Commit Graph

214 Commits

Author SHA1 Message Date
Christoph Hellwig 6cfd014842 push BKL down into ->put_super
Move BKL into ->put_super from the only caller.  A couple of
filesystems had trivial enough ->put_super (only kfree and NULLing of
s_fs_info + stuff in there) to not get any locking: coda, cramfs, efs,
hugetlbfs, omfs, qnx4, shmem, all others got the full treatment.  Most
of them probably don't need it, but I'd rather sort that out individually.
Preferably after all the other BKL pushdowns in that area.

[AV: original used to move lock_super() down as well; these changes are
removed since we don't do lock_super() at all in generic_shutdown_super()
now]
[AV: fuse, btrfs and xfs are known to need no damn BKL, exempt]

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-11 21:36:07 -04:00
Al Viro 6f5bbff9a1 Convert obvious places to deactivate_locked_super()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-05-09 10:49:40 -04:00
Tyler Hicks ac20100df7 eCryptfs: Fix min function comparison warning
This warning shows up on 64 bit builds:

fs/ecryptfs/inode.c:693: warning: comparison of distinct pointer types
lacks a cast

Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
2009-04-27 13:31:12 -05:00
Randy Dunlap 802b352f29 ecryptfs: fix printk format warning
fs/ecryptfs/inode.c:670: warning: format '%d' expects type 'int', but argument 3 has type 'size_t'

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
Cc: Dustin Kirkland <kirkland@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2009-04-27 13:10:06 -05:00
Tyler Hicks 3a6b42cadc eCryptfs: Larger buffer for encrypted symlink targets
When using filename encryption with eCryptfs, the value of the symlink
in the lower filesystem is encrypted and stored as a Tag 70 packet.
This results in a longer symlink target than if the target value wasn't
encrypted.

Users were reporting these messages in their syslog:

[ 45.653441] ecryptfs_parse_tag_70_packet: max_packet_size is [56]; real
packet size is [51]
[ 45.653444] ecryptfs_decode_and_decrypt_filename: Could not parse tag
70 packet from filename; copying through filename as-is

This was due to bufsiz, one the arguments in readlink(), being used to
when allocating the buffer passed to the lower inode's readlink().
That symlink target may be very large, but when decoded and decrypted,
could end up being smaller than bufsize.

To fix this, the buffer passed to the lower inode's readlink() will
always be PATH_MAX in size when filename encryption is enabled.  Any
necessary truncation occurs after the decoding and decrypting.

Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
2009-04-22 17:02:46 -05:00
Tyler Hicks ca8e34f2b0 eCryptfs: Lock lower directory inode mutex during lookup
This patch locks the lower directory inode's i_mutex before calling
lookup_one_len() to find the appropriate dentry in the lower filesystem.
This bug was found thanks to the warning set in commit 2f9092e1.

Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
2009-04-22 16:27:12 -05:00
Tyler Hicks e77cc8d243 eCryptfs: Remove ecryptfs_unlink_sigs warnings
A feature was added to the eCryptfs umount helper to automatically
unlink the keys used for an eCryptfs mount from the kernel keyring upon
umount.  This patch keeps the unrecognized mount option warnings for
ecryptfs_unlink_sigs out of the logs.

Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
2009-04-22 04:08:46 -05:00
Tyler Hicks 13a791b4e6 eCryptfs: Fix data corruption when using ecryptfs_passthrough
ecryptfs_passthrough is a mount option that allows eCryptfs to allow
data to be written to non-eCryptfs files in the lower filesystem.  The
passthrough option was causing data corruption due to it not always
being treated as a non-eCryptfs file.

The first 8 bytes of an eCryptfs file contains the decrypted file size.
This value was being written to the non-eCryptfs files, too.  Also,
extra 0x00 characters were being written to make the file size a
multiple of PAGE_CACHE_SIZE.

Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
2009-04-22 03:54:13 -05:00
Tyler Hicks 3a5203ab3c eCryptfs: Print FNEK sig properly in /proc/mounts
The filename encryption key signature is not properly displayed in
/proc/mounts.  The "ecryptfs_sig=" mount option name is displayed for
all global authentication tokens, included those for filename keys.

This patch checks the global authentication token flags to determine if
the key is a FEKEK or FNEK and prints the appropriate mount option name
before the signature.

Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
2009-04-22 03:54:13 -05:00
Tyler Hicks 57ea34d199 eCryptfs: NULL pointer dereference in ecryptfs_send_miscdev()
If data is NULL, msg_ctx->msg is set to NULL and then dereferenced
afterwards.  ecryptfs_send_raw_message() is the only place that
ecryptfs_send_miscdev() is called with data being NULL, but the only
caller of that function (ecryptfs_process_helo()) is never called.  In
short, there is currently no way to trigger the NULL pointer
dereference.

This patch removes the two unused functions and modifies
ecryptfs_send_miscdev() to remove the NULL dereferences.

Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
2009-04-22 03:54:13 -05:00
Tyler Hicks ae6e84596e eCryptfs: Copy lower inode attrs before dentry instantiation
Copies the lower inode attributes to the upper inode before passing the
upper inode to d_instantiate().  This is important for
security_d_instantiate().

The problem was discovered by a user seeing SELinux denials like so:

type=AVC msg=audit(1236812817.898:47): avc:  denied  { 0x100000 } for
pid=3584 comm="httpd" name="testdir" dev=ecryptfs ino=943872
scontext=root:system_r:httpd_t:s0
tcontext=root:object_r:httpd_sys_content_t:s0 tclass=file

Notice target class is file while testdir is really a directory,
confusing the permission translation (0x100000) due to the wrong i_mode.

Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
2009-04-22 03:54:12 -05:00
Li Zefan fd56d242b3 ecryptfs: use memdup_user()
Remove open-coded memdup_user().

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-04-20 23:02:51 -04:00
Johannes Weiner 00fcf2cb6f ecryptfs: use kzfree()
Use kzfree() instead of memset() + kfree().

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Pekka Enberg <penberg@cs.helsinki.fi>
Acked-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-01 08:59:23 -07:00
Al Viro 5a3fd05a9b constify dentry_operations: ecryptfs
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-03-27 14:44:01 -04:00
Tyler Hicks 2aac0cf886 eCryptfs: NULL crypt_stat dereference during lookup
If ecryptfs_encrypted_view or ecryptfs_xattr_metadata were being
specified as mount options, a NULL pointer dereference of crypt_stat
was possible during lookup.

This patch moves the crypt_stat assignment into
ecryptfs_lookup_and_interpose_lower(), ensuring that crypt_stat
will not be NULL before we attempt to dereference it.

Thanks to Dan Carpenter and his static analysis tool, smatch, for
finding this bug.

Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
Acked-by: Dustin Kirkland <kirkland@canonical.com>
Cc: Dan Carpenter <error27@gmail.com>
Cc: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-22 11:20:43 -07:00
Tyler Hicks 8faece5f90 eCryptfs: Allocate a variable number of pages for file headers
When allocating the memory used to store the eCryptfs header contents, a
single, zeroed page was being allocated with get_zeroed_page().
However, the size of an eCryptfs header is either PAGE_CACHE_SIZE or
ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE (8192), whichever is larger, and is
stored in the file's private_data->crypt_stat->num_header_bytes_at_front
field.

ecryptfs_write_metadata_to_contents() was using
num_header_bytes_at_front to decide how many bytes should be written to
the lower filesystem for the file header.  Unfortunately, at least 8K
was being written from the page, despite the chance of the single,
zeroed page being smaller than 8K.  This resulted in random areas of
kernel memory being written between the 0x1000 and 0x1FFF bytes offsets
in the eCryptfs file headers if PAGE_SIZE was 4K.

This patch allocates a variable number of pages, calculated with
num_header_bytes_at_front, and passes the number of allocated pages
along to ecryptfs_write_metadata_to_contents().

Thanks to Florian Streibelt for reporting the data leak and working with
me to find the problem.  2.6.28 is the only kernel release with this
vulnerability.  Corresponds to CVE-2009-0787

Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
Acked-by: Dustin Kirkland <kirkland@canonical.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Eugene Teo <eugeneteo@kernel.sg>
Cc: Greg KH <greg@kroah.com>
Cc: dann frazier <dannf@dannf.org>
Cc: Serge E. Hallyn <serue@us.ibm.com>
Cc: Florian Streibelt <florian@f-streibelt.de>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-22 11:20:43 -07:00
Tyler Hicks 84814d642a eCryptfs: don't encrypt file key with filename key
eCryptfs has file encryption keys (FEK), file encryption key encryption
keys (FEKEK), and filename encryption keys (FNEK).  The per-file FEK is
encrypted with one or more FEKEKs and stored in the header of the
encrypted file.  I noticed that the FEK is also being encrypted by the
FNEK.  This is a problem if a user wants to use a different FNEK than
their FEKEK, as their file contents will still be accessible with the
FNEK.

This is a minimalistic patch which prevents the FNEKs signatures from
being copied to the inode signatures list.  Ultimately, it keeps the FEK
from being encrypted with a FNEK.

Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
Cc: Serge Hallyn <serue@us.ibm.com>
Acked-by: Dustin Kirkland <kirkland@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-14 11:57:22 -07:00
Tyler Hicks fd9fc842bb eCryptfs: Regression in unencrypted filename symlinks
The addition of filename encryption caused a regression in unencrypted
filename symlink support.  ecryptfs_copy_filename() is used when dealing
with unencrypted filenames and it reported that the new, copied filename
was a character longer than it should have been.

This caused the return value of readlink() to count the NULL byte of the
symlink target.  Most applications don't care about the extra NULL byte,
but a version control system (bzr) helped in discovering the bug.

Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-02-06 18:36:40 -08:00
Alexey Dobriyan 295c896cb9 fs/Kconfig: move ecryptfs out
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
2009-01-22 13:15:56 +03:00
Qinghuang Feng f70f582f00 fs/ecryptfs/inode.c: cleanup kerneldoc
Arguments lower_dentry and ecryptfs_dentry in ecryptfs_create_underlying_file()
have been merged into dentry, now fix it.

Signed-off-by: Qinghuang Feng <qhfeng.kernel@gmail.com>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Michael Halcrow <mhalcrow@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-06 15:59:22 -08:00
Michael Halcrow 71c11c378f eCryptfs: Clean up ecryptfs_decode_from_filename()
Flesh out the comments for ecryptfs_decode_from_filename(). Remove the
return condition, since it is always 0.

Signed-off-by: Michael Halcrow <mhalcrow@us.ibm.com>
Cc: Dustin Kirkland <dustin.kirkland@gmail.com>
Cc: Eric Sandeen <sandeen@redhat.com>
Cc: Tyler Hicks <tchicks@us.ibm.com>
Cc: David Kleikamp <shaggy@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-06 15:59:22 -08:00
Michael Halcrow 7d8bc2be51 eCryptfs: kerneldoc for ecryptfs_parse_tag_70_packet()
Kerneldoc updates for ecryptfs_parse_tag_70_packet().

Signed-off-by: Michael Halcrow <mhalcrow@us.ibm.com>
Cc: Dustin Kirkland <dustin.kirkland@gmail.com>
Cc: Eric Sandeen <sandeen@redhat.com>
Cc: Tyler Hicks <tchicks@us.ibm.com>
Cc: David Kleikamp <shaggy@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-06 15:59:22 -08:00
Michael Halcrow a8f12864c5 eCryptfs: Fix data types (int/size_t)
Correct several format string data type specifiers.  Correct filename size
data types; they should be size_t rather than int when passed as
parameters to some other functions (although note that the filenames will
never be larger than int).

Signed-off-by: Michael Halcrow <mhalcrow@us.ibm.com>
Cc: Dustin Kirkland <dustin.kirkland@gmail.com>
Cc: Eric Sandeen <sandeen@redhat.com>
Cc: Tyler Hicks <tchicks@us.ibm.com>
Cc: David Kleikamp <shaggy@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-06 15:59:22 -08:00
Michael Halcrow df261c52ab eCryptfs: Replace %Z with %z
%Z is a gcc-ism. Using %z instead.

Signed-off-by: Michael Halcrow <mhalcrow@us.ibm.com>
Cc: Dustin Kirkland <dustin.kirkland@gmail.com>
Cc: Eric Sandeen <sandeen@redhat.com>
Cc: Tyler Hicks <tchicks@us.ibm.com>
Cc: David Kleikamp <shaggy@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-06 15:59:22 -08:00
Michael Halcrow 87c94c4df0 eCryptfs: Filename Encryption: mount option
Enable mount-wide filename encryption by providing the Filename Encryption
Key (FNEK) signature as a mount option.  Note that the ecryptfs-utils
userspace package versions 61 or later support this option.

When mounting with ecryptfs-utils version 61 or later, the mount helper
will detect the availability of the passphrase-based filename encryption
in the kernel (via the eCryptfs sysfs handle) and query the user
interactively as to whether or not he wants to enable the feature for the
mount.  If the user enables filename encryption, the mount helper will
then prompt for the FNEK signature that the user wishes to use, suggesting
by default the signature for the mount passphrase that the user has
already entered for encrypting the file contents.

When not using the mount helper, the user can specify the signature for
the passphrase key with the ecryptfs_fnek_sig= mount option.  This key
must be available in the user's keyring.  The mount helper usually takes
care of this step.  If, however, the user is not mounting with the mount
helper, then he will need to enter the passphrase key into his keyring
with some other utility prior to mounting, such as ecryptfs-manager.

Signed-off-by: Michael Halcrow <mhalcrow@us.ibm.com>
Cc: Dustin Kirkland <dustin.kirkland@gmail.com>
Cc: Eric Sandeen <sandeen@redhat.com>
Cc: Tyler Hicks <tchicks@us.ibm.com>
Cc: David Kleikamp <shaggy@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-06 15:59:22 -08:00
Michael Halcrow addd65ad8d eCryptfs: Filename Encryption: filldir, lookup, and readlink
Make the requisite modifications to ecryptfs_filldir(), ecryptfs_lookup(),
and ecryptfs_readlink() to call out to filename encryption functions.
Propagate filename encryption policy flags from mount-wide crypt_stat to
inode crypt_stat.

Signed-off-by: Michael Halcrow <mhalcrow@us.ibm.com>
Cc: Dustin Kirkland <dustin.kirkland@gmail.com>
Cc: Eric Sandeen <sandeen@redhat.com>
Cc: Tyler Hicks <tchicks@us.ibm.com>
Cc: David Kleikamp <shaggy@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-06 15:59:22 -08:00
Michael Halcrow 51ca58dcc9 eCryptfs: Filename Encryption: Encoding and encryption functions
These functions support encrypting and encoding the filename contents.
The encrypted filename contents may consist of any ASCII characters.  This
patch includes a custom encoding mechanism to map the ASCII characters to
a reduced character set that is appropriate for filenames.

Signed-off-by: Michael Halcrow <mhalcrow@us.ibm.com>
Cc: Dustin Kirkland <dustin.kirkland@gmail.com>
Cc: Eric Sandeen <sandeen@redhat.com>
Cc: Tyler Hicks <tchicks@us.ibm.com>
Cc: David Kleikamp <shaggy@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-06 15:59:21 -08:00
Michael Halcrow a34f60f748 eCryptfs: Filename Encryption: Header updates
Extensions to the header file to support filename encryption.

Signed-off-by: Michael Halcrow <mhalcrow@us.ibm.com>
Cc: Dustin Kirkland <dustin.kirkland@gmail.com>
Cc: Eric Sandeen <sandeen@redhat.com>
Cc: Tyler Hicks <tchicks@us.ibm.com>
Cc: David Kleikamp <shaggy@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-06 15:59:21 -08:00
Michael Halcrow 9c79f34f7e eCryptfs: Filename Encryption: Tag 70 packets
This patchset implements filename encryption via a passphrase-derived
mount-wide Filename Encryption Key (FNEK) specified as a mount parameter.
Each encrypted filename has a fixed prefix indicating that eCryptfs should
try to decrypt the filename.  When eCryptfs encounters this prefix, it
decodes the filename into a tag 70 packet and then decrypts the packet
contents using the FNEK, setting the filename to the decrypted filename.
Both unencrypted and encrypted filenames can reside in the same lower
filesystem.

Because filename encryption expands the length of the filename during the
encoding stage, eCryptfs will not properly handle filenames that are
already near the maximum filename length.

In the present implementation, eCryptfs must be able to produce a match
against the lower encrypted and encoded filename representation when given
a plaintext filename.  Therefore, two files having the same plaintext name
will encrypt and encode into the same lower filename if they are both
encrypted using the same FNEK.  This can be changed by finding a way to
replace the prepended bytes in the blocked-aligned filename with random
characters; they are hashes of the FNEK right now, so that it is possible
to deterministically map from a plaintext filename to an encrypted and
encoded filename in the lower filesystem.  An implementation using random
characters will have to decode and decrypt every single directory entry in
any given directory any time an event occurs wherein the VFS needs to
determine whether a particular file exists in the lower directory and the
decrypted and decoded filenames have not yet been extracted for that
directory.

Thanks to Tyler Hicks and David Kleikamp for assistance in the development
of this patchset.

This patch:

A tag 70 packet contains a filename encrypted with a Filename Encryption
Key (FNEK).  This patch implements functions for writing and parsing tag
70 packets.  This patch also adds definitions and extends structures to
support filename encryption.

Signed-off-by: Michael Halcrow <mhalcrow@us.ibm.com>
Cc: Dustin Kirkland <dustin.kirkland@gmail.com>
Cc: Eric Sandeen <sandeen@redhat.com>
Cc: Tyler Hicks <tchicks@us.ibm.com>
Cc: David Kleikamp <shaggy@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-06 15:59:21 -08:00
Linus Torvalds 520c853466 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6:
  inotify: fix type errors in interfaces
  fix breakage in reiserfs_new_inode()
  fix the treatment of jfs special inodes
  vfs: remove duplicate code in get_fs_type()
  add a vfs_fsync helper
  sys_execve and sys_uselib do not call into fsnotify
  zero i_uid/i_gid on inode allocation
  inode->i_op is never NULL
  ntfs: don't NULL i_op
  isofs check for NULL ->i_op in root directory is dead code
  affs: do not zero ->i_op
  kill suid bit only for regular files
  vfs: lseek(fd, 0, SEEK_CUR) race condition
2009-01-05 18:32:06 -08:00
Christoph Hellwig 4c728ef583 add a vfs_fsync helper
Fsync currently has a fdatawrite/fdatawait pair around the method call,
and a mutex_lock/unlock of the inode mutex.  All callers of fsync have
to duplicate this, but we have a few and most of them don't quite get
it right.  This patch adds a new vfs_fsync that takes care of this.
It's a little more complicated as usual as ->fsync might get a NULL file
pointer and just a dentry from nfsd, but otherwise gets afile and we
want to take the mapping and file operations from it when it is there.

Notes on the fsync callers:

 - ecryptfs wasn't calling filemap_fdatawrite / filemap_fdatawait on the
   	lower file
 - coda wasn't calling filemap_fdatawrite / filemap_fdatawait on the host
	file, and returning 0 when ->fsync was missing
 - shm wasn't calling either filemap_fdatawrite / filemap_fdatawait nor
   taking i_mutex.  Now given that shared memory doesn't have disk
   backing not doing anything in fsync seems fine and I left it out of
   the vfs_fsync conversion for now, but in that case we might just
   not pass it through to the lower file at all but just call the no-op
   simple_sync_file directly.

[and now actually export vfs_fsync]

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-01-05 11:54:28 -05:00
Al Viro acfa4380ef inode->i_op is never NULL
We used to have rather schizophrenic set of checks for NULL ->i_op even
though it had been eliminated years ago.  You'd need to go out of your
way to set it to NULL explicitly _and_ a bunch of code would die on
such inodes anyway.  After killing two remaining places that still
did that bogosity, all that crap can go away.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-01-05 11:54:28 -05:00
Nick Piggin 54566b2c15 fs: symlink write_begin allocation context fix
With the write_begin/write_end aops, page_symlink was broken because it
could no longer pass a GFP_NOFS type mask into the point where the
allocations happened.  They are done in write_begin, which would always
assume that the filesystem can be entered from reclaim.  This bug could
cause filesystem deadlocks.

The funny thing with having a gfp_t mask there is that it doesn't really
allow the caller to arbitrarily tinker with the context in which it can be
called.  It couldn't ever be GFP_ATOMIC, for example, because it needs to
take the page lock.  The only thing any callers care about is __GFP_FS
anyway, so turn that into a single flag.

Add a new flag for write_begin, AOP_FLAG_NOFS.  Filesystems can now act on
this flag in their write_begin function.  Change __grab_cache_page to
accept a nofs argument as well, to honour that flag (while we're there,
change the name to grab_cache_page_write_begin which is more instructive
and does away with random leading underscores).

This is really a more flexible way to go in the end anyway -- if a
filesystem happens to want any extra allocations aside from the pagecache
ones in ints write_begin function, it may now use GFP_KERNEL (rather than
GFP_NOFS) for common case allocations (eg.  ocfs2_alloc_write_ctxt, for a
random example).

[kosaki.motohiro@jp.fujitsu.com: fix ubifs]
[kosaki.motohiro@jp.fujitsu.com: fix fuse]
Signed-off-by: Nick Piggin <npiggin@suse.de>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: <stable@kernel.org>		[2.6.28.x]
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
[ Cleaned up the calling convention: just pass in the AOP flags
  untouched to the grab_cache_page_write_begin() function.  That
  just simplifies everybody, and may even allow future expansion of the
  logic.   - Linus ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-04 13:33:20 -08:00
Duane Griffin a17d5232de eCryptfs: check readlink result was not an error before using it
The result from readlink is being used to index into the link name
buffer without checking whether it is a valid length. If readlink
returns an error this will fault or cause memory corruption.

Cc: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
Cc: Dustin Kirkland <kirkland@canonical.com>
Cc: ecryptfs-devel@lists.launchpad.net
Signed-off-by: Duane Griffin <duaneg@dghda.com>
Acked-by: Michael Halcrow <mhalcrow@us.ibm.com>
Acked-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-12-31 18:07:38 -05:00
James Morris ec98ce480a Merge branch 'master' into next
Conflicts:
	fs/nfsd/nfs4recover.c

Manually fixed above to use new creds API functions, e.g.
nfs4_save_creds().

Signed-off-by: James Morris <jmorris@namei.org>
2008-12-04 17:16:36 +11:00
Serge Hallyn 18b6e0414e User namespaces: set of cleanups (v2)
The user_ns is moved from nsproxy to user_struct, so that a struct
cred by itself is sufficient to determine access (which it otherwise
would not be).  Corresponding ecryptfs fixes (by David Howells) are
here as well.

Fix refcounting.  The following rules now apply:
        1. The task pins the user struct.
        2. The user struct pins its user namespace.
        3. The user namespace pins the struct user which created it.

User namespaces are cloned during copy_creds().  Unsharing a new user_ns
is no longer possible.  (We could re-add that, but it'll cause code
duplication and doesn't seem useful if PAM doesn't need to clone user
namespaces).

When a user namespace is created, its first user (uid 0) gets empty
keyrings and a clean group_info.

This incorporates a previous patch by David Howells.  Here
is his original patch description:

>I suggest adding the attached incremental patch.  It makes the following
>changes:
>
> (1) Provides a current_user_ns() macro to wrap accesses to current's user
>     namespace.
>
> (2) Fixes eCryptFS.
>
> (3) Renames create_new_userns() to create_user_ns() to be more consistent
>     with the other associated functions and because the 'new' in the name is
>     superfluous.
>
> (4) Moves the argument and permission checks made for CLONE_NEWUSER to the
>     beginning of do_fork() so that they're done prior to making any attempts
>     at allocation.
>
> (5) Calls create_user_ns() after prepare_creds(), and gives it the new creds
>     to fill in rather than have it return the new root user.  I don't imagine
>     the new root user being used for anything other than filling in a cred
>     struct.
>
>     This also permits me to get rid of a get_uid() and a free_uid(), as the
>     reference the creds were holding on the old user_struct can just be
>     transferred to the new namespace's creator pointer.
>
> (6) Makes create_user_ns() reset the UIDs and GIDs of the creds under
>     preparation rather than doing it in copy_creds().
>
>David

>Signed-off-by: David Howells <dhowells@redhat.com>

Changelog:
	Oct 20: integrate dhowells comments
		1. leave thread_keyring alone
		2. use current_user_ns() in set_user()

Signed-off-by: Serge Hallyn <serue@us.ibm.com>
2008-11-24 18:57:41 -05:00
Michael Halcrow ac97b9f9a2 eCryptfs: Allocate up to two scatterlists for crypto ops on keys
I have received some reports of out-of-memory errors on some older AMD
architectures.  These errors are what I would expect to see if
crypt_stat->key were split between two separate pages.  eCryptfs should
not assume that any of the memory sent through virt_to_scatterlist() is
all contained in a single page, and so this patch allocates two
scatterlist structs instead of one when processing keys.  I have received
confirmation from one person affected by this bug that this patch resolves
the issue for him, and so I am submitting it for inclusion in a future
stable release.

Note that virt_to_scatterlist() runs sg_init_table() on the scatterlist
structs passed to it, so the calls to sg_init_table() in
decrypt_passphrase_encrypted_session_key() are redundant.

Signed-off-by: Michael Halcrow <mhalcrow@us.ibm.com>
Reported-by: Paulo J. S. Silva <pjssilva@ime.usp.br>
Cc: "Leon Woestenberg" <leon.woestenberg@gmail.com>
Cc: Tim Gardner <tim.gardner@canonical.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-11-19 18:49:58 -08:00
David Howells 745ca2475a CRED: Pass credentials through dentry_open()
Pass credentials through dentry_open() so that the COW creds patch can have
SELinux's flush_unauthorized_files() pass the appropriate creds back to itself
when it opens its null chardev.

The security_dentry_open() call also now takes a creds pointer, as does the
dentry_open hook in struct security_operations.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: James Morris <jmorris@namei.org>
Signed-off-by: James Morris <jmorris@namei.org>
2008-11-14 10:39:22 +11:00
David Howells 4eea03539d CRED: Wrap task credential accesses in the eCryptFS filesystem
Wrap access to task credentials so that they can be separated more easily from
the task_struct during the introduction of COW creds.

Change most current->(|e|s|fs)[ug]id to current_(|e|s|fs)[ug]id().

Change some task->e?[ug]id to task_e?[ug]id().  In some places it makes more
sense to use RCU directly rather than a convenient wrapper; these will be
addressed by later patches.

Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: James Morris <jmorris@namei.org>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Cc: Mike Halcrow <mhalcrow@us.ibm.com>
Cc: Phillip Hellewell <phillip@hellewell.homeip.net>
Cc: ecryptfs-devel@lists.sourceforge.net
Signed-off-by: James Morris <jmorris@namei.org>
2008-11-14 10:38:49 +11:00
Eric Sandeen 87b811c3f9 ecryptfs: fix memory corruption when storing crypto info in xattrs
When ecryptfs allocates space to write crypto headers into, before copying
it out to file headers or to xattrs, it looks at the value of
crypt_stat->num_header_bytes_at_front to determine how much space it
needs.  This is also used as the file offset to the actual encrypted data,
so for xattr-stored crypto info, the value was zero.

So, we kzalloc'd 0 bytes, and then ran off to write to that memory.
(Which returned as ZERO_SIZE_PTR, so we explode quickly).

The right answer is to always allocate a page to write into; the current
code won't ever write more than that (this is enforced by the
(PAGE_CACHE_SIZE - offset) length in the call to
ecryptfs_generate_key_packet_set).  To be explicit about this, we now send
in a "max" parameter, rather than magically using PAGE_CACHE_SIZE there.

Also, since the pointer we pass down the callchain eventually gets the
virt_to_page() treatment, we should be using a alloc_page variant, not
kzalloc (see also 7fcba05437)

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Acked-by: Michael Halcrow <mhalcrow@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-30 11:38:46 -07:00
Al Viro 421748ecde [PATCH] assorted path_lookup() -> kern_path() conversions
more nameidata eviction

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-10-23 05:12:52 -04:00
Tyler Hicks 624ae52845 eCryptfs: remove netlink transport
The netlink transport code has not worked for a while and the miscdev
transport is a simpler solution.  This patch removes the netlink code and
makes the miscdev transport the only eCryptfs kernel to userspace
transport.

Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
Cc: Michael Halcrow <mhalcrow@us.ibm.com>
Cc: Dustin Kirkland <kirkland@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-16 11:21:39 -07:00
Badari Pulavarty 807b7ebe41 ecryptfs: convert to use new aops
Convert ecryptfs to use write_begin/write_end

Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com>
Acked-by: Michael Halcrow <mhalcrow@us.ibm.com>
Cc: Dave Kleikamp <shaggy@austin.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-16 11:21:39 -07:00
Michael Halcrow 7d6c704558 eCryptfs: remove retry loop in ecryptfs_readdir()
The retry block in ecryptfs_readdir() has been in the eCryptfs code base
for a while, apparently for no good reason.  This loop could potentially
run without terminating.  This patch removes the loop, instead erroring
out if vfs_readdir() on the lower file fails.

Signed-off-by: Michael Halcrow <mhalcrow@us.ibm.com>
Reported-by: Al Viro <viro@ZinIV.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-16 11:21:38 -07:00
Steven Whitehouse a447c09324 vfs: Use const for kernel parser table
This is a much better version of a previous patch to make the parser
tables constant. Rather than changing the typedef, we put the "const" in
all the various places where its required, allowing the __initconst
exception for nfsroot which was the cause of the previous trouble.

This was posted for review some time ago and I believe its been in -mm
since then.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Cc: Alexander Viro <aviro@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-13 10:10:37 -07:00
Eric Sandeen 7fcba05437 eCryptfs: use page_alloc not kmalloc to get a page of memory
With SLUB debugging turned on in 2.6.26, I was getting memory corruption
when testing eCryptfs.  The root cause turned out to be that eCryptfs was
doing kmalloc(PAGE_CACHE_SIZE); virt_to_page() and treating that as a nice
page-aligned chunk of memory.  But at least with SLUB debugging on, this
is not always true, and the page we get from virt_to_page does not
necessarily match the PAGE_CACHE_SIZE worth of memory we got from kmalloc.

My simple testcase was 2 loops doing "rm -f fileX; cp /tmp/fileX ." for 2
different multi-megabyte files.  With this change I no longer see the
corruption.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Acked-by: Michael Halcrow <mhalcrow@us.ibm.com>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: <stable@kernel.org>		[2.6.25.x, 2.6.26.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-28 16:30:21 -07:00
Al Viro f419a2e3b6 [PATCH] kill nameidata passing to permission(), rename to inode_permission()
Incidentally, the name that gives hundreds of false positives on grep
is not a good idea...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-07-26 20:53:31 -04:00
Miklos Szeredi db2e747b14 [patch 5/5] vfs: remove mode parameter from vfs_symlink()
Remove the unused mode parameter from vfs_symlink and callers.

Thanks to Tetsuo Handa for noticing.

CC: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2008-07-26 20:53:18 -04:00
Al Viro e6305c43ed [PATCH] sanitize ->permission() prototype
* kill nameidata * argument; map the 3 bits in ->flags anybody cares
  about to new MAY_... ones and pass with the mask.
* kill redundant gfs2_iop_permission()
* sanitize ecryptfs_permission()
* fix remaining places where ->permission() instances might barf on new
  MAY_... found in mask.

The obvious next target in that direction is permission(9)

folded fix for nfs_permission() breakage from Miklos Szeredi <mszeredi@suse.cz>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-07-26 20:53:14 -04:00
Alexey Dobriyan 51cc50685a SL*B: drop kmem cache argument from constructor
Kmem cache passed to constructor is only needed for constructors that are
themselves multiplexeres.  Nobody uses this "feature", nor does anybody uses
passed kmem cache in non-trivial way, so pass only pointer to object.

Non-trivial places are:
	arch/powerpc/mm/init_64.c
	arch/powerpc/mm/hugetlbpage.c

This is flag day, yes.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Acked-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Jon Tollefson <kniht@linux.vnet.ibm.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Matt Mackall <mpm@selenic.com>
[akpm@linux-foundation.org: fix arch/powerpc/mm/hugetlbpage.c]
[akpm@linux-foundation.org: fix mm/slab.c]
[akpm@linux-foundation.org: fix ubifs]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-26 12:00:07 -07:00