Commit Graph

490 Commits

Author SHA1 Message Date
Kees Cook
290502bee2 eCryptfs: allow userspace messaging to be disabled
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>
2013-03-03 23:59:59 -08:00
Eric W. Biederman
7f78e03513 fs: Limit sys_mount to only request filesystem modules.
Modify the request_module to prefix the file system type with "fs-"
and add aliases to all of the filesystems that can be built as modules
to match.

A common practice is to build all of the kernel code and leave code
that is not commonly needed as modules, with the result that many
users are exposed to any bug anywhere in the kernel.

Looking for filesystems with a fs- prefix limits the pool of possible
modules that can be loaded by mount to just filesystems trivially
making things safer with no real cost.

Using aliases means user space can control the policy of which
filesystem modules are auto-loaded by editing /etc/modprobe.d/*.conf
with blacklist and alias directives.  Allowing simple, safe,
well understood work-arounds to known problematic software.

This also addresses a rare but unfortunate problem where the filesystem
name is not the same as it's module name and module auto-loading
would not work.  While writing this patch I saw a handful of such
cases.  The most significant being autofs that lives in the module
autofs4.

This is relevant to user namespaces because we can reach the request
module in get_fs_type() without having any special permissions, and
people get uncomfortable when a user specified string (in this case
the filesystem type) goes all of the way to request_module.

After having looked at this issue I don't think there is any
particular reason to perform any filtering or permission checks beyond
making it clear in the module request that we want a filesystem
module.  The common pattern in the kernel is to call request_module()
without regards to the users permissions.  In general all a filesystem
module does once loaded is call register_filesystem() and go to sleep.
Which means there is not much attack surface exposed by loading a
filesytem module unless the filesystem is mounted.  In a user
namespace filesystems are not mounted unless .fs_flags = FS_USERNS_MOUNT,
which most filesystems do not set today.

Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Acked-by: Kees Cook <keescook@chromium.org>
Reported-by: Kees Cook <keescook@google.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2013-03-03 19:36:31 -08:00
Sasha Levin
b67bfe0d42 hlist: drop the node parameter from iterators
I'm not sure why, but the hlist for each entry iterators were conceived

        list_for_each_entry(pos, head, member)

The hlist ones were greedy and wanted an extra parameter:

        hlist_for_each_entry(tpos, pos, head, member)

Why did they need an extra pos parameter? I'm not quite sure. Not only
they don't really need it, it also prevents the iterator from looking
exactly like the list iterator, which is unfortunate.

Besides the semantic patch, there was some manual work required:

 - Fix up the actual hlist iterators in linux/list.h
 - Fix up the declaration of other iterators based on the hlist ones.
 - A very small amount of places were using the 'node' parameter, this
 was modified to use 'obj->member' instead.
 - Coccinelle didn't handle the hlist_for_each_entry_safe iterator
 properly, so those had to be fixed up manually.

The semantic patch which is mostly the work of Peter Senna Tschudin is here:

@@
iterator name hlist_for_each_entry, hlist_for_each_entry_continue, hlist_for_each_entry_from, hlist_for_each_entry_rcu, hlist_for_each_entry_rcu_bh, hlist_for_each_entry_continue_rcu_bh, for_each_busy_worker, ax25_uid_for_each, ax25_for_each, inet_bind_bucket_for_each, sctp_for_each_hentry, sk_for_each, sk_for_each_rcu, sk_for_each_from, sk_for_each_safe, sk_for_each_bound, hlist_for_each_entry_safe, hlist_for_each_entry_continue_rcu, nr_neigh_for_each, nr_neigh_for_each_safe, nr_node_for_each, nr_node_for_each_safe, for_each_gfn_indirect_valid_sp, for_each_gfn_sp, for_each_host;

type T;
expression a,c,d,e;
identifier b;
statement S;
@@

-T b;
    <+... when != b
(
hlist_for_each_entry(a,
- b,
c, d) S
|
hlist_for_each_entry_continue(a,
- b,
c) S
|
hlist_for_each_entry_from(a,
- b,
c) S
|
hlist_for_each_entry_rcu(a,
- b,
c, d) S
|
hlist_for_each_entry_rcu_bh(a,
- b,
c, d) S
|
hlist_for_each_entry_continue_rcu_bh(a,
- b,
c) S
|
for_each_busy_worker(a, c,
- b,
d) S
|
ax25_uid_for_each(a,
- b,
c) S
|
ax25_for_each(a,
- b,
c) S
|
inet_bind_bucket_for_each(a,
- b,
c) S
|
sctp_for_each_hentry(a,
- b,
c) S
|
sk_for_each(a,
- b,
c) S
|
sk_for_each_rcu(a,
- b,
c) S
|
sk_for_each_from
-(a, b)
+(a)
S
+ sk_for_each_from(a) S
|
sk_for_each_safe(a,
- b,
c, d) S
|
sk_for_each_bound(a,
- b,
c) S
|
hlist_for_each_entry_safe(a,
- b,
c, d, e) S
|
hlist_for_each_entry_continue_rcu(a,
- b,
c) S
|
nr_neigh_for_each(a,
- b,
c) S
|
nr_neigh_for_each_safe(a,
- b,
c, d) S
|
nr_node_for_each(a,
- b,
c) S
|
nr_node_for_each_safe(a,
- b,
c, d) S
|
- for_each_gfn_sp(a, c, d, b) S
+ for_each_gfn_sp(a, c, d) S
|
- for_each_gfn_indirect_valid_sp(a, c, d, b) S
+ for_each_gfn_indirect_valid_sp(a, c, d) S
|
for_each_host(a,
- b,
c) S
|
for_each_host_safe(a,
- b,
c, d) S
|
for_each_mesh_entry(a,
- b,
c, d) S
)
    ...+>

[akpm@linux-foundation.org: drop bogus change from net/ipv4/raw.c]
[akpm@linux-foundation.org: drop bogus hunk from net/ipv6/raw.c]
[akpm@linux-foundation.org: checkpatch fixes]
[akpm@linux-foundation.org: fix warnings]
[akpm@linux-foudnation.org: redo intrusive kvm changes]
Tested-by: Peter Senna Tschudin <peter.senna@gmail.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-27 19:10:24 -08:00
Tyler Hicks
1111eae90f eCryptfs: Fix redundant error check on ecryptfs_find_daemon_by_euid()
It is sufficient to check the return code of
ecryptfs_find_daemon_by_euid(). If it returns 0, it always sets the
daemon pointer to point to a valid ecryptfs_daemon.

Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Reported-by: Kees Cook <keescook@chromium.org>
2013-02-27 11:41:18 -08:00
Linus Torvalds
d895cb1af1 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs pile (part one) from Al Viro:
 "Assorted stuff - cleaning namei.c up a bit, fixing ->d_name/->d_parent
  locking violations, etc.

  The most visible changes here are death of FS_REVAL_DOT (replaced with
  "has ->d_weak_revalidate()") and a new helper getting from struct file
  to inode.  Some bits of preparation to xattr method interface changes.

  Misc patches by various people sent this cycle *and* ocfs2 fixes from
  several cycles ago that should've been upstream right then.

  PS: the next vfs pile will be xattr stuff."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (46 commits)
  saner proc_get_inode() calling conventions
  proc: avoid extra pde_put() in proc_fill_super()
  fs: change return values from -EACCES to -EPERM
  fs/exec.c: make bprm_mm_init() static
  ocfs2/dlm: use GFP_ATOMIC inside a spin_lock
  ocfs2: fix possible use-after-free with AIO
  ocfs2: Fix oops in ocfs2_fast_symlink_readpage() code path
  get_empty_filp()/alloc_file() leave both ->f_pos and ->f_version zero
  target: writev() on single-element vector is pointless
  export kernel_write(), convert open-coded instances
  fs: encode_fh: return FILEID_INVALID if invalid fid_type
  kill f_vfsmnt
  vfs: kill FS_REVAL_DOT by adding a d_weak_revalidate dentry op
  nfsd: handle vfs_getattr errors in acl protocol
  switch vfs_getattr() to struct path
  default SET_PERSONALITY() in linux/elf.h
  ceph: prepopulate inodes only when request is aborted
  d_hash_and_lookup(): export, switch open-coded instances
  9p: switch v9fs_set_create_acl() to inode+fid, do it before d_instantiate()
  9p: split dropping the acls from v9fs_set_create_acl()
  ...
2013-02-26 20:16:07 -08:00
Al Viro
7bb307e894 export kernel_write(), convert open-coded instances
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-02-26 02:46:11 -05:00
Al Viro
3dadecce20 switch vfs_getattr() to struct path
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-02-26 02:46:08 -05:00
Al Viro
496ad9aa8e new helper: file_inode(file)
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-02-22 23:31:31 -05:00
Tim Gardner
1101d58669 ecryptfs: ecryptfs_msg_ctx_alloc_to_free(): remove kfree() redundant null check
smatch analysis:

fs/ecryptfs/messaging.c:101 ecryptfs_msg_ctx_alloc_to_free() info:
 redundant null check on msg_ctx->msg calling kfree()

Cc: Dustin Kirkland <dustin.kirkland@gazzang.com>
Cc: ecryptfs@vger.kernel.org
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
2013-02-12 10:09:11 -08:00
Tim Gardner
3a46741804 eCryptfs: decrypt_pki_encrypted_session_key(): remove kfree() redundant null check
smatch analysis:

fs/ecryptfs/keystore.c:1206 decrypt_pki_encrypted_session_key() info:
 redundant null check on msg calling kfree()

Cc: Dustin Kirkland <dustin.kirkland@gazzang.com>
Cc: ecryptfs@vger.kernel.org
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
2013-02-12 10:06:01 -08:00
Dan Carpenter
a07c48ad5b eCryptfs: remove unneeded checks in virt_to_scatterlist()
This is always called with a valid "sg" pointer.  My static checker
complains because the call to sg_init_table() dereferences "sg" before
we reach the checks.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
2013-01-28 16:38:37 -08:00
Tyler Hicks
111d61a25e eCryptfs: Fix -Wmissing-prototypes warnings
Mark two inode operation fuctions as static. Fixes warnings when
building with W=1.

Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
2013-01-17 12:20:47 -08:00
Tyler Hicks
bbcb03e3ce eCryptfs: Fix -Wunused-but-set-variable warnings
These two variables are no longer used and can be removed. Fixes
warnings when building with W=1.

Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
2013-01-17 11:36:10 -08:00
Simon Que
fa5199648e eCryptfs: initialize payload_len in keystore.c
This is meant to remove a compiler warning.  It should not make any
functional change.

payload_len should be initialized when it is passed to
write_tag_64_packet() as a pointer.  If that call fails, this function
should return early, and payload_len won't be used.

Signed-off-by: Simon Que <sque@chromium.org>
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
2013-01-17 11:31:25 -08:00
Kees Cook
336d6d0323 fs/ecryptfs: remove depends on CONFIG_EXPERIMENTAL
The CONFIG_EXPERIMENTAL config item has not carried much meaning for a
while now and is almost always enabled by default. As agreed during the
Linux kernel summit, remove it from any "depends on" lines in Kconfigs.

CC: Tyler Hicks <tyhicks@canonical.com>
CC: Dustin Kirkland <dustin.kirkland@gazzang.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Tyler Hicks <tyhicks@canonical.com>
2013-01-11 11:39:04 -08:00
Cong Ding
37028758f9 fs/ecryptfs/crypto.c: make ecryptfs_encode_for_filename() static
the function ecryptfs_encode_for_filename() is only used in this file

Signed-off-by: Cong Ding <dinggnu@gmail.com>
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
2012-12-18 10:10:13 -06:00
Wei Yongjun
8bbca57cff eCryptfs: fix to use list_for_each_entry_safe() when delete items
Since we will be removing items off the list using list_del() we need
to use a safer version of the list_for_each_entry() macro aptly named
list_for_each_entry_safe(). We should use the safe macro if the loop
involves deletions of items.

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
[tyhicks: Fixed compiler err - missing list_for_each_entry_safe() param]
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
2012-12-18 10:07:29 -06:00
Li Wang
e4bc6522d5 eCryptfs: Avoid unnecessary disk read and data decryption during writing
ecryptfs_write_begin grabs a page from page cache for writing.
If the page contains invalid data, or data older than the
counterpart on the disk, eCryptfs will read out the
corresponing data from the disk into the page, decrypt them,
then perform writing. However, for this page, if the length
of the data to be written into is equal to page size,
that means the whole page of data will be overwritten,
in which case, it does not matter whatever the data were before,
it is beneficial to perform writing directly rather than bothering
to read and decrypt first.

With this optimization, according to our test on a machine with
Intel Core 2 Duo processor, iozone 'write' operation on an existing
file with write size being multiple of page size will enjoy a steady
3x speedup.

Signed-off-by: Li Wang <wangli@kylinos.com.cn>
Signed-off-by: Yunchuan Wen <wenyunchuan@kylinos.com.cn>
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
2012-11-07 17:56:16 -08:00
Linus Torvalds
aab174f0df Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs update from Al Viro:

 - big one - consolidation of descriptor-related logics; almost all of
   that is moved to fs/file.c

   (BTW, I'm seriously tempted to rename the result to fd.c.  As it is,
   we have a situation when file_table.c is about handling of struct
   file and file.c is about handling of descriptor tables; the reasons
   are historical - file_table.c used to be about a static array of
   struct file we used to have way back).

   A lot of stray ends got cleaned up and converted to saner primitives,
   disgusting mess in android/binder.c is still disgusting, but at least
   doesn't poke so much in descriptor table guts anymore.  A bunch of
   relatively minor races got fixed in process, plus an ext4 struct file
   leak.

 - related thing - fget_light() partially unuglified; see fdget() in
   there (and yes, it generates the code as good as we used to have).

 - also related - bits of Cyrill's procfs stuff that got entangled into
   that work; _not_ all of it, just the initial move to fs/proc/fd.c and
   switch of fdinfo to seq_file.

 - Alex's fs/coredump.c spiltoff - the same story, had been easier to
   take that commit than mess with conflicts.  The rest is a separate
   pile, this was just a mechanical code movement.

 - a few misc patches all over the place.  Not all for this cycle,
   there'll be more (and quite a few currently sit in akpm's tree)."

Fix up trivial conflicts in the android binder driver, and some fairly
simple conflicts due to two different changes to the sock_alloc_file()
interface ("take descriptor handling from sock_alloc_file() to callers"
vs "net: Providing protocol type via system.sockprotoname xattr of
/proc/PID/fd entries" adding a dentry name to the socket)

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (72 commits)
  MAX_LFS_FILESIZE should be a loff_t
  compat: fs: Generic compat_sys_sendfile implementation
  fs: push rcu_barrier() from deactivate_locked_super() to filesystems
  btrfs: reada_extent doesn't need kref for refcount
  coredump: move core dump functionality into its own file
  coredump: prevent double-free on an error path in core dumper
  usb/gadget: fix misannotations
  fcntl: fix misannotations
  ceph: don't abuse d_delete() on failure exits
  hypfs: ->d_parent is never NULL or negative
  vfs: delete surplus inode NULL check
  switch simple cases of fget_light to fdget
  new helpers: fdget()/fdput()
  switch o2hb_region_dev_write() to fget_light()
  proc_map_files_readdir(): don't bother with grabbing files
  make get_file() return its argument
  vhost_set_vring(): turn pollstart/pollstop into bool
  switch prctl_set_mm_exe_file() to fget_light()
  switch xfs_find_handle() to fget_light()
  switch xfs_swapext() to fget_light()
  ...
2012-10-02 20:25:04 -07:00
Kirill A. Shutemov
8c0a853770 fs: push rcu_barrier() from deactivate_locked_super() to filesystems
There's no reason to call rcu_barrier() on every
deactivate_locked_super().  We only need to make sure that all delayed rcu
free inodes are flushed before we destroy related cache.

Removing rcu_barrier() from deactivate_locked_super() affects some fast
paths.  E.g.  on my machine exit_group() of a last process in IPC
namespace takes 0.07538s.  rcu_barrier() takes 0.05188s of that time.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-10-02 21:35:55 -04:00
Linus Torvalds
437589a74b Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull user namespace changes from Eric Biederman:
 "This is a mostly modest set of changes to enable basic user namespace
  support.  This allows the code to code to compile with user namespaces
  enabled and removes the assumption there is only the initial user
  namespace.  Everything is converted except for the most complex of the
  filesystems: autofs4, 9p, afs, ceph, cifs, coda, fuse, gfs2, ncpfs,
  nfs, ocfs2 and xfs as those patches need a bit more review.

  The strategy is to push kuid_t and kgid_t values are far down into
  subsystems and filesystems as reasonable.  Leaving the make_kuid and
  from_kuid operations to happen at the edge of userspace, as the values
  come off the disk, and as the values come in from the network.
  Letting compile type incompatible compile errors (present when user
  namespaces are enabled) guide me to find the issues.

  The most tricky areas have been the places where we had an implicit
  union of uid and gid values and were storing them in an unsigned int.
  Those places were converted into explicit unions.  I made certain to
  handle those places with simple trivial patches.

  Out of that work I discovered we have generic interfaces for storing
  quota by projid.  I had never heard of the project identifiers before.
  Adding full user namespace support for project identifiers accounts
  for most of the code size growth in my git tree.

  Ultimately there will be work to relax privlige checks from
  "capable(FOO)" to "ns_capable(user_ns, FOO)" where it is safe allowing
  root in a user names to do those things that today we only forbid to
  non-root users because it will confuse suid root applications.

  While I was pushing kuid_t and kgid_t changes deep into the audit code
  I made a few other cleanups.  I capitalized on the fact we process
  netlink messages in the context of the message sender.  I removed
  usage of NETLINK_CRED, and started directly using current->tty.

  Some of these patches have also made it into maintainer trees, with no
  problems from identical code from different trees showing up in
  linux-next.

  After reading through all of this code I feel like I might be able to
  win a game of kernel trivial pursuit."

Fix up some fairly trivial conflicts in netfilter uid/git logging code.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (107 commits)
  userns: Convert the ufs filesystem to use kuid/kgid where appropriate
  userns: Convert the udf filesystem to use kuid/kgid where appropriate
  userns: Convert ubifs to use kuid/kgid
  userns: Convert squashfs to use kuid/kgid where appropriate
  userns: Convert reiserfs to use kuid and kgid where appropriate
  userns: Convert jfs to use kuid/kgid where appropriate
  userns: Convert jffs2 to use kuid and kgid where appropriate
  userns: Convert hpfs to use kuid and kgid where appropriate
  userns: Convert btrfs to use kuid/kgid where appropriate
  userns: Convert bfs to use kuid/kgid where appropriate
  userns: Convert affs to use kuid/kgid wherwe appropriate
  userns: On alpha modify linux_to_osf_stat to use convert from kuids and kgids
  userns: On ia64 deal with current_uid and current_gid being kuid and kgid
  userns: On ppc convert current_uid from a kuid before printing.
  userns: Convert s390 getting uid and gid system calls to use kuid and kgid
  userns: Convert s390 hypfs to use kuid and kgid where appropriate
  userns: Convert binder ipc to use kuids
  userns: Teach security_path_chown to take kuids and kgids
  userns: Add user namespace support to IMA
  userns: Convert EVM to deal with kuids and kgids in it's hmac computation
  ...
2012-10-02 11:11:09 -07:00
Eric W. Biederman
cdf8c58a35 userns: Convert ecryptfs to use kuid/kgid where appropriate
Cc: Tyler Hicks <tyhicks@canonical.com>
Cc: Dustin Kirkland <dustin.kirkland@gazzang.com>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-09-21 03:13:09 -07:00
Tyler Hicks
8335eafc28 eCryptfs: Copy up attributes of the lower target inode after rename
After calling into the lower filesystem to do a rename, the lower target
inode's attributes were not copied up to the eCryptfs target inode. This
resulted in the eCryptfs target inode staying around, rather than being
evicted, because i_nlink was not updated for the eCryptfs inode. This
also meant that eCryptfs didn't do the final iput() on the lower target
inode so it stayed around, as well. This would result in a failure to
free up space occupied by the target file in the rename() operation.
Both target inodes would eventually be evicted when the eCryptfs
filesystem was unmounted.

This patch calls fsstack_copy_attr_all() after the lower filesystem
does its ->rename() so that important inode attributes, such as i_nlink,
are updated at the eCryptfs layer. ecryptfs_evict_inode() is now called
and eCryptfs can drop its final reference on the lower inode.

http://launchpad.net/bugs/561129

Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Tested-by: Colin Ian King <colin.king@canonical.com>
Cc: <stable@vger.kernel.org> [2.6.39+]
2012-09-14 09:36:03 -07:00
Tyler Hicks
64e6651dcc eCryptfs: Call lower ->flush() from ecryptfs_flush()
Since eCryptfs only calls fput() on the lower file in
ecryptfs_release(), eCryptfs should call the lower filesystem's
->flush() from ecryptfs_flush().

If the lower filesystem implements ->flush(), then eCryptfs should try
to flush out any dirty pages prior to calling the lower ->flush(). If
the lower filesystem does not implement ->flush(), then eCryptfs has no
need to do anything in ecryptfs_flush() since dirty pages are now
written out to the lower filesystem in ecryptfs_release().

Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
2012-09-14 09:35:54 -07:00
Tyler Hicks
7149f2558d eCryptfs: Write out all dirty pages just before releasing the lower file
Fixes a regression caused by:

821f749 eCryptfs: Revert to a writethrough cache model

That patch reverted some code (specifically, 32001d6f) that was
necessary to properly handle open() -> mmap() -> close() -> dirty pages
-> munmap(), because the lower file could be closed before the dirty
pages are written out.

Rather than reapplying 32001d6f, this approach is a better way of
ensuring that the lower file is still open in order to handle writing
out the dirty pages. It is called from ecryptfs_release(), while we have
a lock on the lower file pointer, just before the lower file gets the
final fput() and we overwrite the pointer.

https://launchpad.net/bugs/1047261

Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Reported-by: Artemy Tregubenko <me@arty.name>
Tested-by: Artemy Tregubenko <me@arty.name>
Tested-by: Colin Ian King <colin.king@canonical.com>
2012-09-14 09:11:29 -07:00
Linus Torvalds
410fc4ce8a - 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
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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
2012-08-02 10:56:34 -07:00
Al Viro
0b1d90119a ecryptfs_lookup_interpose(): allocate dentry_info first
less work on failure that way

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-29 21:24:17 +04:00
Al Viro
bc65a1215e sanitize ecryptfs_lookup()
* ->lookup() never gets hit with . or ..
* dentry it gets is unhashed, so unless we had gone and hashed it ourselves, there's
no need to d_drop() the sucker.
* wrong name printed in one of the printks (NULL, in fact)

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-29 21:24:16 +04:00
Al Viro
765927b2d5 switch dentry_open() to struct path, make it grab references itself
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-23 00:01:29 +04:00
Al Viro
3b8b487114 ecryptfs: don't reinvent the wheels, please - use struct completion
... and keep the sodding requests on stack - they are small enough.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-23 00:01:02 +04:00
Al Viro
8fc37ec54c don't expose I_NEW inodes via dentry->d_inode
d_instantiate(dentry, inode);
	unlock_new_inode(inode);

is a bad idea; do it the other way round...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-23 00:00:58 +04:00
David Howells
9249e17fe0 VFS: Pass mount flags to sget()
Pass mount flags to sget() so that it can use them in initialising a new
superblock before the set function is called.  They could also be passed to the
compare function.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-14 16:38:34 +04:00
Al Viro
312b63fba9 don't pass nameidata * to vfs_create()
all we want is a boolean flag, same as the method gets now

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-14 16:34:50 +04:00
Al Viro
ebfc3b49a7 don't pass nameidata to ->create()
boolean "does it have to be exclusive?" flag is passed instead;
Local filesystem should just ignore it - the object is guaranteed
not to be there yet.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-14 16:34:47 +04:00
Al Viro
00cd8dd3bf stop passing nameidata to ->lookup()
Just the flags; only NFS cares even about that, but there are
legitimate uses for such argument.  And getting rid of that
completely would require splitting ->lookup() into a couple
of methods (at least), so let's leave that alone for now...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-14 16:34:32 +04:00
Al Viro
0b728e1911 stop passing nameidata * to ->d_revalidate()
Just the lookup flags.  Die, bastard, die...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-14 16:34:14 +04:00
Tim Sally
5f5b331d5c eCryptfs: check for eCryptfs cipher support at mount
The issue occurs when eCryptfs is mounted with a cipher supported by
the crypto subsystem but not by eCryptfs. The mount succeeds and an
error does not occur until a write. This change checks for eCryptfs
cipher support at mount time.

Resolves Launchpad issue #338914, reported by Tyler Hicks in 03/2009.
https://bugs.launchpad.net/ecryptfs/+bug/338914

Signed-off-by: Tim Sally <tsally@atomicpeace.com>
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
2012-07-13 17:20:34 -07:00
Tyler Hicks
821f7494a7 eCryptfs: Revert to a writethrough cache model
A change was made about a year ago to get eCryptfs to better utilize its
page cache during writes. The idea was to do the page encryption
operations during page writeback, rather than doing them when initially
writing into the page cache, to reduce the number of page encryption
operations during sequential writes. This meant that the encrypted page
would only be written to the lower filesystem during page writeback,
which was a change from how eCryptfs had previously wrote to the lower
filesystem in ecryptfs_write_end().

The change caused a few eCryptfs-internal bugs that were shook out.
Unfortunately, more grave side effects have been identified that will
force changes outside of eCryptfs. Because the lower filesystem isn't
consulted until page writeback, eCryptfs has no way to pass lower write
errors (ENOSPC, mainly) back to userspace. Additionaly, it was reported
that quotas could be bypassed because of the way eCryptfs may sometimes
open the lower filesystem using a privileged kthread.

It would be nice to resolve the latest issues, but it is best if the
eCryptfs commits be reverted to the old behavior in the meantime.

This reverts:
32001d6f "eCryptfs: Flush file in vma close"
5be79de2 "eCryptfs: Flush dirty pages in setattr"
57db4e8d "ecryptfs: modify write path to encrypt page in writepage"

Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Tested-by: Colin King <colin.king@canonical.com>
Cc: Colin King <colin.king@canonical.com>
Cc: Thieu Le <thieule@google.com>
2012-07-13 16:46:06 -07:00
Tyler Hicks
e3ccaa9761 eCryptfs: Initialize empty lower files when opening them
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>
2012-07-08 12:51:45 -05:00
Tyler Hicks
8bc2d3cf61 eCryptfs: Unlink lower inode when ecryptfs_create() fails
ecryptfs_create() creates a lower inode, allocates an eCryptfs inode,
initializes the eCryptfs inode and cryptographic metadata attached to
the inode, and then writes the metadata to the header of the file.

If an error was to occur after the lower inode was created, an empty
lower file would be left in the lower filesystem. This is a problem
because ecryptfs_open() refuses to open any lower files which do not
have the appropriate metadata in the file header.

This patch properly unlinks the lower inode when an error occurs in the
later stages of ecryptfs_create(), reducing the chance that an empty
lower file will be left in the lower filesystem.

https://launchpad.net/bugs/872905

Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Cc: John Johansen <john.johansen@canonical.com>
Cc: Colin Ian King <colin.king@canonical.com>
2012-07-08 12:51:44 -05:00
Tyler Hicks
2ecaf55db6 eCryptfs: Make all miscdev functions use daemon ptr in file private_data
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>
2012-07-08 12:51:44 -05:00
Tyler Hicks
5669688665 eCryptfs: Remove unused messaging declarations and function
These are no longer needed.

Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Cc: Sasha Levin <levinsasha928@gmail.com>
2012-07-08 12:51:43 -05:00
Tyler Hicks
069ddcda37 eCryptfs: Copy up POSIX ACL and read-only flags from lower mount
When the eCryptfs mount options do not include '-o acl', but the lower
filesystem's mount options do include 'acl', the MS_POSIXACL flag is not
flipped on in the eCryptfs super block flags. This flag is what the VFS
checks in do_last() when deciding if the current umask should be applied
to a newly created inode's mode or not. When a default POSIX ACL mask is
set on a directory, the current umask is incorrectly applied to new
inodes created in the directory. This patch ignores the MS_POSIXACL flag
passed into ecryptfs_mount() and sets the flag on the eCryptfs super
block depending on the flag's presence on the lower super block.

Additionally, it is incorrect to allow a writeable eCryptfs mount on top
of a read-only lower mount. This missing check did not allow writes to
the read-only lower mount because permissions checks are still performed
on the lower filesystem's objects but it is best to simply not allow a
rw mount on top of ro mount. However, a ro eCryptfs mount on top of a rw
mount is valid and still allowed.

https://launchpad.net/bugs/1009207

Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Reported-by: Stefan Beller <stefanbeller@googlemail.com>
Cc: John Johansen <john.johansen@canonical.com>
2012-07-08 12:51:43 -05:00
Tyler Hicks
8dc6780587 eCryptfs: Gracefully refuse miscdev file ops on inherited/passed files
File operations on /dev/ecryptfs would BUG() when the operations were
performed by processes other than the process that originally opened the
file. This could happen with open files inherited after fork() or file
descriptors passed through IPC mechanisms. Rather than calling BUG(), an
error code can be safely returned in most situations.

In ecryptfs_miscdev_release(), eCryptfs still needs to handle the
release even if the last file reference is being held by a process that
didn't originally open the file. ecryptfs_find_daemon_by_euid() will not
be successful, so a pointer to the daemon is stored in the file's
private_data. The private_data pointer is initialized when the miscdev
file is opened and only used when the file is released.

https://launchpad.net/bugs/994247

Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Reported-by: Sasha Levin <levinsasha928@gmail.com>
Tested-by: Sasha Levin <levinsasha928@gmail.com>
2012-07-06 15:51:12 -05:00
Tyler Hicks
60d65f1f07 eCryptfs: Fix lockdep warning in miscdev operations
Don't grab the daemon mutex while holding the message context mutex.
Addresses this lockdep warning:

 ecryptfsd/2141 is trying to acquire lock:
  (&ecryptfs_msg_ctx_arr[i].mux){+.+.+.}, at: [<ffffffffa029c213>] ecryptfs_miscdev_read+0x143/0x470 [ecryptfs]

 but task is already holding lock:
  (&(*daemon)->mux){+.+...}, at: [<ffffffffa029c2ec>] ecryptfs_miscdev_read+0x21c/0x470 [ecryptfs]

 which lock already depends on the new lock.

 the existing dependency chain (in reverse order) is:

 -> #1 (&(*daemon)->mux){+.+...}:
        [<ffffffff810a3b8d>] lock_acquire+0x9d/0x220
        [<ffffffff8151c6da>] __mutex_lock_common+0x5a/0x4b0
        [<ffffffff8151cc64>] mutex_lock_nested+0x44/0x50
        [<ffffffffa029c5d7>] ecryptfs_send_miscdev+0x97/0x120 [ecryptfs]
        [<ffffffffa029b744>] ecryptfs_send_message+0x134/0x1e0 [ecryptfs]
        [<ffffffffa029a24e>] ecryptfs_generate_key_packet_set+0x2fe/0xa80 [ecryptfs]
        [<ffffffffa02960f8>] ecryptfs_write_metadata+0x108/0x250 [ecryptfs]
        [<ffffffffa0290f80>] ecryptfs_create+0x130/0x250 [ecryptfs]
        [<ffffffff811963a4>] vfs_create+0xb4/0x120
        [<ffffffff81197865>] do_last+0x8c5/0xa10
        [<ffffffff811998f9>] path_openat+0xd9/0x460
        [<ffffffff81199da2>] do_filp_open+0x42/0xa0
        [<ffffffff81187998>] do_sys_open+0xf8/0x1d0
        [<ffffffff81187a91>] sys_open+0x21/0x30
        [<ffffffff81527d69>] system_call_fastpath+0x16/0x1b

 -> #0 (&ecryptfs_msg_ctx_arr[i].mux){+.+.+.}:
        [<ffffffff810a3418>] __lock_acquire+0x1bf8/0x1c50
        [<ffffffff810a3b8d>] lock_acquire+0x9d/0x220
        [<ffffffff8151c6da>] __mutex_lock_common+0x5a/0x4b0
        [<ffffffff8151cc64>] mutex_lock_nested+0x44/0x50
        [<ffffffffa029c213>] ecryptfs_miscdev_read+0x143/0x470 [ecryptfs]
        [<ffffffff811887d3>] vfs_read+0xb3/0x180
        [<ffffffff811888ed>] sys_read+0x4d/0x90
        [<ffffffff81527d69>] system_call_fastpath+0x16/0x1b

Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
2012-07-03 16:34:10 -07:00
Tyler Hicks
9fe79d7600 eCryptfs: Properly check for O_RDONLY flag before doing privileged open
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 <tyhicks@canonical.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Dan Carpenter <dan.carpenter@oracle.com>
2012-07-03 16:34:09 -07:00
Al Viro
408bd629ba get rid of pointless allocations and copying in ecryptfs_follow_link()
switch to generic_readlink(), while we are at it

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-05-29 23:28:40 -04:00
Linus Torvalds
90324cc1b1 avoid iput() from flusher thread
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Merge tag 'writeback' of git://git.kernel.org/pub/scm/linux/kernel/git/wfg/linux

Pull writeback tree from Wu Fengguang:
 "Mainly from Jan Kara to avoid iput() in the flusher threads."

* tag 'writeback' of git://git.kernel.org/pub/scm/linux/kernel/git/wfg/linux:
  writeback: Avoid iput() from flusher thread
  vfs: Rename end_writeback() to clear_inode()
  vfs: Move waiting for inode writeback from end_writeback() to evict_inode()
  writeback: Refactor writeback_single_inode()
  writeback: Remove wb->list_lock from writeback_single_inode()
  writeback: Separate inode requeueing after writeback
  writeback: Move I_DIRTY_PAGES handling
  writeback: Move requeueing when I_SYNC set to writeback_sb_inodes()
  writeback: Move clearing of I_SYNC into inode_sync_complete()
  writeback: initialize global_dirty_limit
  fs: remove 8 bytes of padding from struct writeback_control on 64 bit builds
  mm: page-writeback.c: local functions should not be exposed globally
2012-05-28 09:54:45 -07:00
Jan Kara
dbd5768f87 vfs: Rename end_writeback() to clear_inode()
After we moved inode_sync_wait() from end_writeback() it doesn't make sense
to call the function end_writeback() anymore. Rename it to clear_inode()
which well says what the function really does - set I_CLEAR flag.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
2012-05-06 13:43:41 +08:00
Eric W. Biederman
c4a4d60379 userns: Use cred->user_ns instead of cred->user->user_ns
Optimize performance and prepare for the removal of the user_ns reference
from user_struct.  Remove the slow long walk through cred->user->user_ns and
instead go straight to cred->user_ns.

Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-04-07 16:55:51 -07:00
Al Viro
0794f569ec ecryptfs: make register_filesystem() the last potential failure exit
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-03-20 21:29:49 -04:00
Al Viro
68ac1234fb switch touch_atime to struct path
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-03-20 21:29:41 -04:00
Al Viro
48fde701af switch open-coded instances of d_make_root() to new helper
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-03-20 21:29:35 -04:00
Al Viro
e28e832c3e ecryptfs: don't bother with ->drop_inode()
generic_drop_inode() is the default

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-03-20 21:29:33 -04:00
Randy Dunlap
164974a8f2 ecryptfs: fix printk format warning for size_t
Fix printk format warning (from Linus's suggestion):

on i386:
  fs/ecryptfs/miscdev.c:433:38: warning: format '%lu' expects type 'long unsigned int', but argument 4 has type 'unsigned int'

and on x86_64:
  fs/ecryptfs/miscdev.c:433:38: warning: format '%u' expects type 'unsigned int', but argument 4 has type 'long unsigned int'

Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Cc:	Geert Uytterhoeven <geert@linux-m68k.org>
Cc:	Tyler Hicks <tyhicks@canonical.com>
Cc:	Dustin Kirkland <dustin.kirkland@gazzang.com>
Cc:	ecryptfs@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-02-28 16:55:30 -08:00
Cong Wang
465c9343c5 ecryptfs: remove the second argument of k[un]map_atomic()
Signed-off-by: Cong Wang <amwang@redhat.com>
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
2012-02-16 16:06:27 -06:00
Tyler Hicks
545d680938 eCryptfs: Copy up lower inode attrs after setting lower xattr
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 <tyhicks@canonical.com>
Reported-by: Sebastien Bacher <seb128@ubuntu.com>
Cc: John Johansen <john.johansen@canonical.com>
Cc: <stable@vger.kernel.org>
2012-02-16 16:06:27 -06:00
Tyler Hicks
4a26620df4 eCryptfs: Improve statfs reporting
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>
2012-02-16 16:06:21 -06:00
Li Wang
1589cb1a94 eCryptfs: move misleading function comments
The data encryption was moved from ecryptfs_write_end into
ecryptfs_writepage, this patch moves the corresponding function
comments to be consistent with the modification.

Signed-off-by: Li Wang <liwang@nudt.edu.cn>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-25 15:10:53 -08:00
Tyler Hicks
58ded24f0f eCryptfs: Fix oops when printing debug info in extent crypto functions
If pages passed to the eCryptfs extent-based crypto functions are not
mapped and the module parameter ecryptfs_verbosity=1 was specified at
loading time, a NULL pointer dereference will occur.

Note that this wouldn't happen on a production system, as you wouldn't
pass ecryptfs_verbosity=1 on a production system. It leaks private
information to the system logs and is for debugging only.

The debugging info printed in these messages is no longer very useful
and rather than doing a kmap() in these debugging paths, it will be
better to simply remove the debugging paths completely.

https://launchpad.net/bugs/913651

Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Reported-by: Daniel DeFreez
Cc: <stable@vger.kernel.org>
2012-01-25 14:43:42 -06:00
Tyler Hicks
f2cb933501 eCryptfs: Remove unused ecryptfs_read()
ecryptfs_read() has been ifdef'ed out for years now and it was
apparently unused before then. It is time to get rid of it for good.

Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
2012-01-25 14:43:41 -06:00
Tyler Hicks
a261a03904 eCryptfs: Check inode changes in setattr
Most filesystems call inode_change_ok() very early in ->setattr(), but
eCryptfs didn't call it at all. It allowed the lower filesystem to make
the call in its ->setattr() function. Then, eCryptfs would copy the
appropriate inode attributes from the lower inode to the eCryptfs inode.

This patch changes that and actually calls inode_change_ok() on the
eCryptfs inode, fairly early in ecryptfs_setattr(). Ideally, the call
would happen earlier in ecryptfs_setattr(), but there are some possible
inode initialization steps that must happen first.

Since the call was already being made on the lower inode, the change in
functionality should be minimal, except for the case of a file extending
truncate call. In that case, inode_newsize_ok() was never being
called on the eCryptfs inode. Rather than inode_newsize_ok() catching
maximum file size errors early on, eCryptfs would encrypt zeroed pages
and write them to the lower filesystem until the lower filesystem's
write path caught the error in generic_write_checks(). This patch
introduces a new function, called ecryptfs_inode_newsize_ok(), which
checks if the new lower file size is within the appropriate limits when
the truncate operation will be growing the lower file.

In summary this change prevents eCryptfs truncate operations (and the
resulting page encryptions), which would exceed the lower filesystem
limits or FSIZE rlimits, from ever starting.

Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Reviewed-by: Li Wang <liwang@nudt.edu.cn>
Cc: <stable@vger.kernel.org>
2012-01-25 14:43:41 -06:00
Tyler Hicks
5e6f0d7690 eCryptfs: Make truncate path killable
ecryptfs_write() handles the truncation of eCryptfs inodes. It grabs a
page, zeroes out the appropriate portions, and then encrypts the page
before writing it to the lower filesystem. It was unkillable and due to
the lack of sparse file support could result in tying up a large portion
of system resources, while encrypting pages of zeros, with no way for
the truncate operation to be stopped from userspace.

This patch adds the ability for ecryptfs_write() to detect a pending
fatal signal and return as gracefully as possible. The intent is to
leave the lower file in a useable state, while still allowing a user to
break out of the encryption loop. If a pending fatal signal is detected,
the eCryptfs inode size is updated to reflect the modified inode size
and then -EINTR is returned.

Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Cc: <stable@vger.kernel.org>
2012-01-25 14:43:40 -06:00
Li Wang
684a3ff7e6 eCryptfs: Infinite loop due to overflow in ecryptfs_write()
ecryptfs_write() can enter an infinite loop when truncating a file to a
size larger than 4G. This only happens on architectures where size_t is
represented by 32 bits.

This was caused by a size_t overflow due to it incorrectly being used to
store the result of a calculation which uses potentially large values of
type loff_t.

[tyhicks@canonical.com: rewrite subject and commit message]
Signed-off-by: Li Wang <liwang@nudt.edu.cn>
Signed-off-by: Yunchuan Wen <wenyunchuan@kylinos.com.cn>
Reviewed-by: Cong Wang <xiyou.wangcong@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
2012-01-25 14:43:40 -06:00
Tyler Hicks
48399c0b0e eCryptfs: Replace miscdev read/write magic numbers
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>
2012-01-25 14:43:40 -06:00
Tyler Hicks
7f13350424 eCryptfs: Report errors in writes to /dev/ecryptfs
Errors in writes to /dev/ecryptfs were being incorrectly reported by
returning 0 or the value of the original write count.

This patch clears up the return code assignment in error paths.

Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
2012-01-25 14:43:39 -06:00
Tyler Hicks
db10e55651 eCryptfs: Sanitize write counts of /dev/ecryptfs
A malicious count value specified when writing to /dev/ecryptfs may
result in a a very large kernel memory allocation.

This patch peeks at the specified packet payload size, adds that to the
size of the packet headers and compares the result with the write count
value. The resulting maximum memory allocation size is approximately 532
bytes.

Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Reported-by: Sasha Levin <levinsasha928@gmail.com>
Cc: <stable@vger.kernel.org>
2012-01-25 14:43:39 -06:00
Tim Gardner
bb4503615d ecryptfs: Remove unnecessary variable initialization
Removes unneeded variable initialization in ecryptfs_read_metadata(). Also adds
a small comment to help explain metadata reading logic.

[tyhicks@canonical.com: Pulled out of for-stable patch and wrote commit msg]
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
2012-01-25 14:43:38 -06:00
Tim Gardner
30373dc0c8 ecryptfs: Improve metadata read failure logging
Print inode on metadata read failure. The only real
way of dealing with metadata read failures is to delete
the underlying file system file. Having the inode
allows one to 'find . -inum INODE`.

[tyhicks@canonical.com: Removed some minor not-for-stable parts]
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: stable@vger.kernel.org
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
2012-01-25 14:43:38 -06:00
Al Viro
34c80b1d93 vfs: switch ->show_options() to struct dentry *
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-01-06 23:19:54 -05:00
Al Viro
175a4eb7ea fs: propagate umode_t, misc bits
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-01-03 22:55:10 -05:00
Al Viro
18cb1b08d2 kill ecryptfs_create_underlying_file()
it's a just a wrapper for vfs_create()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-01-03 22:54:57 -05:00
Al Viro
1a67aafb5f switch ->mknod() to umode_t
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-01-03 22:54:54 -05:00
Al Viro
4acdaf27eb switch ->create() to umode_t
vfs_create() ignores everything outside of 16bit subset of its
mode argument; switching it to umode_t is obviously equivalent
and it's the only caller of the method

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-01-03 22:54:53 -05:00
Al Viro
18bb1db3e7 switch vfs_mkdir() and ->mkdir() to umode_t
vfs_mkdir() gets int, but immediately drops everything that might not
fit into umode_t and that's the only caller of ->mkdir()...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-01-03 22:54:53 -05:00
Al Viro
6b520e0565 vfs: fix the stupidity with i_dentry in inode destructors
Seeing that just about every destructor got that INIT_LIST_HEAD() copied into
it, there is no point whatsoever keeping this INIT_LIST_HEAD in inode_init_once();
the cost of taking it into inode_init_always() will be negligible for pipes
and sockets and negative for everything else.  Not to mention the removal of
boilerplate code from ->destroy_inode() instances...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-01-03 22:52:40 -05:00
Tyler Hicks
0f751e641a eCryptfs: Extend array bounds for all filename chars
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 <tyhicks@canonical.com>
Reported-by: Michael Halcrow <mhalcrow@google.com>
Cc: stable@kernel.org
2011-11-23 15:43:53 -06:00
Tyler Hicks
32001d6fe9 eCryptfs: Flush file in vma close
Dirty pages weren't being written back when an mmap'ed eCryptfs file was
closed before the mapping was unmapped. Since f_ops->flush() is not
called by the munmap() path, the lower file was simply being released.
This patch flushes the eCryptfs file in the vm_ops->close() path.

https://launchpad.net/bugs/870326

Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Cc: stable@kernel.org [2.6.39+]
2011-11-23 15:40:09 -06:00
Tyler Hicks
b59db43ad4 eCryptfs: Prevent file create race condition
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
2011-11-23 15:39:38 -06:00
Miklos Szeredi
bfe8684869 filesystems: add set_nlink()
Replace remaining direct i_nlink updates with a new set_nlink()
updater function.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Tested-by: Toshiyuki Okajima <toshi.okajima@jp.fujitsu.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2011-11-02 12:53:43 +01:00
Joe Perches
b9075fa968 treewide: use __printf not __attribute__((format(printf,...)))
Standardize the style for compiler based printf format verification.
Standardized the location of __printf too.

Done via script and a little typing.

$ grep -rPl --include=*.[ch] -w "__attribute__" * | \
  grep -vP "^(tools|scripts|include/linux/compiler-gcc.h)" | \
  xargs perl -n -i -e 'local $/; while (<>) { s/\b__attribute__\s*\(\s*\(\s*format\s*\(\s*printf\s*,\s*(.+)\s*,\s*(.+)\s*\)\s*\)\s*\)/__printf($1, $2)/g ; print; }'

[akpm@linux-foundation.org: revert arch bits]
Signed-off-by: Joe Perches <joe@perches.com>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-10-31 17:30:54 -07:00
John Johansen
764355487e Ecryptfs: Add mount option to check uid of device being mounted = expect uid
Close a TOCTOU race for mounts done via ecryptfs-mount-private.  The mount
source (device) can be raced when the ownership test is done in userspace.
Provide Ecryptfs a means to force the uid check at mount time.

Signed-off-by: John Johansen <john.johansen@canonical.com>
Cc: <stable@kernel.org>
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
2011-08-09 23:29:01 -05:00
Tyler Hicks
99b373ff2d eCryptfs: Fix payload_len unitialized variable warning
fs/ecryptfs/keystore.c: In function ‘ecryptfs_generate_key_packet_set’:
fs/ecryptfs/keystore.c:1991:28: warning: ‘payload_len’ may be used uninitialized in this function [-Wuninitialized]
fs/ecryptfs/keystore.c:1976:9: note: ‘payload_len’ was declared here

Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
2011-08-09 13:42:46 -05:00
Roberto Sassu
4b6fee17b1 eCryptfs: fix compile error
This patch fixes the compile error reported at the address:

https://bugzilla.kernel.org/show_bug.cgi?id=40292

The problem arises when compiling eCryptfs as built-in and the 'encrypted'
key type as a module. The patch prevents this combination from being set in
the kernel configuration, by fixing the eCryptfs dependencies.

Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Reported-by: David Hill <hilld@binarystorm.net>
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
2011-08-09 13:42:46 -05:00
Tyler Hicks
f61500e000 eCryptfs: Return error when lower file pointer is NULL
When an eCryptfs inode's lower file has been closed, and the pointer has
been set to NULL, return an error when trying to do a lower read or
write rather than calling BUG().

https://bugzilla.kernel.org/show_bug.cgi?id=37292

Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
Cc: <stable@kernel.org>
2011-08-09 13:42:45 -05:00
Thieu Le
985ca0e626 ecryptfs: Make inode bdi consistent with superblock bdi
Make the inode mapping bdi consistent with the superblock bdi so that
dirty pages are flushed properly.

Signed-off-by: Thieu Le <thieule@chromium.org>
Cc: <stable@kernel.org> [2.6.39+]
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
2011-07-28 23:48:26 -05:00
Tyler Hicks
b2987a5e05 eCryptfs: Unlock keys needed by ecryptfsd
Fixes a regression caused by b5695d0463

Kernel keyring keys containing eCryptfs authentication tokens should not
be write locked when calling out to ecryptfsd to wrap and unwrap file
encryption keys. The eCryptfs kernel code can not hold the key's write
lock because ecryptfsd needs to request the key after receiving such a
request from the kernel.

Without this fix, all file opens and creates will timeout and fail when
using the eCryptfs PKI infrastructure. This is not an issue when using
passphrase-based mount keys, which is the most widely deployed eCryptfs
configuration.

Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
Acked-by: Roberto Sassu <roberto.sassu@polito.it>
Tested-by: Roberto Sassu <roberto.sassu@polito.it>
Tested-by: Alexis Hafner1 <haf@zurich.ibm.com>
Cc: <stable@kernel.org> [2.6.39+]
2011-07-28 23:30:09 -05:00
Linus Torvalds
95b6886526 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6: (54 commits)
  tpm_nsc: Fix bug when loading multiple TPM drivers
  tpm: Move tpm_tis_reenable_interrupts out of CONFIG_PNP block
  tpm: Fix compilation warning when CONFIG_PNP is not defined
  TOMOYO: Update kernel-doc.
  tpm: Fix a typo
  tpm_tis: Probing function for Intel iTPM bug
  tpm_tis: Fix the probing for interrupts
  tpm_tis: Delay ACPI S3 suspend while the TPM is busy
  tpm_tis: Re-enable interrupts upon (S3) resume
  tpm: Fix display of data in pubek sysfs entry
  tpm_tis: Add timeouts sysfs entry
  tpm: Adjust interface timeouts if they are too small
  tpm: Use interface timeouts returned from the TPM
  tpm_tis: Introduce durations sysfs entry
  tpm: Adjust the durations if they are too small
  tpm: Use durations returned from TPM
  TOMOYO: Enable conditional ACL.
  TOMOYO: Allow using argv[]/envp[] of execve() as conditions.
  TOMOYO: Allow using executable's realpath and symlink's target as conditions.
  TOMOYO: Allow using owner/group etc. of file objects as conditions.
  ...

Fix up trivial conflict in security/tomoyo/realpath.c
2011-07-27 19:26:38 -07:00
Linus Torvalds
d3ec4844d4 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (43 commits)
  fs: Merge split strings
  treewide: fix potentially dangerous trailing ';' in #defined values/expressions
  uwb: Fix misspelling of neighbourhood in comment
  net, netfilter: Remove redundant goto in ebt_ulog_packet
  trivial: don't touch files that are removed in the staging tree
  lib/vsprintf: replace link to Draft by final RFC number
  doc: Kconfig: `to be' -> `be'
  doc: Kconfig: Typo: square -> squared
  doc: Konfig: Documentation/power/{pm => apm-acpi}.txt
  drivers/net: static should be at beginning of declaration
  drivers/media: static should be at beginning of declaration
  drivers/i2c: static should be at beginning of declaration
  XTENSA: static should be at beginning of declaration
  SH: static should be at beginning of declaration
  MIPS: static should be at beginning of declaration
  ARM: static should be at beginning of declaration
  rcu: treewide: Do not use rcu_read_lock_held when calling rcu_dereference_check
  Update my e-mail address
  PCIe ASPM: forcedly -> forcibly
  gma500: push through device driver tree
  ...

Fix up trivial conflicts:
 - arch/arm/mach-ep93xx/dma-m2p.c (deleted)
 - drivers/gpio/gpio-ep93xx.c (renamed and context nearby)
 - drivers/net/r8169.c (just context changes)
2011-07-25 13:56:39 -07:00
Jean Delvare
df2e301fee fs: Merge split strings
No idea why these were split in the first place...

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2011-07-22 16:47:15 +02:00
Josef Bacik
02c24a8218 fs: push i_mutex and filemap_write_and_wait down into ->fsync() handlers
Btrfs needs to be able to control how filemap_write_and_wait_range() is called
in fsync to make it less of a painful operation, so push down taking i_mutex and
the calling of filemap_write_and_wait() down into the ->fsync() handlers.  Some
file systems can drop taking the i_mutex altogether it seems, like ext3 and
ocfs2.  For correctness sake I just pushed everything down in all cases to make
sure that we keep the current behavior the same for everybody, and then each
individual fs maintainer can make up their mind about what to do from there.
Thanks,

Acked-by: Jan Kara <jack@suse.cz>
Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20 20:47:59 -04:00
Al Viro
bf6c7f6c7b don't pass nameidata to vfs_create() from ecryptfs_create()
Instead of playing with removal of LOOKUP_OPEN, mangling (and
restoring) nd->path, just pass NULL to vfs_create().  The whole
point of what's being done there is to suppress any attempts
to open file by underlying fs, which is what nd == NULL indicates.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20 01:43:54 -04:00
Al Viro
beefebf1aa ecryptfs_inode_permission() doesn't need to bail out on RCU
... now that inode_permission() can take MAY_NOT_BLOCK and handle it
properly.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20 01:43:38 -04:00
Al Viro
10556cb21a ->permission() sanitizing: don't pass flags to ->permission()
not used by the instances anymore.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20 01:43:24 -04:00
Roberto Sassu
1252cc3b23 eCryptfs: added support for the encrypted key type
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>
2011-06-27 09:11:21 -04:00
Roberto Sassu
f8f8527103 eCryptfs: export global eCryptfs definitions to include/linux/ecryptfs.h
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>
2011-06-27 09:11:02 -04:00
Tyler Hicks
3063287053 eCryptfs: Remove ecryptfs_header_cache_2
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>
2011-05-29 14:24:25 -05:00
Tyler Hicks
778aeb42a7 eCryptfs: Cleanup and optimize ecryptfs_lookup_interpose()
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>
2011-05-29 14:24:24 -05:00
Tyler Hicks
7a86617e55 eCryptfs: Return useful code from contains_ecryptfs_marker
Instead of having the calling functions translate the true/false return
code to either 0 or -EINVAL, have contains_ecryptfs_marker() return 0 or
-EINVAL so that the calling functions can just reuse the return code.

Also, rename the function to ecryptfs_validate_marker() to avoid callers
mistakenly thinking that it returns true/false codes.

Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
2011-05-29 14:24:24 -05:00
Tyler Hicks
3b06b3ebf4 eCryptfs: Fix new inode race condition
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>
2011-05-29 14:23:39 -05:00