x2a0/0x3b0 [nfsv4]
decode_getfattr_attrs+0xfac/0x16b0 [nfsv4]
decode_getfattr_generic.constprop.106+0xbc/0x150 [nfsv4]
nfs4_xdr_dec_lookup_root+0xac/0xb0 [nfsv4]
rpcauth_unwrap_resp+0xe8/0x140 [sunrpc]
call_decode+0x29c/0x910 [sunrpc]
__rpc_execute+0x140/0x8f0 [sunrpc]
rpc_run_task+0x170/0x200 [sunrpc]
nfs4_call_sync_sequence+0x68/0xa0 [nfsv4]
_nfs4_lookup_root.isra.44+0xd0/0xf0 [nfsv4]
nfs4_lookup_root+0xe0/0x350 [nfsv4]
nfs4_lookup_root_sec+0x70/0xa0 [nfsv4]
nfs4_find_root_sec+0xc4/0x100 [nfsv4]
nfs4_proc_get_rootfh+0x5c/0xf0 [nfsv4]
nfs4_get_rootfh+0x6c/0x190 [nfsv4]
nfs4_server_common_setup+0xc4/0x260 [nfsv4]
nfs4_create_server+0x278/0x3c0 [nfsv4]
nfs4_remote_mount+0x50/0xb0 [nfsv4]
mount_fs+0x74/0x210
vfs_kern_mount+0x78/0x220
nfs_do_root_mount+0xb0/0x140 [nfsv4]
nfs4_try_mount+0x60/0x100 [nfsv4]
nfs_fs_mount+0x5ec/0xda0 [nfs]
mount_fs+0x74/0x210
vfs_kern_mount+0x78/0x220
do_mount+0x254/0xf70
SyS_mount+0x94/0x100
system_call+0x38/0xe0
Reported-by: Jan Stancek <jstancek@redhat.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Jan Stancek <jstancek@redhat.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
smack ->d_instantiate() uses ->setxattr(), so to be able to call it before
we'd hashed the new dentry and attached it to inode, we need ->setxattr()
instances getting the inode as an explicit argument rather than obtaining
it from dentry.
Similar change for ->getxattr() had been done in commit ce23e64. Unlike
->getxattr() (which is used by both selinux and smack instances of
->d_instantiate()) ->setxattr() is used only by smack one and unfortunately
it got missed back then.
Reported-by: Seung-Woo Kim <sw0312.kim@samsung.com>
Tested-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Pull parallel filesystem directory handling update from Al Viro.
This is the main parallel directory work by Al that makes the vfs layer
able to do lookup and readdir in parallel within a single directory.
That's a big change, since this used to be all protected by the
directory inode mutex.
The inode mutex is replaced by an rwsem, and serialization of lookups of
a single name is done by a "in-progress" dentry marker.
The series begins with xattr cleanups, and then ends with switching
filesystems over to actually doing the readdir in parallel (switching to
the "iterate_shared()" that only takes the read lock).
A more detailed explanation of the process from Al Viro:
"The xattr work starts with some acl fixes, then switches ->getxattr to
passing inode and dentry separately. This is the point where the
things start to get tricky - that got merged into the very beginning
of the -rc3-based #work.lookups, to allow untangling the
security_d_instantiate() mess. The xattr work itself proceeds to
switch a lot of filesystems to generic_...xattr(); no complications
there.
After that initial xattr work, the series then does the following:
- untangle security_d_instantiate()
- convert a bunch of open-coded lookup_one_len_unlocked() to calls of
that thing; one such place (in overlayfs) actually yields a trivial
conflict with overlayfs fixes later in the cycle - overlayfs ended
up switching to a variant of lookup_one_len_unlocked() sans the
permission checks. I would've dropped that commit (it gets
overridden on merge from #ovl-fixes in #for-next; proper resolution
is to use the variant in mainline fs/overlayfs/super.c), but I
didn't want to rebase the damn thing - it was fairly late in the
cycle...
- some filesystems had managed to depend on lookup/lookup exclusion
for *fs-internal* data structures in a way that would break if we
relaxed the VFS exclusion. Fixing hadn't been hard, fortunately.
- core of that series - parallel lookup machinery, replacing
->i_mutex with rwsem, making lookup_slow() take it only shared. At
that point lookups happen in parallel; lookups on the same name
wait for the in-progress one to be done with that dentry.
Surprisingly little code, at that - almost all of it is in
fs/dcache.c, with fs/namei.c changes limited to lookup_slow() -
making it use the new primitive and actually switching to locking
shared.
- parallel readdir stuff - first of all, we provide the exclusion on
per-struct file basis, same as we do for read() vs lseek() for
regular files. That takes care of most of the needed exclusion in
readdir/readdir; however, these guys are trickier than lookups, so
I went for switching them one-by-one. To do that, a new method
'->iterate_shared()' is added and filesystems are switched to it
as they are either confirmed to be OK with shared lock on directory
or fixed to be OK with that. I hope to kill the original method
come next cycle (almost all in-tree filesystems are switched
already), but it's still not quite finished.
- several filesystems get switched to parallel readdir. The
interesting part here is dealing with dcache preseeding by readdir;
that needs minor adjustment to be safe with directory locked only
shared.
Most of the filesystems doing that got switched to in those
commits. Important exception: NFS. Turns out that NFS folks, with
their, er, insistence on VFS getting the fuck out of the way of the
Smart Filesystem Code That Knows How And What To Lock(tm) have
grown the locking of their own. They had their own homegrown
rwsem, with lookup/readdir/atomic_open being *writers* (sillyunlink
is the reader there). Of course, with VFS getting the fuck out of
the way, as requested, the actual smarts of the smart filesystem
code etc. had become exposed...
- do_last/lookup_open/atomic_open cleanups. As the result, open()
without O_CREAT locks the directory only shared. Including the
->atomic_open() case. Backmerge from #for-linus in the middle of
that - atomic_open() fix got brought in.
- then comes NFS switch to saner (VFS-based ;-) locking, killing the
homegrown "lookup and readdir are writers" kinda-sorta rwsem. All
exclusion for sillyunlink/lookup is done by the parallel lookups
mechanism. Exclusion between sillyunlink and rmdir is a real rwsem
now - rmdir being the writer.
Result: NFS lookups/readdirs/O_CREAT-less opens happen in parallel
now.
- the rest of the series consists of switching a lot of filesystems
to parallel readdir; in a lot of cases ->llseek() gets simplified
as well. One backmerge in there (again, #for-linus - rockridge
fix)"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (74 commits)
ext4: switch to ->iterate_shared()
hfs: switch to ->iterate_shared()
hfsplus: switch to ->iterate_shared()
hostfs: switch to ->iterate_shared()
hpfs: switch to ->iterate_shared()
hpfs: handle allocation failures in hpfs_add_pos()
gfs2: switch to ->iterate_shared()
f2fs: switch to ->iterate_shared()
afs: switch to ->iterate_shared()
befs: switch to ->iterate_shared()
befs: constify stuff a bit
isofs: switch to ->iterate_shared()
get_acorn_filename(): deobfuscate a bit
btrfs: switch to ->iterate_shared()
logfs: no need to lock directory in lseek
switch ecryptfs to ->iterate_shared
9p: switch to ->iterate_shared()
fat: switch to ->iterate_shared()
romfs, squashfs: switch to ->iterate_shared()
more trivial ->iterate_shared conversions
...
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>
Pull vfs updates from Al Viro:
- Preparations of parallel lookups (the remaining main obstacle is the
need to move security_d_instantiate(); once that becomes safe, the
rest will be a matter of rather short series local to fs/*.c
- preadv2/pwritev2 series from Christoph
- assorted fixes
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (32 commits)
splice: handle zero nr_pages in splice_to_pipe()
vfs: show_vfsstat: do not ignore errors from show_devname method
dcache.c: new helper: __d_add()
don't bother with __d_instantiate(dentry, NULL)
untangle fsnotify_d_instantiate() a bit
uninline d_add()
replace d_add_unique() with saner primitive
quota: use lookup_one_len_unlocked()
cifs_get_root(): use lookup_one_len_unlocked()
nfs_lookup: don't bother with d_instantiate(dentry, NULL)
kill dentry_unhash()
ceph_fill_trace(): don't bother with d_instantiate(dn, NULL)
autofs4: don't bother with d_instantiate(dentry, NULL) in ->lookup()
configfs: move d_rehash() into configfs_create() for regular files
ceph: don't bother with d_rehash() in splice_dentry()
namei: teach lookup_slow() to skip revalidate
namei: massage lookup_slow() to be usable by lookup_one_len_unlocked()
lookup_one_len_unlocked(): use lookup_dcache()
namei: simplify invalidation logics in lookup_dcache()
namei: change calling conventions for lookup_{fast,slow} and follow_managed()
...
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>
The patch 237fead61998: "[PATCH] ecryptfs: fs/Makefile and
fs/Kconfig" from Oct 4, 2006, leads to the following static checker
warning:
fs/ecryptfs/crypto.c:846 ecryptfs_new_file_context()
error: off-by-one overflow 'crypt_stat->cipher' size 32. rl = '0-32'
There is a mismatch between the size of ecryptfs_crypt_stat.cipher
and ecryptfs_mount_crypt_stat.global_default_cipher_name causing the
copy of the cipher name to cause a off-by-one string copy error. This
fix ensures the space reserved for this string is the same size including
the trailing zero at the end throughout ecryptfs.
This fix avoids increasing the size of ecryptfs_crypt_stat.cipher
and also ecryptfs_parse_tag_70_packet_silly_stack.cipher_string and instead
reduces the of ECRYPTFS_MAX_CIPHER_NAME_SIZE to 31 and includes the + 1 for
the end of string terminator.
NOTE: An overflow is not possible in practice since the value copied
into global_default_cipher_name is validated by
ecryptfs_code_for_cipher_string() at mount time. None of the allowed
cipher strings are long enough to cause the potential buffer overflow
fixed by this patch.
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
[tyhicks: Added the NOTE about the overflow not being triggerable]
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
If the underlying dentry doesn't have ->d_revalidate(), there's no need to
force dropping out of RCU mode. All we need for that is to make freeing
ecryptfs_dentry_info RCU-delayed.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Make the switch from the blkcipher kernel crypto interface to the
ablkcipher interface.
encrypt_scatterlist() and decrypt_scatterlist() now use the ablkcipher
interface but, from the eCryptfs standpoint, still treat the crypto
operation as a synchronous operation. They submit the async request and
then wait until the operation is finished before they return. Most of
the changes are contained inside those two functions.
Despite waiting for the completion of the crypto operation, the
ablkcipher interface provides performance increases in most cases when
used on AES-NI capable hardware.
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Acked-by: Colin King <colin.king@canonical.com>
Reviewed-by: Zeev Zilberman <zeev@annapurnaLabs.com>
Cc: Dustin Kirkland <dustin.kirkland@gazzang.com>
Cc: Tim Chen <tim.c.chen@intel.com>
Cc: Ying Huang <ying.huang@intel.com>
Cc: Thieu Le <thieule@google.com>
Cc: Li Wang <dragonylffly@163.com>
Cc: Jarkko Sakkinen <jarkko.sakkinen@iki.fi>
The code cleanups fix up W=1 compiler warnings and some unnecessary checks. The
new Kconfig option, defaulting to N, allows the rarely used eCryptfs kernel to
userspace communication channel to be compiled out. This may be the first step
in it being eventually removed.
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Merge tag 'ecryptfs-3.9-rc2-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tyhicks/ecryptfs
Pull ecryptfs fixes from Tyler Hicks:
"Minor code cleanups and new Kconfig option to disable /dev/ecryptfs
The code cleanups fix up W=1 compiler warnings and some unnecessary
checks. The new Kconfig option, defaulting to N, allows the rarely
used eCryptfs kernel to userspace communication channel to be compiled
out. This may be the first step in it being eventually removed."
Hmm. I'm not sure whether these should be called "fixes", and it
probably should have gone in the merge window. But I'll let it slide.
* tag 'ecryptfs-3.9-rc2-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tyhicks/ecryptfs:
eCryptfs: allow userspace messaging to be disabled
eCryptfs: Fix redundant error check on ecryptfs_find_daemon_by_euid()
ecryptfs: ecryptfs_msg_ctx_alloc_to_free(): remove kfree() redundant null check
eCryptfs: decrypt_pki_encrypted_session_key(): remove kfree() redundant null check
eCryptfs: remove unneeded checks in virt_to_scatterlist()
eCryptfs: Fix -Wmissing-prototypes warnings
eCryptfs: Fix -Wunused-but-set-variable warnings
eCryptfs: initialize payload_len in keystore.c
When the userspace messaging (for the less common case of userspace key
wrap/unwrap via ecryptfsd) is not needed, allow eCryptfs to build with
it removed. This saves on kernel code size and reduces potential attack
surface by removing the /dev/ecryptfs node.
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
eCryptfs mount options do not
- Cleanups in the messaging code
- Better handling of empty files in the lower filesystem to improve usability.
Failed file creations are now cleaned up and empty lower files are converted
into eCryptfs during open().
- The write-through cache changes are being reverted due to bugs that are not
easy to fix. Stability outweighs the performance enhancements here.
- Improvement to the mount code to catch unsupported ciphers specified in the
mount options
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Merge tag 'ecryptfs-3.6-rc1-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tyhicks/ecryptfs
Pull ecryptfs fixes from Tyler Hicks:
- Fixes a bug when the lower filesystem mount options include 'acl',
but the eCryptfs mount options do not
- Cleanups in the messaging code
- Better handling of empty files in the lower filesystem to improve
usability. Failed file creations are now cleaned up and empty lower
files are converted into eCryptfs during open().
- The write-through cache changes are being reverted due to bugs that
are not easy to fix. Stability outweighs the performance
enhancements here.
- Improvement to the mount code to catch unsupported ciphers specified
in the mount options
* tag 'ecryptfs-3.6-rc1-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tyhicks/ecryptfs:
eCryptfs: check for eCryptfs cipher support at mount
eCryptfs: Revert to a writethrough cache model
eCryptfs: Initialize empty lower files when opening them
eCryptfs: Unlink lower inode when ecryptfs_create() fails
eCryptfs: Make all miscdev functions use daemon ptr in file private_data
eCryptfs: Remove unused messaging declarations and function
eCryptfs: Copy up POSIX ACL and read-only flags from lower mount
Historically, eCryptfs has only initialized lower files in the
ecryptfs_create() path. Lower file initialization is the act of writing
the cryptographic metadata from the inode's crypt_stat to the header of
the file. The ecryptfs_open() path already expects that metadata to be
in the header of the file.
A number of users have reported empty lower files in beneath their
eCryptfs mounts. Most of the causes for those empty files being left
around have been addressed, but the presence of empty files causes
problems due to the lack of proper cryptographic metadata.
To transparently solve this problem, this patch initializes empty lower
files in the ecryptfs_open() error path. If the metadata is unreadable
due to the lower inode size being 0, plaintext passthrough support is
not in use, and the metadata is stored in the header of the file (as
opposed to the user.ecryptfs extended attribute), the lower file will be
initialized.
The number of nested conditionals in ecryptfs_open() was getting out of
hand, so a helper function was created. To avoid the same nested
conditional problem, the conditional logic was reversed inside of the
helper function.
https://launchpad.net/bugs/911507
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Cc: John Johansen <john.johansen@canonical.com>
Cc: Colin Ian King <colin.king@canonical.com>
Now that a pointer to a valid struct ecryptfs_daemon is stored in the
private_data of an opened /dev/ecryptfs file, the remaining miscdev
functions can utilize the pointer rather than looking up the
ecryptfs_daemon at the beginning of each operation.
The security model of /dev/ecryptfs is simplified a little bit with this
patch. Upon opening /dev/ecryptfs, a per-user ecryptfs_daemon is
registered. Another daemon cannot be registered for that user until the
last file reference is released. During the lifetime of the
ecryptfs_daemon, access checks are not performed on the /dev/ecryptfs
operations because it is assumed that the application securely handles
the opened file descriptor and does not unintentionally leak it to
processes that are not trusted.
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Cc: Sasha Levin <levinsasha928@gmail.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>
ecryptfs_miscdev_read() and ecryptfs_miscdev_write() contained many
magic numbers for specifying packet header field sizes and offsets. This
patch defines those values and replaces the magic values.
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
The file creation path prematurely called d_instantiate() and
unlock_new_inode() before the eCryptfs inode info was fully
allocated and initialized and before the eCryptfs metadata was written
to the lower file.
This could result in race conditions in subsequent file and inode
operations leading to unexpected error conditions or a null pointer
dereference while attempting to use the unallocated memory.
https://launchpad.net/bugs/813146
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Cc: stable@kernel.org
The function ecryptfs_keyring_auth_tok_for_sig() has been modified in order
to search keys of both 'user' and 'encrypted' types.
Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Acked-by: Gianluca Ramunno <ramunno@polito.it>
Acked-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Some eCryptfs specific definitions, such as the current version and the
authentication token structure, are moved to the new include file
'include/linux/ecryptfs.h', in order to be available for all kernel
subsystems.
Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Acked-by: Gianluca Ramunno <ramunno@polito.it>
Acked-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Now that ecryptfs_lookup_interpose() is no longer using
ecryptfs_header_cache_2 to read in metadata, the kmem_cache can be
removed and the ecryptfs_header_cache_1 kmem_cache can be renamed to
ecryptfs_header_cache.
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
ecryptfs_lookup_interpose() has turned into spaghetti code over the
years. This is an effort to clean it up.
- Shorten overly descriptive variable names such as ecryptfs_dentry
- Simplify gotos and error paths
- Create helper function for reading plaintext i_size from metadata
It also includes an optimization when reading i_size from the metadata.
A complete page-sized kmem_cache_alloc() was being done to read in 16
bytes of metadata. The buffer for that is now statically declared.
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
Only unlock and d_add() new inodes after the plaintext inode size has
been read from the lower filesystem. This fixes a race condition that
was sometimes seen during a multi-job kernel build in an eCryptfs mount.
https://bugzilla.kernel.org/show_bug.cgi?id=36002
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
Reported-by: David <david@unsolicited.net>
Tested-by: David <david@unsolicited.net>
The eCryptfs inode get, initialization, and dentry interposition code
has two separate paths. One is for when dentry interposition is needed
after doing things like a mkdir in the lower filesystem and the other
is needed after a lookup. Unlocking new inodes and doing a d_add() needs
to happen at different times, depending on which type of dentry
interposing is being done.
This patch cleans up the inode get and initialization code paths and
splits them up so that the locking and d_add() differences mentioned
above can be handled appropriately in a later patch.
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
Tested-by: David <david@unsolicited.net>
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>
When failing to read the lower file's crypto metadata during a lookup,
eCryptfs must continue on without throwing an error. For example, there
may be a plaintext file in the lower mount point that the user wants to
delete through the eCryptfs mount.
If an error is encountered while reading the metadata in lookup(), the
eCryptfs inode's size could be incorrect. We must be sure to reread the
plaintext inode size from the metadata when performing an open() or
setattr(). The metadata is already being read in those paths, so this
adds minimal performance overhead.
This patch introduces a flag which will track whether or not the
plaintext inode size has been read so that an incorrect i_size can be
fixed in the open() or setattr() paths.
https://bugs.launchpad.net/bugs/509180
Cc: <stable@kernel.org>
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
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>
Authentication tokens content may change if another requestor calls the
update() method of the corresponding key. The new function
ecryptfs_verify_auth_tok_from_key() retrieves the authentication token from
the provided key and verifies if it is still valid before being used to
encrypt or decrypt an eCryptfs file.
Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
[tyhicks: Minor formatting changes]
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
The size of the 'keysig' array is incremented of one byte in order to make
room for the NULL character. The 'keysig' variable is used, in the function
ecryptfs_generate_key_packet_set(), to find an authentication token with
the given signature and is printed a debug message if it cannot be
retrieved.
Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
This patch removes the 'num_global_auth_toks' field of the
ecryptfs_mount_crypt_stat structure, used to count the number of items in
the 'global_auth_tok_list' list. This variable is not needed because there
are no checks based upon it.
Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
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>
Now that grow_file() is not called in the ecryptfs_create() path, the
ECRYPTFS_NEW_FILE flag is no longer needed. It helped
ecryptfs_readpage() know not to decrypt zeroes that were read from the
lower file in the grow_file() path.
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
Add __attribute__((format... to __ecryptfs_printk
Make formats and arguments match.
Add casts to (unsigned long long) for %llu.
Signed-off-by: Joe Perches <joe@perches.com>
[tyhicks: 80 columns cleanup and fixed typo]
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
The definition of ECRYPTFS_SUPER_MAGIC has been moved to the include
file 'linux/magic.h' to become available to other kernel subsystems.
Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ecryptfs/ecryptfs-2.6:
eCryptfs: Print mount_auth_tok_only param in ecryptfs_show_options
ecryptfs: added ecryptfs_mount_auth_tok_only mount parameter
ecryptfs: checking return code of ecryptfs_find_auth_tok_for_sig()
ecryptfs: release keys loaded in ecryptfs_keyring_auth_tok_for_sig()
eCryptfs: Clear LOOKUP_OPEN flag when creating lower file
ecryptfs: call vfs_setxattr() in ecryptfs_setxattr()
This patch adds a new mount parameter 'ecryptfs_mount_auth_tok_only' to
force ecryptfs to use only authentication tokens which signature has
been specified at mount time with parameters 'ecryptfs_sig' and
'ecryptfs_fnek_sig'. In this way, after disabling the passthrough and
the encrypted view modes, it's possible to make available to users only
files encrypted with the specified authentication token.
Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Cc: Dustin Kirkland <kirkland@canonical.com>
Cc: James Morris <jmorris@namei.org>
[Tyler: Clean up coding style errors found by checkpatch]
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
David Howells