Commit Graph

77 Commits

Author SHA1 Message Date
Linus Torvalds
5133cd7518 Merge branch 'fsnotify' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs
Pull fsnotify updates from Jan Kara:
 "The branch contains mainly a rework of fsnotify infrastructure fixing
  a shortcoming that we have waited for response to fanotify permission
  events with SRCU read lock held and when the process consuming events
  was slow to respond the kernel has stalled.

  It also contains several cleanups of unnecessary indirections in
  fsnotify framework and a bugfix from Amir fixing leakage of kernel
  internal errno to userspace"

* 'fsnotify' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs: (37 commits)
  fanotify: don't expose EOPENSTALE to userspace
  fsnotify: remove a stray unlock
  fsnotify: Move ->free_mark callback to fsnotify_ops
  fsnotify: Add group pointer in fsnotify_init_mark()
  fsnotify: Drop inode_mark.c
  fsnotify: Remove fsnotify_find_{inode|vfsmount}_mark()
  fsnotify: Remove fsnotify_detach_group_marks()
  fsnotify: Rename fsnotify_clear_marks_by_group_flags()
  fsnotify: Inline fsnotify_clear_{inode|vfsmount}_mark_group()
  fsnotify: Remove fsnotify_recalc_{inode|vfsmount}_mask()
  fsnotify: Remove fsnotify_set_mark_{,ignored_}mask_locked()
  fanotify: Release SRCU lock when waiting for userspace response
  fsnotify: Pass fsnotify_iter_info into handle_event handler
  fsnotify: Provide framework for dropping SRCU lock in ->handle_event
  fsnotify: Remove special handling of mark destruction on group shutdown
  fsnotify: Detach mark from object list when last reference is dropped
  fsnotify: Move queueing of mark for destruction into fsnotify_put_mark()
  inotify: Do not drop mark reference under idr_lock
  fsnotify: Free fsnotify_mark_connector when there is no mark attached
  fsnotify: Lock object list with connector lock
  ...
2017-05-03 11:05:15 -07:00
Elena Reshetova
9d2378f8c8 audit: convert audit_tree.count from atomic_t to refcount_t
refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.

Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David Windsor <dwindsor@gmail.com>
[PM: fix subject line, add #include]
Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-05-02 10:16:04 -04:00
Jan Kara
054c636e5c fsnotify: Move ->free_mark callback to fsnotify_ops
Pointer to ->free_mark callback unnecessarily occupies one long in each
fsnotify_mark although they are the same for all marks from one
notification group. Move the callback pointer to fsnotify_ops.

Reviewed-by: Miklos Szeredi <mszeredi@redhat.com>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2017-04-10 17:37:36 +02:00
Jan Kara
7b12932340 fsnotify: Add group pointer in fsnotify_init_mark()
Currently we initialize mark->group only in fsnotify_add_mark_lock().
However we will need to access fsnotify_ops of corresponding group from
fsnotify_put_mark() so we need mark->group initialized earlier. Do that
in fsnotify_init_mark() which has a consequence that once
fsnotify_init_mark() is called on a mark, the mark has to be destroyed
by fsnotify_put_mark().

Reviewed-by: Miklos Szeredi <mszeredi@redhat.com>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2017-04-10 17:37:36 +02:00
Jan Kara
b1362edfe1 fsnotify: Remove fsnotify_find_{inode|vfsmount}_mark()
These are very thin wrappers, just remove them. Drop
fs/notify/vfsmount_mark.c as it is empty now.

Reviewed-by: Miklos Szeredi <mszeredi@redhat.com>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2017-04-10 17:37:36 +02:00
Jan Kara
9385a84d7e fsnotify: Pass fsnotify_iter_info into handle_event handler
Pass fsnotify_iter_info into ->handle_event() handler so that it can
release and reacquire SRCU lock via fsnotify_prepare_user_wait() and
fsnotify_finish_user_wait() functions.  These functions also make sure
current marks are appropriately pinned so that iteration protected by
srcu in fsnotify() stays safe.

Reviewed-by: Miklos Szeredi <mszeredi@redhat.com>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2017-04-10 17:37:36 +02:00
Jan Kara
6b3f05d24d fsnotify: Detach mark from object list when last reference is dropped
Instead of removing mark from object list from fsnotify_detach_mark(),
remove the mark when last reference to the mark is dropped. This will
allow fanotify to wait for userspace response to event without having to
hold onto fsnotify_mark_srcu.

To avoid pinning inodes by elevated refcount (and thus e.g. delaying
file deletion) while someone holds mark reference, we detach connector
from the object also from fsnotify_destroy_marks() and not only after
removing last mark from the list as it was now.

Reviewed-by: Miklos Szeredi <mszeredi@redhat.com>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2017-04-10 17:37:36 +02:00
Jan Kara
86ffe245c4 fsnotify: Move object pointer to fsnotify_mark_connector
Move pointer to inode / vfsmount from mark itself to the
fsnotify_mark_connector structure. This is another step on the path
towards decoupling inode / vfsmount lifetime from notification mark
lifetime.

Reviewed-by: Miklos Szeredi <mszeredi@redhat.com>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2017-04-10 17:37:35 +02:00
Jan Kara
43471d15df audit_tree: Use mark flags to check whether mark is alive
Currently audit code uses checking of mark->inode to verify whether mark
is still alive. Switch that to checking mark flags as that is more
logical and current way will become unreliable in future.

Reviewed-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2017-04-10 17:36:32 +02:00
Jan Kara
f410ff6554 audit: Abstract hash key handling
Audit tree currently uses inode pointer as a key into the hash table.
Getting that from notification mark will be somewhat more difficult with
coming fsnotify changes. So abstract getting of hash key from the audit
chunk and inode so that we can change the method to obtain a key easily.

Reviewed-by: Miklos Szeredi <mszeredi@redhat.com>
CC: Paul Moore <paul@paul-moore.com>
Acked-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2017-04-05 09:39:37 +02:00
Linus Torvalds
6989606a72 Merge branch 'stable-4.10' of git://git.infradead.org/users/pcmoore/audit
Pull audit fixes from Paul Moore:
 "Two small fixes relating to audit's use of fsnotify.

  The first patch plugs a leak and the second fixes some lock
  shenanigans. The patches are small and I banged on this for an
  afternoon with our testsuite and didn't see anything odd"

* 'stable-4.10' of git://git.infradead.org/users/pcmoore/audit:
  audit: Fix sleep in atomic
  fsnotify: Remove fsnotify_duplicate_mark()
2017-01-05 23:06:06 -08:00
Jan Kara
be29d20f3f audit: Fix sleep in atomic
Audit tree code was happily adding new notification marks while holding
spinlocks. Since fsnotify_add_mark() acquires group->mark_mutex this can
lead to sleeping while holding a spinlock, deadlocks due to lock
inversion, and probably other fun. Fix the problem by acquiring
group->mark_mutex earlier.

CC: Paul Moore <paul@paul-moore.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-01-03 15:56:38 -05:00
Jan Kara
e3ba730702 fsnotify: Remove fsnotify_duplicate_mark()
There are only two calls sites of fsnotify_duplicate_mark(). Those are
in kernel/audit_tree.c and both are bogus. Vfsmount pointer is unused
for audit tree, inode pointer and group gets set in
fsnotify_add_mark_locked() later anyway, mask and free_mark are already
set in alloc_chunk(). In fact, calling fsnotify_duplicate_mark() is
actively harmful because following fsnotify_add_mark_locked() will leak
group reference by overwriting the group pointer. So just remove the two
calls to fsnotify_duplicate_mark() and the function.

Signed-off-by: Jan Kara <jack@suse.cz>
[PM: line wrapping to fit in 80 chars]
Signed-off-by: Paul Moore <paul@paul-moore.com>
2016-12-23 16:40:32 -05:00
Linus Torvalds
0110c350c8 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull more vfs updates from Al Viro:
 "In this pile:

   - autofs-namespace series
   - dedupe stuff
   - more struct path constification"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (40 commits)
  ocfs2: implement the VFS clone_range, copy_range, and dedupe_range features
  ocfs2: charge quota for reflinked blocks
  ocfs2: fix bad pointer cast
  ocfs2: always unlock when completing dio writes
  ocfs2: don't eat io errors during _dio_end_io_write
  ocfs2: budget for extent tree splits when adding refcount flag
  ocfs2: prohibit refcounted swapfiles
  ocfs2: add newlines to some error messages
  ocfs2: convert inode refcount test to a helper
  simple_write_end(): don't zero in short copy into uptodate
  exofs: don't mess with simple_write_{begin,end}
  9p: saner ->write_end() on failing copy into non-uptodate page
  fix gfs2_stuffed_write_end() on short copies
  fix ceph_write_end()
  nfs_write_end(): fix handling of short copies
  vfs: refactor clone/dedupe_file_range common functions
  fs: try to clone files first in vfs_copy_file_range
  vfs: misc struct path constification
  namespace.c: constify struct path passed to a bunch of primitives
  quota: constify struct path in quota_on
  ...
2016-12-17 18:44:00 -08:00
Al Viro
3cd5eca8d7 fsnotify: constify 'data' passed to ->handle_event()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-12-05 18:58:31 -05:00
Steve Grubb
c1e8f06d7a audit: fix formatting of AUDIT_CONFIG_CHANGE events
The AUDIT_CONFIG_CHANGE events sometimes use a op= field. The current
code logs the value of the field with quotes. This field is documented
to not be encoded, so it should not have quotes.

Signed-off-by: Steve Grubb <sgrubb@redhat.com>
Reviewed-by: Richard Guy Briggs <rgb@redhat.com>
[PM: reformatted commit description to make checkpatch.pl happy]
Signed-off-by: Paul Moore <paul@paul-moore.com>
2016-11-20 15:38:00 -05:00
Jiri Slaby
0bf676d1fd audit: cleanup prune_tree_thread
We can use kthread_run instead of kthread_create+wake_up_process for
creating the thread.

We do not need to set the task state to TASK_RUNNING after schedule(),
the process is in that state already.

And we do not need to set the state to TASK_INTERRUPTIBLE when not
doing schedule() as we set the state to TASK_RUNNING immediately
afterwards.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Eric Paris <eparis@redhat.com>
Cc: <linux-audit@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2016-04-04 09:46:47 -04:00
Yaowei Bai
6f1b5d7afe audit: audit_tree_match can be boolean
This patch makes audit_tree_match return bool to improve readability
due to this particular function only using either one or zero as its
return value.

No functional change.

Signed-off-by: Yaowei Bai <bywxiaobai@163.com>
[PM: tweaked the subject line]
Signed-off-by: Paul Moore <pmoore@redhat.com>
2015-11-04 08:23:51 -05:00
Linus Torvalds
425afcff13 Merge branch 'upstream' of git://git.infradead.org/users/pcmoore/audit
Pull audit update from Paul Moore:
 "This is one of the larger audit patchsets in recent history,
  consisting of eight patches and almost 400 lines of changes.

  The bulk of the patchset is the new "audit by executable"
  functionality which allows admins to set an audit watch based on the
  executable on disk.  Prior to this, admins could only track an
  application by PID, which has some obvious limitations.

  Beyond the new functionality we also have some refcnt fixes and a few
  minor cleanups"

* 'upstream' of git://git.infradead.org/users/pcmoore/audit:
  fixup: audit: implement audit by executable
  audit: implement audit by executable
  audit: clean simple fsnotify implementation
  audit: use macros for unset inode and device values
  audit: make audit_del_rule() more robust
  audit: fix uninitialized variable in audit_add_rule()
  audit: eliminate unnecessary extra layer of watch parent references
  audit: eliminate unnecessary extra layer of watch references
2015-09-08 13:34:59 -07:00
Richard Guy Briggs
34d99af52a audit: implement audit by executable
This adds the ability audit the actions of a not-yet-running process.

This patch implements the ability to filter on the executable path.  Instead of
just hard coding the ino and dev of the executable we care about at the moment
the rule is inserted into the kernel, use the new audit_fsnotify
infrastructure to manage this dynamically.  This means that if the filename
does not yet exist but the containing directory does, or if the inode in
question is unlinked and creat'd (aka updated) the rule will just continue to
work.  If the containing directory is moved or deleted or the filesystem is
unmounted, the rule is deleted automatically.  A future enhancement would be to
have the rule survive across directory disruptions.

This is a heavily modified version of a patch originally submitted by Eric
Paris with some ideas from Peter Moody.

Cc: Peter Moody <peter@hda3.com>
Cc: Eric Paris <eparis@redhat.com>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
[PM: minor whitespace clean to satisfy ./scripts/checkpatch]
Signed-off-by: Paul Moore <pmoore@redhat.com>
2015-08-06 16:17:25 -04:00
Linus Torvalds
9ec3a646fe Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull fourth vfs update from Al Viro:
 "d_inode() annotations from David Howells (sat in for-next since before
  the beginning of merge window) + four assorted fixes"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  RCU pathwalk breakage when running into a symlink overmounting something
  fix I_DIO_WAKEUP definition
  direct-io: only inc/dec inode->i_dio_count for file systems
  fs/9p: fix readdir()
  VFS: assorted d_backing_inode() annotations
  VFS: fs/inode.c helpers: d_inode() annotations
  VFS: fs/cachefiles: d_backing_inode() annotations
  VFS: fs library helpers: d_inode() annotations
  VFS: assorted weird filesystems: d_inode() annotations
  VFS: normal filesystems (and lustre): d_inode() annotations
  VFS: security/: d_inode() annotations
  VFS: security/: d_backing_inode() annotations
  VFS: net/: d_inode() annotations
  VFS: net/unix: d_backing_inode() annotations
  VFS: kernel/: d_inode() annotations
  VFS: audit: d_backing_inode() annotations
  VFS: Fix up some ->d_inode accesses in the chelsio driver
  VFS: Cachefiles should perform fs modifications on the top layer only
  VFS: AF_UNIX sockets should call mknod on the top layer only
2015-04-26 17:22:07 -07:00
Linus Torvalds
27cf3a16b2 Merge branch 'upstream' of git://git.infradead.org/users/pcmoore/audit
Pull audit fixes from Paul Moore:
 "Seven audit patches for v4.1, all bug fixes.

  The largest, and perhaps most significant commit helps resolve some
  memory pressure issues related to the inode cache and audit, there are
  also a few small commits which help resolve some timing issues with
  the audit log queue, and the rest fall into the always popular "code
  clean-up" category.

  In general, nothing really substantial, just a nice set of maintenance
  patches"

* 'upstream' of git://git.infradead.org/users/pcmoore/audit:
  audit: Remove condition which always evaluates to false
  audit: reduce mmap_sem hold for mm->exe_file
  audit: consolidate handling of mm->exe_file
  audit: code clean up
  audit: don't reset working wait time accidentally with auditd
  audit: don't lose set wait time on first successful call to audit_log_start()
  audit: move the tree pruning to a dedicated thread
2015-04-22 14:49:23 -07:00
David Howells
3b362157b2 VFS: audit: d_backing_inode() annotations
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-04-15 15:06:55 -04:00
Imre Palik
f1aaf26224 audit: move the tree pruning to a dedicated thread
When file auditing is enabled, during a low memory situation, a memory
allocation with __GFP_FS can lead to pruning the inode cache.  Which can,
in turn lead to audit_tree_freeing_mark() being called.  This can call
audit_schedule_prune(), that tries to fork a pruning thread, and
waits until the thread is created.  But forking needs memory, and the
memory allocations there are done with __GFP_FS.

So we are waiting merrily for some __GFP_FS memory allocations to complete,
while holding some filesystem locks.  This can take a while ...

This patch creates a single thread for pruning the tree from
audit_add_tree_rule(), and thus avoids the deadlock that the on-demand
thread creation can cause.

Reported-by: Matt Wilson <msw@amazon.com>
Cc: Matt Wilson <msw@amazon.com>
Signed-off-by: Imre Palik <imrep@amazon.de>
Reviewed-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <pmoore@redhat.com>
2015-02-23 15:37:59 -05:00
Jan Kara
0809ab69a2 fsnotify: unify inode and mount marks handling
There's a lot of common code in inode and mount marks handling.  Factor it
out to a common helper function.

Signed-off-by: Jan Kara <jack@suse.cz>
Cc: Eric Paris <eparis@redhat.com>
Cc: Heinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 12:42:53 -08:00
Miklos Szeredi
799b601451 audit: keep inode pinned
Audit rules disappear when an inode they watch is evicted from the cache.
This is likely not what we want.

The guilty commit is "fsnotify: allow marks to not pin inodes in core",
which didn't take into account that audit_tree adds watches with a zero
mask.

Adding any mask should fix this.

Fixes: 90b1e7a578 ("fsnotify: allow marks to not pin inodes in core")
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Cc: stable@vger.kernel.org # 2.6.36+
Signed-off-by: Paul Moore <pmoore@redhat.com>
2014-11-11 14:20:22 -05:00
Richard Guy Briggs
2991dd2b01 audit: rename audit_log_remove_rule to disambiguate for trees
Rename audit_log_remove_rule() to audit_tree_log_remove_rule() to avoid
confusion with watch and mark rule removal/changes.

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
2014-10-10 15:30:25 -04:00
Burn Alting
e7df61f4d1 audit: invalid op= values for rules
Various audit events dealing with adding, removing and updating rules result in
invalid values set for the op keys which result in embedded spaces in op=
values.

The invalid values are
        op="add rule"       set in kernel/auditfilter.c
        op="remove rule"    set in kernel/auditfilter.c
        op="remove rule"    set in kernel/audit_tree.c
        op="updated rules"  set in kernel/audit_watch.c
        op="remove rule"    set in kernel/audit_watch.c

Replace the space in the above values with an underscore character ('_').

Coded-by: Burn Alting <burn@swtf.dyndns.org>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
2014-09-23 16:37:53 -04:00
Jan Kara
45a22f4c11 inotify: Fix reporting of cookies for inotify events
My rework of handling of notification events (namely commit 7053aee26a
"fsnotify: do not share events between notification groups") broke
sending of cookies with inotify events. We didn't propagate the value
passed to fsnotify() properly and passed 4 uninitialized bytes to
userspace instead (so it is also an information leak). Sadly I didn't
notice this during my testing because inotify cookies aren't used very
much and LTP inotify tests ignore them.

Fix the problem by passing the cookie value properly.

Fixes: 7053aee26a
Reported-by: Vegard Nossum <vegard.nossum@oracle.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2014-02-18 11:17:17 +01:00
Jan Kara
56b27cf603 fsnotify: remove pointless NULL initializers
We usually rely on the fact that struct members not specified in the
initializer are set to NULL.  So do that with fsnotify function pointers
as well.

Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Eric Paris <eparis@parisplace.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-21 16:19:41 -08:00
Jan Kara
83c4c4b0a3 fsnotify: remove .should_send_event callback
After removing event structure creation from the generic layer there is
no reason for separate .should_send_event and .handle_event callbacks.
So just remove the first one.

Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Eric Paris <eparis@parisplace.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-21 16:19:41 -08:00
Jan Kara
7053aee26a fsnotify: do not share events between notification groups
Currently fsnotify framework creates one event structure for each
notification event and links this event into all interested notification
groups.  This is done so that we save memory when several notification
groups are interested in the event.  However the need for event
structure shared between inotify & fanotify bloats the event structure
so the result is often higher memory consumption.

Another problem is that fsnotify framework keeps path references with
outstanding events so that fanotify can return open file descriptors
with its events.  This has the undesirable effect that filesystem cannot
be unmounted while there are outstanding events - a regression for
inotify compared to a situation before it was converted to fsnotify
framework.  For fanotify this problem is hard to avoid and users of
fanotify should kind of expect this behavior when they ask for file
descriptors from notified files.

This patch changes fsnotify and its users to create separate event
structure for each group.  This allows for much simpler code (~400 lines
removed by this patch) and also smaller event structures.  For example
on 64-bit system original struct fsnotify_event consumes 120 bytes, plus
additional space for file name, additional 24 bytes for second and each
subsequent group linking the event, and additional 32 bytes for each
inotify group for private data.  After the conversion inotify event
consumes 48 bytes plus space for file name which is considerably less
memory unless file names are long and there are several groups
interested in the events (both of which are uncommon).  Fanotify event
fits in 56 bytes after the conversion (fanotify doesn't care about file
names so its events don't have to have it allocated).  A win unless
there are four or more fanotify groups interested in the event.

The conversion also solves the problem with unmount when only inotify is
used as we don't have to grab path references for inotify events.

[hughd@google.com: fanotify: fix corruption preventing startup]
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Eric Paris <eparis@parisplace.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-21 16:19:41 -08:00
Chen Gang
736f3203a0 kernel/audit_tree.c:audit_add_tree_rule(): protect `rule' from kill_rules()
audit_add_tree_rule() must set 'rule->tree = NULL;' firstly, to protect
the rule itself freed in kill_rules().

The reason is when it is killed, the 'rule' itself may have already
released, we should not access it.  one example: we add a rule to an
inode, just at the same time the other task is deleting this inode.

The work flow for adding a rule:

    audit_receive() -> (need audit_cmd_mutex lock)
      audit_receive_skb() ->
        audit_receive_msg() ->
          audit_receive_filter() ->
            audit_add_rule() ->
              audit_add_tree_rule() -> (need audit_filter_mutex lock)
                ...
                unlock audit_filter_mutex
                get_tree()
                ...
                iterate_mounts() -> (iterate all related inodes)
                  tag_mount() ->
                    tag_trunk() ->
                      create_trunk() -> (assume it is 1st rule)
                        fsnotify_add_mark() ->
                          fsnotify_add_inode_mark() ->  (add mark to inode->i_fsnotify_marks)
                        ...
                        get_tree(); (each inode will get one)
                ...
                lock audit_filter_mutex

The work flow for deleting an inode:

    __destroy_inode() ->
     fsnotify_inode_delete() ->
       __fsnotify_inode_delete() ->
        fsnotify_clear_marks_by_inode() ->  (get mark from inode->i_fsnotify_marks)
          fsnotify_destroy_mark() ->
           fsnotify_destroy_mark_locked() ->
             audit_tree_freeing_mark() ->
               evict_chunk() ->
                 ...
                 tree->goner = 1
                 ...
                 kill_rules() ->   (assume current->audit_context == NULL)
                   call_rcu() ->   (rule->tree != NULL)
                     audit_free_rule_rcu() ->
                       audit_free_rule()
                 ...
                 audit_schedule_prune() ->  (assume current->audit_context == NULL)
                   kthread_run() ->    (need audit_cmd_mutex and audit_filter_mutex lock)
                     prune_one() ->    (delete it from prue_list)
                       put_tree(); (match the original get_tree above)

Signed-off-by: Chen Gang <gang.chen@asianux.com>
Cc: Eric Paris <eparis@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-06-12 16:29:46 -07:00
Chen Gang
12b2f117f3 kernel/audit_tree.c: tree will leak memory when failure occurs in audit_trim_trees()
audit_trim_trees() calls get_tree().  If a failure occurs we must call
put_tree().

[akpm@linux-foundation.org: run put_tree() before mutex_lock() for small scalability improvement]
Signed-off-by: Chen Gang <gang.chen@asianux.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric Paris <eparis@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-29 15:54:26 -07:00
Kees Cook
0644ec0cc8 audit: catch possible NULL audit buffers
It's possible for audit_log_start() to return NULL.  Handle it in the
various callers.

Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric Paris <eparis@redhat.com>
Cc: Jeff Layton <jlayton@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Julien Tinnes <jln@google.com>
Cc: Will Drewry <wad@google.com>
Cc: Steve Grubb <sgrubb@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-01-11 14:54:55 -08:00
Lino Sanfilippo
e2a29943e9 fsnotify: pass group to fsnotify_destroy_mark()
In fsnotify_destroy_mark() dont get the group from the passed mark anymore,
but pass the group itself as an additional parameter to the function.

Signed-off-by: Lino Sanfilippo <LinoSanfilippo@gmx.de>
Signed-off-by: Eric Paris <eparis@redhat.com>
2012-12-11 13:44:36 -05:00
Miklos Szeredi
b3e8692b4d audit: clean up refcounting in audit-tree
Drop the initial reference by fsnotify_init_mark early instead of
audit_tree_freeing_mark() at destroy time.

In the cases we destroy the mark before we drop the initial reference we need to
get rid of the get_mark that balances the put_mark in audit_tree_freeing_mark().

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2012-08-15 12:55:22 +02:00
Miklos Szeredi
a2140fc0cb audit: fix refcounting in audit-tree
Refcounting of fsnotify_mark in audit tree is broken.  E.g:

                              refcount
create_chunk
  alloc_chunk                 1
  fsnotify_add_mark           2

untag_chunk
  fsnotify_get_mark           3
  fsnotify_destroy_mark
    audit_tree_freeing_mark   2
  fsnotify_put_mark           1
  fsnotify_put_mark           0
  via destroy_list
    fsnotify_mark_destroy    -1

This was reported by various people as triggering Oops when stopping auditd.

We could just remove the put_mark from audit_tree_freeing_mark() but that would
break freeing via inode destruction.  So this patch simply omits a put_mark
after calling destroy_mark or adds a get_mark before.

The additional get_mark is necessary where there's no other put_mark after
fsnotify_destroy_mark() since it assumes that the caller is holding a reference
(or the inode is keeping the mark pinned, not the case here AFAICS).

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Reported-by: Valentin Avram <aval13@gmail.com>
Reported-by: Peter Moody <pmoody@google.com>
Acked-by: Eric Paris <eparis@redhat.com>
CC: stable@vger.kernel.org
2012-08-15 12:55:22 +02:00
Miklos Szeredi
0fe33aae0e audit: don't free_chunk() after fsnotify_add_mark()
Don't do free_chunk() after fsnotify_add_mark().  That one does a delayed unref
via the destroy list and this results in use-after-free.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Acked-by: Eric Paris <eparis@redhat.com>
CC: stable@vger.kernel.org
2012-08-15 12:55:22 +02:00
David Howells
be34d1a3bc VFS: Make clone_mnt()/copy_tree()/collect_mounts() return errors
copy_tree() can theoretically fail in a case other than ENOMEM, but always
returns NULL which is interpreted by callers as -ENOMEM.  Change it to return
an explicit error.

Also change clone_mnt() for consistency and because union mounts will add new
error cases.

Thanks to Andreas Gruenbacher <agruen@suse.de> for a bug fix.
[AV: folded braino fix by Dan Carpenter]

Original-author: Valerie Aurora <vaurora@redhat.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Cc: Valerie Aurora <valerie.aurora@gmail.com>
Cc: Andreas Gruenbacher <agruen@suse.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-14 16:37:27 +04:00
Lai Jiangshan
3b097c4696 audit_tree,rcu: Convert call_rcu(__put_tree) to kfree_rcu()
The rcu callback __put_tree() just calls a kfree(),
so we use kfree_rcu() instead of the call_rcu(__put_tree).

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric Paris <eparis@redhat.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2011-07-20 14:10:11 -07:00
Lucas De Marchi
25985edced Fix common misspellings
Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
2011-03-31 11:26:23 -03:00
Al Viro
f7a998a949 in untag_chunk() we need to do alloc_chunk() a bit earlier
... while we are not holding spinlocks.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-30 02:18:32 -04:00
Eric Paris
1968f5eed5 fanotify: use both marks when possible
fanotify currently, when given a vfsmount_mark will look up (if it exists)
the corresponding inode mark.  This patch drops that lookup and uses the
mark provided.

Signed-off-by: Eric Paris <eparis@redhat.com>
2010-07-28 10:18:55 -04:00
Eric Paris
ce8f76fb73 fsnotify: pass both the vfsmount mark and inode mark
should_send_event() and handle_event() will both need to look up the inode
event if they get a vfsmount event.  Lets just pass both at the same time
since we have them both after walking the lists in lockstep.

Signed-off-by: Eric Paris <eparis@redhat.com>
2010-07-28 10:18:54 -04:00
Eric Paris
2612abb51b fsnotify: cleanup should_send_event
The change to use srcu and walk the object list rather than the global
fsnotify_group list means that should_send_event is no longer needed for a
number of groups and can be simplified for others.  Do that.

Signed-off-by: Eric Paris <eparis@redhat.com>
2010-07-28 10:18:53 -04:00
Eric Paris
3a9b16b407 fsnotify: send fsnotify_mark to groups in event handling functions
With the change of fsnotify to use srcu walking the marks list instead of
walking the global groups list we now know the mark in question.  The code can
send the mark to the group's handling functions and the groups won't have to
find those marks themselves.

Signed-off-by: Eric Paris <eparis@redhat.com>
2010-07-28 10:18:52 -04:00
Eric Paris
5444e2981c fsnotify: split generic and inode specific mark code
currently all marking is done by functions in inode-mark.c.  Some of this
is pretty generic and should be instead done in a generic function and we
should only put the inode specific code in inode-mark.c

Signed-off-by: Eric Paris <eparis@redhat.com>
2010-07-28 09:58:57 -04:00
Andreas Gruenbacher
3556608709 fsnotify: take inode->i_lock inside fsnotify_find_mark_entry()
All callers to fsnotify_find_mark_entry() except one take and
release inode->i_lock around the call.  Take the lock inside
fsnotify_find_mark_entry() instead.

Signed-off-by: Andreas Gruenbacher <agruen@suse.de>
Signed-off-by: Eric Paris <eparis@redhat.com>
2010-07-28 09:58:54 -04:00
Eric Paris
d07754412f fsnotify: rename fsnotify_find_mark_entry to fsnotify_find_mark
the _entry portion of fsnotify functions is useless.  Drop it.

Signed-off-by: Eric Paris <eparis@redhat.com>
2010-07-28 09:58:53 -04:00