This is a seriously simplified patch from Eric Sandeen; copy of
rationale follows:
===
mounting stacked ecryptfs on ecryptfs has been shown to lead to bugs
in testing. For crypto info in xattr, there is no mechanism for handling
this at all, and for normal file headers, we run into other trouble:
BUG: unable to handle kernel NULL pointer dereference at 0000000000000008
IP: [<ffffffffa015b0b3>] ecryptfs_d_revalidate+0x43/0xa0 [ecryptfs]
...
There doesn't seem to be any good usecase for this, so I'd suggest just
disallowing the configuration.
Based on a patch originally, I believe, from Mike Halcrow.
===
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Now that the last user passing a NULL file pointer is gone we can remove
the redundant dentry argument and associated hacks inside vfs_fsynmc_range.
The next step will be removig the dentry argument from ->fsync, but given
the luck with the last round of method prototype changes I'd rather
defer this until after the main merge window.
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
Vaugue warnings about ENAMETOOLONG errors when looking up an encrypted
file name have caused many users to become concerned about their data.
Since this is a rather harmless condition, I'm moving this warning to
only be printed when the ecryptfs_verbosity module param is 1.
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
The timestamps and size of a lower inode involved in a link() call was
being copied to the upper parent inode. Instead, we should be
copying lower parent inode's timestamps and size to the upper parent
inode. I discovered this bug using the POSIX test suite at Tuxera.
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
Since tmpfs has no persistent storage, it pins all its dentries in memory
so they have d_count=1 when other file systems would have d_count=0.
->lookup is only used to create new dentries. If the caller doesn't
instantiate it, it's freed immediately at dput(). ->readdir reads
directly from the dcache and depends on the dentries being hashed.
When an ecryptfs mount is mounted, it associates the lower file and dentry
with the ecryptfs files as they're accessed. When it's umounted and
destroys all the in-memory ecryptfs inodes, it fput's the lower_files and
d_drop's the lower_dentries. Commit 4981e081 added this and a d_delete in
2008 and several months later commit caeeeecf removed the d_delete. I
believe the d_drop() needs to be removed as well.
The d_drop effectively hides any file that has been accessed via ecryptfs
from the underlying tmpfs since it depends on it being hashed for it to
be accessible. I've removed the d_drop on my development node and see no
ill effects with basic testing on both tmpfs and persistent storage.
As a side effect, after ecryptfs d_drops the dentries on tmpfs, tmpfs
BUGs on umount. This is due to the dentries being unhashed.
tmpfs->kill_sb is kill_litter_super which calls d_genocide to drop
the reference pinning the dentry. It skips unhashed and negative dentries,
but shrink_dcache_for_umount_subtree doesn't. Since those dentries
still have an elevated d_count, we get a BUG().
This patch removes the d_drop call and fixes both issues.
This issue was reported at:
https://bugzilla.novell.com/show_bug.cgi?id=567887
Reported-by: Árpád Bíró <biroa@demasz.hu>
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Cc: Dustin Kirkland <kirkland@canonical.com>
Cc: stable@kernel.org
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
If the lower file system driver has extended attributes disabled,
ecryptfs' own access functions return -ENOSYS instead of -EOPNOTSUPP.
This breaks execution of programs in the ecryptfs mount, since the
kernel expects the latter error when checking for security
capabilities in xattrs.
Signed-off-by: Christian Pulvermacher <pulvermacher@gmx.de>
Cc: stable@kernel.org
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
Create a getattr handler for eCryptfs symlinks that is capable of
reading the lower target and decrypting its path. Prior to this patch,
a stat's st_size field would represent the strlen of the encrypted path,
while readlink() would return the strlen of the decrypted path. This
could lead to confusion in some userspace applications, since the two
values should be equal.
https://bugs.launchpad.net/bugs/524919
Reported-by: Loïc Minier <loic.minier@canonical.com>
Cc: stable@kernel.org
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.
percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.
http://userweb.kernel.org/~tj/misc/slabh-sweep.py
The script does the followings.
* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.
* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.
* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.
The conversion was done in the following steps.
1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.
2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.
3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.
4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.
5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.
6. percpu.h was updated not to include slab.h.
7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).
* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig
8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.
Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
The ecryptfs_encrypted_view mount option provides a unified way of
viewing encrypted eCryptfs files. If the metadata is stored in a xattr,
the metadata is moved to the file header when the file is read inside
the eCryptfs mount. Because of this, we should strip the
ECRYPTFS_METADATA_IN_XATTR flag from the header's flag section. This
allows eCryptfs to treat the file as an eCryptfs file with a header
at the front.
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
We initially read in the first PAGE_CACHE_SIZE of a file to if the
eCryptfs header marker can be found. If it isn't found and
ecryptfs_xattr_metadata was given as a mount option, then the
user.ecryptfs xattr is read into the same buffer. Since the data from
the first page of the file wasn't cleared, it is possible that we think
we've found a second tag 3 or tag 1 packet and then error out after the
packet contents aren't as expected. This patch clears the buffer before
filling it with metadata from the user.ecryptfs xattr.
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
This patch renames the num_header_bytes_at_front variable to
metadata_size since it now contains the max size of the metadata.
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
Fixes regression in 8faece5f90
When using the ecryptfs_xattr_metadata mount option, eCryptfs stores the
metadata (normally stored at the front of the file) in the user.ecryptfs
xattr. This causes ecryptfs_crypt_stat.num_header_bytes_at_front to be
0, since there is no header data at the front of the file. This results
in too much memory being requested and ENOMEM being returned from
ecryptfs_write_metadata().
This patch fixes the problem by using the num_header_bytes_at_front
variable for specifying the max size of the metadata, despite whether it
is stored in the header or xattr.
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
The "full_alg_name" variable is used on a couple error paths, so we
shouldn't free it until the end.
Signed-off-by: Dan Carpenter <error27@gmail.com>
Cc: stable@kernel.org
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
The variable lower_dentry is initialized twice to the same (side effect-free)
expression. Drop one initialization.
A simplified version of the semantic match that finds this problem is:
(http://coccinelle.lip6.fr/)
// <smpl>
@forall@
idexpression *x;
identifier f!=ERR_PTR;
@@
x = f(...)
... when != x
(
x = f(...,<+...x...+>,...)
|
* x = f(...)
)
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
ecryptfs_interpose checks if one of the flags passed is
ECRYPTFS_INTERPOSE_FLAG_D_ADD, defined as 0x00000001 in ecryptfs_kernel.h.
But the only user of ecryptfs_interpose to pass a non-zero flag to it, has
hard-coded the value as "1". This could spell trouble if any of these values
changes in the future.
Signed-off-by: Erez Zadok <ezk@cs.sunysb.edu>
Cc: Dustin Kirkland <kirkland@canonical.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
Unnecessary because it would unhash perfectly valid dentries, causing them
to have to be re-looked up the next time they're needed, which presumably is
right after.
Signed-off-by: Aseem Rastogi <arastogi@cs.sunysb.edu>
Signed-off-by: Shrikar archak <shrikar84@gmail.com>
Signed-off-by: Erez Zadok <ezk@cs.sunysb.edu>
Cc: Saumitra Bhanage <sbhanage@cs.sunysb.edu>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
Ecryptfs_open dereferences a pointer to the private lower file (the one
stored in the ecryptfs inode), without checking if the pointer is NULL.
Right afterward, it initializes that pointer if it is NULL. Swap order of
statements to first initialize. Bug discovered by Duckjin Kang.
Signed-off-by: Duckjin Kang <fromdj2k@gmail.com>
Signed-off-by: Erez Zadok <ezk@cs.sunysb.edu>
Cc: Dustin Kirkland <kirkland@canonical.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: <stable@kernel.org>
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
Adrian reported that mkfontscale didn't work inside of eCryptfs mounts.
Strace revealed the following:
open("./", O_RDONLY|O_NONBLOCK|O_LARGEFILE|O_DIRECTORY|O_CLOEXEC) = 3
fcntl64(3, F_GETFD) = 0x1 (flags FD_CLOEXEC)
open("./fonts.scale", O_WRONLY|O_CREAT|O_TRUNC, 0666) = 4
getdents(3, /* 80 entries */, 32768) = 2304
open("./.", O_RDONLY) = 5
fcntl64(5, F_SETFD, FD_CLOEXEC) = 0
fstat64(5, {st_mode=S_IFDIR|0755, st_size=16384, ...}) = 0
mmap2(NULL, 16384, PROT_READ, MAP_PRIVATE, 5, 0) = 0xb7fcf000
close(5) = 0
--- SIGBUS (Bus error) @ 0 (0) ---
+++ killed by SIGBUS +++
The mmap2() on a directory was successful, resulting in a SIGBUS
signal later. This patch removes mmap() from the list of possible
ecryptfs_dir_fops so that mmap() isn't possible on eCryptfs directory
files.
https://bugs.launchpad.net/ecryptfs/+bug/400443
Reported-by: Adrian C. <anrxc@sysphere.org>
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
The i_blocks field of an eCryptfs inode cannot be trusted, but
generic_fillattr() uses it to instantiate the blocks field of a stat()
syscall when a filesystem doesn't implement its own getattr(). Users
have noticed that the output of du is incorrect on newly created files.
This patch creates ecryptfs_getattr() which calls into the lower
filesystem's getattr() so that eCryptfs can use its kstat.blocks value
after calling generic_fillattr(). It is important to note that the
block count includes the eCryptfs metadata stored in the beginning of
the lower file plus any padding used to fill an extent before
encryption.
https://bugs.launchpad.net/ecryptfs/+bug/390833
Reported-by: Dominic Sacré <dominic.sacre@gmx.de>
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
When truncating inodes in the lower filesystem, eCryptfs directly
invoked vmtruncate(). As Christoph Hellwig pointed out, vmtruncate() is
a filesystem helper function, but filesystems may need to do more than
just a call to vmtruncate().
This patch moves the lower inode truncation out of ecryptfs_truncate()
and renames the function to truncate_upper(). truncate_upper() updates
an iattr for the lower inode to indicate if the lower inode needs to be
truncated upon return. ecryptfs_setattr() then calls notify_change(),
using the updated iattr for the lower inode, to complete the truncation.
For eCryptfs functions needing to truncate, ecryptfs_truncate() is
reintroduced as a simple way to truncate the upper inode to a specified
size and then truncate the lower inode accordingly.
https://bugs.launchpad.net/bugs/451368
Reported-by: Christoph Hellwig <hch@lst.de>
Acked-by: Dustin Kirkland <kirkland@canonical.com>
Cc: ecryptfs-devel@lists.launchpad.net
Cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
If ->follow_link handler return the error, it should decrement
nd->path refcnt. But, ecryptfs_follow_link() doesn't decrement.
This patch fix it by using usual nd_set_link() style error handling,
instead of playing with nd->path.
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This get_nlinks parameter was never used by the only mainline user,
ecryptfs; and it has never been used by unionfs or wrapfs either.
Acked-by: Dustin Kirkland <kirkland@canonical.com>
Acked-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
Signed-off-by: Erez Zadok <ezk@cs.sunysb.edu>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* do ima_get_count() in __dentry_open()
* stop doing that in followups
* move ima_path_check() to right after nameidata_to_filp()
* don't bump counters on it
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
The unencrypted files are being measured. Update the counters to get
rid of the ecryptfs imbalance message. (http://bugzilla.redhat.com/519737)
Reported-by: Sachin Garg
Cc: Eric Paris <eparis@redhat.com>
Cc: Dustin Kirkland <kirkland@canonical.com>
Cc: James Morris <jmorris@namei.org>
Cc: David Safford <safford@watson.ibm.com>
Cc: stable@kernel.org
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
eCryptfs no longer uses a netlink interface to communicate with
ecryptfsd, so NET is not a valid dependency anymore.
MD5 is required and must be built for eCryptfs to be of any use.
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
ecryptfs uses crypto APIs so it should depend on CRYPTO.
Otherwise many build errors occur. [63 lines not pasted]
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: ecryptfs-devel@lists.launchpad.net
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
When calling vfs_unlink() on the lower dentry, d_delete() turns the
dentry into a negative dentry when the d_count is 1. This eventually
caused a NULL pointer deref when a read() or write() was done and the
negative dentry's d_inode was dereferenced in
ecryptfs_read_update_atime() or ecryptfs_getxattr().
Placing mutt's tmpdir in an eCryptfs mount is what initially triggered
the oops and I was able to reproduce it with the following sequence:
open("/tmp/upper/foo", O_RDWR|O_CREAT|O_EXCL|O_NOFOLLOW, 0600) = 3
link("/tmp/upper/foo", "/tmp/upper/bar") = 0
unlink("/tmp/upper/foo") = 0
open("/tmp/upper/bar", O_RDWR|O_CREAT|O_NOFOLLOW, 0600) = 4
unlink("/tmp/upper/bar") = 0
write(4, "eCryptfs test\n"..., 14 <unfinished ...>
+++ killed by SIGKILL +++
https://bugs.launchpad.net/ecryptfs/+bug/387073
Reported-by: Loïc Minier <loic.minier@canonical.com>
Cc: Serge Hallyn <serue@us.ibm.com>
Cc: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Cc: ecryptfs-devel@lists.launchpad.net
Cc: stable <stable@kernel.org>
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
Errors returned from vfs_read() and vfs_write() calls to the lower
filesystem were being masked as -EINVAL. This caused some confusion to
users who saw EINVAL instead of ENOSPC when the disk was full, for
instance.
Also, the actual bytes read or written were not accessible by callers to
ecryptfs_read_lower() and ecryptfs_write_lower(), which may be useful in
some cases. This patch updates the error handling logic where those
functions are called in order to accept positive return codes indicating
success.
Cc: Eric Sandeen <esandeen@redhat.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Cc: ecryptfs-devel@lists.launchpad.net
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
When searching through the global authentication tokens for a given key
signature, verify that a matching key has not been revoked and has not
expired. This allows the `keyctl revoke` command to be properly used on
keys in use by eCryptfs.
Acked-by: Serge Hallyn <serue@us.ibm.com>
Cc: ecryptfs-devel@lists.launchpad.net
Cc: stable <stable@kernel.org>
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
Returns -ENOTSUPP when attempting to use filename encryption with
something other than a password authentication token, such as a private
token from openssl. Using filename encryption with a userspace eCryptfs
key module is a future goal. Until then, this patch handles the
situation a little better than simply using a BUG_ON().
Acked-by: Serge Hallyn <serue@us.ibm.com>
Cc: ecryptfs-devel@lists.launchpad.net
Cc: stable <stable@kernel.org>
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
If the lower inode is read-only, don't attempt to open the lower file
read/write and don't hand off the open request to the privileged
eCryptfs kthread for opening it read/write. Instead, only try an
unprivileged, read-only open of the file and give up if that fails.
This patch fixes an oops when eCryptfs is mounted on top of a read-only
mount.
Acked-by: Serge Hallyn <serue@us.ibm.com>
Cc: Eric Sandeen <esandeen@redhat.com>
Cc: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Cc: ecryptfs-devel@lists.launchpad.net
Cc: stable <stable@kernel.org>
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
Returns an error when an unrecognized cipher code is present in a tag 3
packet or an ecryptfs_crypt_stat cannot be initialized. Also sets an
crypt_stat->tfm error pointer to NULL to ensure that it will not be
incorrectly freed in ecryptfs_destroy_crypt_stat().
Acked-by: Serge Hallyn <serue@us.ibm.com>
Cc: ecryptfs-devel@lists.launchpad.net
Cc: stable <stable@kernel.org>
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
So, I compiled a 2.6.31-rc5 kernel with ecryptfs and loaded its module.
When it came time to mount my filesystem, I got this in dmesg, and it
refused to mount:
[93577.776637] Unable to allocate crypto cipher with name [aes]; rc = [-2]
[93577.783280] Error attempting to initialize key TFM cipher with name = [aes]; rc = [-2]
[93577.791183] Error attempting to initialize cipher with name = [aes] and key size = [32]; rc = [-2]
[93577.800113] Error parsing options; rc = [-22]
I figured from the error message that I'd either forgotten to load "aes"
or that my key size was bogus. Neither one of those was the case. In
fact, I was missing the CRYPTO_ECB config option and the 'ecb' module.
Unfortunately, there's no trace of 'ecb' in that error message.
I've done two things to fix this. First, I've modified ecryptfs's
Kconfig entry to select CRYPTO_ECB and CRYPTO_CBC. I also took CRYPTO
out of the dependencies since the 'select' will take care of it for us.
I've also modified the error messages to print a string that should
contain both 'ecb' and 'aes' in my error case. That will give any
future users a chance of finding the right modules and Kconfig options.
I also wonder if we should:
select CRYPTO_AES if !EMBEDDED
since I think most ecryptfs users are using AES like me.
Cc: ecryptfs-devel@lists.launchpad.net
Cc: linux-fsdevel@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: Dustin Kirkland <kirkland@canonical.com>
Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com>
[tyhicks@linux.vnet.ibm.com: Removed extra newline, 80-char violation]
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
Lockdep reports the following valid-looking possible AB-BA deadlock with
global_auth_tok_list_mutex and keysig_list_mutex:
ecryptfs_new_file_context() ->
ecryptfs_copy_mount_wide_sigs_to_inode_sigs() ->
mutex_lock(&mount_crypt_stat->global_auth_tok_list_mutex);
-> ecryptfs_add_keysig() ->
mutex_lock(&crypt_stat->keysig_list_mutex);
vs
ecryptfs_generate_key_packet_set() ->
mutex_lock(&crypt_stat->keysig_list_mutex);
-> ecryptfs_find_global_auth_tok_for_sig() ->
mutex_lock(&mount_crypt_stat->global_auth_tok_list_mutex);
ie the two mutexes are taken in opposite orders in the two different
code paths. I'm not sure if this is a real bug where two threads could
actually hit the two paths in parallel and deadlock, but it at least
makes lockdep impossible to use with ecryptfs since this report triggers
every time and disables future lockdep reporting.
Since ecryptfs_add_keysig() is called only from the single callsite in
ecryptfs_copy_mount_wide_sigs_to_inode_sigs(), the simplest fix seems to
be to move the lock of keysig_list_mutex back up outside of the where
global_auth_tok_list_mutex is taken. This patch does that, and fixes
the lockdep report on my system (and ecryptfs still works OK).
The full output of lockdep fixed by this patch is:
=======================================================
[ INFO: possible circular locking dependency detected ]
2.6.31-2-generic #14~rbd2
-------------------------------------------------------
gdm/2640 is trying to acquire lock:
(&mount_crypt_stat->global_auth_tok_list_mutex){+.+.+.}, at: [<ffffffff8121591e>] ecryptfs_find_global_auth_tok_for_sig+0x2e/0x90
but task is already holding lock:
(&crypt_stat->keysig_list_mutex){+.+.+.}, at: [<ffffffff81217728>] ecryptfs_generate_key_packet_set+0x58/0x2b0
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (&crypt_stat->keysig_list_mutex){+.+.+.}:
[<ffffffff8108c897>] check_prev_add+0x2a7/0x370
[<ffffffff8108cfc1>] validate_chain+0x661/0x750
[<ffffffff8108d2e7>] __lock_acquire+0x237/0x430
[<ffffffff8108d585>] lock_acquire+0xa5/0x150
[<ffffffff815526cd>] __mutex_lock_common+0x4d/0x3d0
[<ffffffff81552b56>] mutex_lock_nested+0x46/0x60
[<ffffffff8121526a>] ecryptfs_add_keysig+0x5a/0xb0
[<ffffffff81213299>] ecryptfs_copy_mount_wide_sigs_to_inode_sigs+0x59/0xb0
[<ffffffff81214b06>] ecryptfs_new_file_context+0xa6/0x1a0
[<ffffffff8120e42a>] ecryptfs_initialize_file+0x4a/0x140
[<ffffffff8120e54d>] ecryptfs_create+0x2d/0x60
[<ffffffff8113a7d4>] vfs_create+0xb4/0xe0
[<ffffffff8113a8c4>] __open_namei_create+0xc4/0x110
[<ffffffff8113d1c1>] do_filp_open+0xa01/0xae0
[<ffffffff8112d8d9>] do_sys_open+0x69/0x140
[<ffffffff8112d9f0>] sys_open+0x20/0x30
[<ffffffff81013132>] system_call_fastpath+0x16/0x1b
[<ffffffffffffffff>] 0xffffffffffffffff
-> #0 (&mount_crypt_stat->global_auth_tok_list_mutex){+.+.+.}:
[<ffffffff8108c675>] check_prev_add+0x85/0x370
[<ffffffff8108cfc1>] validate_chain+0x661/0x750
[<ffffffff8108d2e7>] __lock_acquire+0x237/0x430
[<ffffffff8108d585>] lock_acquire+0xa5/0x150
[<ffffffff815526cd>] __mutex_lock_common+0x4d/0x3d0
[<ffffffff81552b56>] mutex_lock_nested+0x46/0x60
[<ffffffff8121591e>] ecryptfs_find_global_auth_tok_for_sig+0x2e/0x90
[<ffffffff812177d5>] ecryptfs_generate_key_packet_set+0x105/0x2b0
[<ffffffff81212f49>] ecryptfs_write_headers_virt+0xc9/0x120
[<ffffffff8121306d>] ecryptfs_write_metadata+0xcd/0x200
[<ffffffff8120e44b>] ecryptfs_initialize_file+0x6b/0x140
[<ffffffff8120e54d>] ecryptfs_create+0x2d/0x60
[<ffffffff8113a7d4>] vfs_create+0xb4/0xe0
[<ffffffff8113a8c4>] __open_namei_create+0xc4/0x110
[<ffffffff8113d1c1>] do_filp_open+0xa01/0xae0
[<ffffffff8112d8d9>] do_sys_open+0x69/0x140
[<ffffffff8112d9f0>] sys_open+0x20/0x30
[<ffffffff81013132>] system_call_fastpath+0x16/0x1b
[<ffffffffffffffff>] 0xffffffffffffffff
other info that might help us debug this:
2 locks held by gdm/2640:
#0: (&sb->s_type->i_mutex_key#11){+.+.+.}, at: [<ffffffff8113cb8b>] do_filp_open+0x3cb/0xae0
#1: (&crypt_stat->keysig_list_mutex){+.+.+.}, at: [<ffffffff81217728>] ecryptfs_generate_key_packet_set+0x58/0x2b0
stack backtrace:
Pid: 2640, comm: gdm Tainted: G C 2.6.31-2-generic #14~rbd2
Call Trace:
[<ffffffff8108b988>] print_circular_bug_tail+0xa8/0xf0
[<ffffffff8108c675>] check_prev_add+0x85/0x370
[<ffffffff81094912>] ? __module_text_address+0x12/0x60
[<ffffffff8108cfc1>] validate_chain+0x661/0x750
[<ffffffff81017275>] ? print_context_stack+0x85/0x140
[<ffffffff81089c68>] ? find_usage_backwards+0x38/0x160
[<ffffffff8108d2e7>] __lock_acquire+0x237/0x430
[<ffffffff8108d585>] lock_acquire+0xa5/0x150
[<ffffffff8121591e>] ? ecryptfs_find_global_auth_tok_for_sig+0x2e/0x90
[<ffffffff8108b0b0>] ? check_usage_backwards+0x0/0xb0
[<ffffffff815526cd>] __mutex_lock_common+0x4d/0x3d0
[<ffffffff8121591e>] ? ecryptfs_find_global_auth_tok_for_sig+0x2e/0x90
[<ffffffff8121591e>] ? ecryptfs_find_global_auth_tok_for_sig+0x2e/0x90
[<ffffffff8108c02c>] ? mark_held_locks+0x6c/0xa0
[<ffffffff81125b0d>] ? kmem_cache_alloc+0xfd/0x1a0
[<ffffffff8108c34d>] ? trace_hardirqs_on_caller+0x14d/0x190
[<ffffffff81552b56>] mutex_lock_nested+0x46/0x60
[<ffffffff8121591e>] ecryptfs_find_global_auth_tok_for_sig+0x2e/0x90
[<ffffffff812177d5>] ecryptfs_generate_key_packet_set+0x105/0x2b0
[<ffffffff81212f49>] ecryptfs_write_headers_virt+0xc9/0x120
[<ffffffff8121306d>] ecryptfs_write_metadata+0xcd/0x200
[<ffffffff81210240>] ? ecryptfs_init_persistent_file+0x60/0xe0
[<ffffffff8120e44b>] ecryptfs_initialize_file+0x6b/0x140
[<ffffffff8120e54d>] ecryptfs_create+0x2d/0x60
[<ffffffff8113a7d4>] vfs_create+0xb4/0xe0
[<ffffffff8113a8c4>] __open_namei_create+0xc4/0x110
[<ffffffff8113d1c1>] do_filp_open+0xa01/0xae0
[<ffffffff8129a93e>] ? _raw_spin_unlock+0x5e/0xb0
[<ffffffff8155410b>] ? _spin_unlock+0x2b/0x40
[<ffffffff81139e9b>] ? getname+0x3b/0x240
[<ffffffff81148a5a>] ? alloc_fd+0xfa/0x140
[<ffffffff8112d8d9>] do_sys_open+0x69/0x140
[<ffffffff81553b8f>] ? trace_hardirqs_on_thunk+0x3a/0x3f
[<ffffffff8112d9f0>] sys_open+0x20/0x30
[<ffffffff81013132>] system_call_fastpath+0x16/0x1b
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
In ecryptfs_destroy_inode(), inode_info->lower_file_mutex is locked,
and just after the mutex is unlocked, the code does:
kmem_cache_free(ecryptfs_inode_info_cache, inode_info);
This means that if another context could possibly try to take the same
mutex as ecryptfs_destroy_inode(), then it could end up getting the
mutex just before the data structure containing the mutex is freed.
So any such use would be an obvious use-after-free bug (catchable with
slab poisoning or mutex debugging), and therefore the locking in
ecryptfs_destroy_inode() is not needed and can be dropped.
Similarly, in ecryptfs_destroy_crypt_stat(), crypt_stat->keysig_list_mutex
is locked, and then the mutex is unlocked just before the code does:
memset(crypt_stat, 0, sizeof(struct ecryptfs_crypt_stat));
Therefore taking this mutex is similarly not necessary.
Removing this locking fixes false-positive lockdep reports such as the
following (and they are false-positives for exactly the same reason
that the locking is not needed):
=================================
[ INFO: inconsistent lock state ]
2.6.31-2-generic #14~rbd3
---------------------------------
inconsistent {RECLAIM_FS-ON-W} -> {IN-RECLAIM_FS-W} usage.
kswapd0/323 [HC0[0]:SC0[0]:HE1:SE1] takes:
(&inode_info->lower_file_mutex){+.+.?.}, at: [<ffffffff81210d34>] ecryptfs_destroy_inode+0x34/0x100
{RECLAIM_FS-ON-W} state was registered at:
[<ffffffff8108c02c>] mark_held_locks+0x6c/0xa0
[<ffffffff8108c10f>] lockdep_trace_alloc+0xaf/0xe0
[<ffffffff81125a51>] kmem_cache_alloc+0x41/0x1a0
[<ffffffff8113117a>] get_empty_filp+0x7a/0x1a0
[<ffffffff8112dd46>] dentry_open+0x36/0xc0
[<ffffffff8121a36c>] ecryptfs_privileged_open+0x5c/0x2e0
[<ffffffff81210283>] ecryptfs_init_persistent_file+0xa3/0xe0
[<ffffffff8120e838>] ecryptfs_lookup_and_interpose_lower+0x278/0x380
[<ffffffff8120f97a>] ecryptfs_lookup+0x12a/0x250
[<ffffffff8113930a>] real_lookup+0xea/0x160
[<ffffffff8113afc8>] do_lookup+0xb8/0xf0
[<ffffffff8113b518>] __link_path_walk+0x518/0x870
[<ffffffff8113bd9c>] path_walk+0x5c/0xc0
[<ffffffff8113be5b>] do_path_lookup+0x5b/0xa0
[<ffffffff8113bfe7>] user_path_at+0x57/0xa0
[<ffffffff811340dc>] vfs_fstatat+0x3c/0x80
[<ffffffff8113424b>] vfs_stat+0x1b/0x20
[<ffffffff81134274>] sys_newstat+0x24/0x50
[<ffffffff81013132>] system_call_fastpath+0x16/0x1b
[<ffffffffffffffff>] 0xffffffffffffffff
irq event stamp: 7811
hardirqs last enabled at (7811): [<ffffffff810c037f>] call_rcu+0x5f/0x90
hardirqs last disabled at (7810): [<ffffffff810c0353>] call_rcu+0x33/0x90
softirqs last enabled at (3764): [<ffffffff810631da>] __do_softirq+0x14a/0x220
softirqs last disabled at (3751): [<ffffffff8101440c>] call_softirq+0x1c/0x30
other info that might help us debug this:
2 locks held by kswapd0/323:
#0: (shrinker_rwsem){++++..}, at: [<ffffffff810f67ed>] shrink_slab+0x3d/0x190
#1: (&type->s_umount_key#35){.+.+..}, at: [<ffffffff811429a1>] prune_dcache+0xd1/0x1b0
stack backtrace:
Pid: 323, comm: kswapd0 Tainted: G C 2.6.31-2-generic #14~rbd3
Call Trace:
[<ffffffff8108ad6c>] print_usage_bug+0x18c/0x1a0
[<ffffffff8108aff0>] ? check_usage_forwards+0x0/0xc0
[<ffffffff8108bac2>] mark_lock_irq+0xf2/0x280
[<ffffffff8108bd87>] mark_lock+0x137/0x1d0
[<ffffffff81164710>] ? fsnotify_clear_marks_by_inode+0x30/0xf0
[<ffffffff8108bee6>] mark_irqflags+0xc6/0x1a0
[<ffffffff8108d337>] __lock_acquire+0x287/0x430
[<ffffffff8108d585>] lock_acquire+0xa5/0x150
[<ffffffff81210d34>] ? ecryptfs_destroy_inode+0x34/0x100
[<ffffffff8108d2e7>] ? __lock_acquire+0x237/0x430
[<ffffffff815526ad>] __mutex_lock_common+0x4d/0x3d0
[<ffffffff81210d34>] ? ecryptfs_destroy_inode+0x34/0x100
[<ffffffff81164710>] ? fsnotify_clear_marks_by_inode+0x30/0xf0
[<ffffffff81210d34>] ? ecryptfs_destroy_inode+0x34/0x100
[<ffffffff8129a91e>] ? _raw_spin_unlock+0x5e/0xb0
[<ffffffff81552b36>] mutex_lock_nested+0x46/0x60
[<ffffffff81210d34>] ecryptfs_destroy_inode+0x34/0x100
[<ffffffff81145d27>] destroy_inode+0x87/0xd0
[<ffffffff81146b4c>] generic_delete_inode+0x12c/0x1a0
[<ffffffff81145832>] iput+0x62/0x70
[<ffffffff811423c8>] dentry_iput+0x98/0x110
[<ffffffff81142550>] d_kill+0x50/0x80
[<ffffffff81142623>] prune_one_dentry+0xa3/0xc0
[<ffffffff811428b1>] __shrink_dcache_sb+0x271/0x290
[<ffffffff811429d9>] prune_dcache+0x109/0x1b0
[<ffffffff81142abf>] shrink_dcache_memory+0x3f/0x50
[<ffffffff810f68dd>] shrink_slab+0x12d/0x190
[<ffffffff810f9377>] balance_pgdat+0x4d7/0x640
[<ffffffff8104c4c0>] ? finish_task_switch+0x40/0x150
[<ffffffff810f63c0>] ? isolate_pages_global+0x0/0x60
[<ffffffff810f95f7>] kswapd+0x117/0x170
[<ffffffff810777a0>] ? autoremove_wake_function+0x0/0x40
[<ffffffff810f94e0>] ? kswapd+0x0/0x170
[<ffffffff810773be>] kthread+0x9e/0xb0
[<ffffffff8101430a>] child_rip+0xa/0x20
[<ffffffff81013c90>] ? restore_args+0x0/0x30
[<ffffffff81077320>] ? kthread+0x0/0xb0
[<ffffffff81014300>] ? child_rip+0x0/0x20
Signed-off-by: Roland Dreier <roland@digitalvampire.org>
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
The parse_tag_3_packet function does not check if the tag 3 packet contains a
encrypted key size larger than ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES.
Signed-off-by: Ramon de Carvalho Valle <ramon@risesecurity.org>
[tyhicks@linux.vnet.ibm.com: Added printk newline and changed goto to out_free]
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
Cc: stable@kernel.org (2.6.27 and 30)
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Tag 11 packets are stored in the metadata section of an eCryptfs file to
store the key signature(s) used to encrypt the file encryption key.
After extracting the packet length field to determine the key signature
length, a check is not performed to see if the length would exceed the
key signature buffer size that was passed into parse_tag_11_packet().
Thanks to Ramon de Carvalho Valle for finding this bug using fsfuzzer.
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
Cc: stable@kernel.org (2.6.27 and 30)
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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>
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>
