linux-stable.git/fs/ecryptfs, branch linux-2.6.34.y

eCryptfs: Properly check for O_RDONLY flag before doing privileged open

2014-02-10T21:11:37+00:00

commit 9fe79d7600497ed8a95c3981cbe5b73ab98222f0 upstream.

If the first attempt at opening the lower file read/write fails,
eCryptfs will retry using a privileged kthread. However, the privileged
retry should not happen if the lower file's inode is read-only because a
read/write open will still be unsuccessful.

The check for determining if the open should be retried was intended to
be based on the access mode of the lower file's open flags being
O_RDONLY, but the check was incorrectly performed. This would cause the
open to be retried by the privileged kthread, resulting in a second
failed open of the lower file. This patch corrects the check to
determine if the open request should be handled by the privileged
kthread.

Signed-off-by: Tyler Hicks 
Reported-by: Dan Carpenter 
Acked-by: Dan Carpenter 
Signed-off-by: Paul Gortmaker

eCryptfs: Copy up lower inode attrs after setting lower xattr

2014-02-10T21:11:27+00:00

commit 545d680938be1e86a6c5250701ce9abaf360c495 upstream.

After passing through a ->setxattr() call, eCryptfs needs to copy the
inode attributes from the lower inode to the eCryptfs inode, as they
may have changed in the lower filesystem's ->setxattr() path.

One example is if an extended attribute containing a POSIX Access
Control List is being set. The new ACL may cause the lower filesystem to
modify the mode of the lower inode and the eCryptfs inode would need to
be updated to reflect the new mode.

https://launchpad.net/bugs/926292

Signed-off-by: Tyler Hicks 
Reported-by: Sebastien Bacher 
Cc: John Johansen 
Signed-off-by: Paul Gortmaker

ecryptfs: call vfs_setxattr() in ecryptfs_setxattr()

2014-02-10T21:11:27+00:00

commit 48b512e6857139393cdfce26348c362b87537018 upstream.

Ecryptfs is a stackable filesystem which relies on lower filesystems the
ability of setting/getting extended attributes.

If there is a security module enabled on the system it updates the
'security' field of inodes according to the owned extended attribute set
with the function vfs_setxattr().  When this function is performed on a
ecryptfs filesystem the 'security' field is not updated for the lower
filesystem since the call security_inode_post_setxattr() is missing for
the lower inode.
Further, the call security_inode_setxattr() is missing for the lower inode,
leading to policy violations in the security module because specific
checks for this hook are not performed (i. e. filesystem
'associate' permission on SELinux is not checked for the lower filesystem).

This patch replaces the call of the setxattr() method of the lower inode
in the function ecryptfs_setxattr() with vfs_setxattr().

Signed-off-by: Roberto Sassu 
Cc: Dustin Kirkland 
Acked-by: James Morris 
Signed-off-by: Tyler Hicks 
Signed-off-by: Paul Gortmaker

eCryptfs: Extend array bounds for all filename chars

2013-01-16T21:44:57+00:00

commit 0f751e641a71157aa584c2a2e22fda52b52b8a56 upstream.

From mhalcrow's original commit message:

    Characters with ASCII values greater than the size of
    filename_rev_map[] are valid filename characters.
    ecryptfs_decode_from_filename() will access kernel memory beyond
    that array, and ecryptfs_parse_tag_70_packet() will then decrypt
    those characters. The attacker, using the FNEK of the crafted file,
    can then re-encrypt the characters to reveal the kernel memory past
    the end of the filename_rev_map[] array. I expect low security
    impact since this array is statically allocated in the text area,
    and the amount of memory past the array that is accessible is
    limited by the largest possible ASCII filename character.

This patch solves the issue reported by mhalcrow but with an
implementation suggested by Linus to simply extend the length of
filename_rev_map[] to 256. Characters greater than 0x7A are mapped to
0x00, which is how invalid characters less than 0x7A were previously
being handled.

Signed-off-by: Tyler Hicks 
Reported-by: Michael Halcrow 
Signed-off-by: Paul Gortmaker

eCryptfs: Allow 2 scatterlist entries for encrypted filenames

2012-05-17T15:20:37+00:00

commit 8d08dab786ad5cc2aca2bf870de370144b78c85a upstream.

The buffers allocated while encrypting and decrypting long filenames can
sometimes straddle two pages. In this situation, virt_to_scatterlist()
will return -ENOMEM, causing the operation to fail and the user will get
scary error messages in their logs:

kernel: ecryptfs_write_tag_70_packet: Internal error whilst attempting
to convert filename memory to scatterlist; expected rc = 1; got rc =
[-12]. block_aligned_filename_size = [272]
kernel: ecryptfs_encrypt_filename: Error attempting to generate tag 70
packet; rc = [-12]
kernel: ecryptfs_encrypt_and_encode_filename: Error attempting to
encrypt filename; rc = [-12]
kernel: ecryptfs_lookup: Error attempting to encrypt and encode
filename; rc = [-12]

The solution is to allow up to 2 scatterlist entries to be used.

Signed-off-by: Tyler Hicks 
Signed-off-by: Paul Gortmaker

eCryptfs: ecryptfs_keyring_auth_tok_for_sig() bug fix

2012-03-14T14:56:53+00:00

commit 1821df040ac3cd6a57518739f345da6d50ea9d3f upstream.

The pointer '(*auth_tok_key)' is set to NULL in case request_key()
fails, in order to prevent its use by functions calling
ecryptfs_keyring_auth_tok_for_sig().

Signed-off-by: Roberto Sassu 
Signed-off-by: Tyler Hicks 
Signed-off-by: Paul Gortmaker

eCryptfs: Unlock page in write_begin error path

2012-03-14T14:56:53+00:00

commit 50f198ae16ac66508d4b8d5a40967a8507ad19ee upstream.

Unlock the page in error path of ecryptfs_write_begin(). This may
happen, for example, if decryption fails while bring the page
up-to-date.

Signed-off-by: Tyler Hicks 
Signed-off-by: Paul Gortmaker

eCryptfs: Copy up lower inode attrs in getattr

2011-06-26T16:46:46+00:00

commit 55f9cf6bbaa682958a7dd2755f883b768270c3ce upstream.

The lower filesystem may do some type of inode revalidation during a
getattr call. eCryptfs should take advantage of that by copying the
lower inode attributes to the eCryptfs inode after a call to
vfs_getattr() on the lower inode.

I originally wrote this fix while working on eCryptfs on nfsv3 support,
but discovered it also fixed an eCryptfs on ext4 nanosecond timestamp
bug that was reported.

https://bugs.launchpad.net/bugs/613873

Signed-off-by: Tyler Hicks 
Signed-off-by: Paul Gortmaker

eCryptfs: Clear LOOKUP_OPEN flag when creating lower file

2011-04-17T20:15:42+00:00

commit 2e21b3f124eceb6ab5a07c8a061adce14ac94e14 upstream.

eCryptfs was passing the LOOKUP_OPEN flag through to the lower file
system, even though ecryptfs_create() doesn't support the flag. A valid
filp for the lower filesystem could be returned in the nameidata if the
lower file system's create() function supported LOOKUP_OPEN, possibly
resulting in unencrypted writes to the lower file.

However, this is only a potential problem in filesystems (FUSE, NFS,
CIFS, CEPH, 9p) that eCryptfs isn't known to support today.

https://bugs.launchpad.net/ecryptfs/+bug/641703

Reported-by: Kevin Buhr
Signed-off-by: Tyler Hicks 
Signed-off-by: Paul Gortmaker

fs/ecryptfs/file.c: introduce missing free

2010-08-13T20:27:21+00:00

commit ceeab92971e8af05c1e81a4ff2c271124b55bb9b upstream.

The comments in the code indicate that file_info should be released if the
function fails.  This releasing is done at the label out_free, not out.

The semantic match that finds this problem is as follows:
(http://www.emn.fr/x-info/coccinelle/)

// 
@r exists@
local idexpression x;
statement S;
expression E;
identifier f,f1,l;
position p1,p2;
expression *ptr != NULL;
@@

x@p1 = kmem_cache_zalloc(...);
...
if (x == NULL) S
<... when != x
     when != if (...) { <+...x...+> }
(
x->f1 = E
|
 (x->f1 == NULL || ...)
|
 f(...,x->f1,...)
)
...>
(
 return <+...x...+>;
|
 return@p2 ...;
)

@script:python@
p1 << r.p1;
p2 << r.p2;
@@

print "* file: %s kmem_cache_zalloc %s" % (p1[0].file,p1[0].line)
// 

Signed-off-by: Julia Lawall 
Signed-off-by: Tyler Hicks 
Signed-off-by: Greg Kroah-Hartman