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  1. 05 1月, 2009 3 次提交
  3. 16 11月, 2008 1 次提交
    • A
      Fix inotify watch removal/umount races · 8f7b0ba1
      由 Al Viro 提交于 
      Inotify watch removals suck violently.

To kick the watch out we need (in this order) inode->inotify_mutex and
ih->mutex.  That's fine if we have a hold on inode; however, for all
other cases we need to make damn sure we don't race with umount.  We can
*NOT* just grab a reference to a watch - inotify_unmount_inodes() will
happily sail past it and we'll end with reference to inode potentially
outliving its superblock.

Ideally we just want to grab an active reference to superblock if we
can; that will make sure we won't go into inotify_umount_inodes() until
we are done.  Cleanup is just deactivate_super().

However, that leaves a messy case - what if we *are* racing with
umount() and active references to superblock can't be acquired anymore?
We can bump ->s_count, grab ->s_umount, which will almost certainly wait
until the superblock is shut down and the watch in question is pining
for fjords.  That's fine, but there is a problem - we might have hit the
window between ->s_active getting to 0 / ->s_count - below S_BIAS (i.e.
the moment when superblock is past the point of no return and is heading
for shutdown) and the moment when deactivate_super() acquires
->s_umount.

We could just do drop_super() yield() and retry, but that's rather
antisocial and this stuff is luser-triggerable.  OTOH, having grabbed
->s_umount and having found that we'd got there first (i.e.  that
->s_root is non-NULL) we know that we won't race with
inotify_umount_inodes().

So we could grab a reference to watch and do the rest as above, just
with drop_super() instead of deactivate_super(), right? Wrong.  We had
to drop ih->mutex before we could grab ->s_umount.  So the watch
could've been gone already.

That still can be dealt with - we need to save watch->wd, do idr_find()
and compare its result with our pointer.  If they match, we either have
the damn thing still alive or we'd lost not one but two races at once,
the watch had been killed and a new one got created with the same ->wd
at the same address.  That couldn't have happened in inotify_destroy(),
but inotify_rm_wd() could run into that.  Still, "new one got created"
is not a problem - we have every right to kill it or leave it alone,
whatever's more convenient.

So we can use idr_find(...) == watch && watch->inode->i_sb == sb as
"grab it and kill it" check.  If it's been our original watch, we are
fine, if it's a newcomer - nevermind, just pretend that we'd won the
race and kill the fscker anyway; we are safe since we know that its
superblock won't be going away.

And yes, this is far beyond mere "not very pretty"; so's the entire
concept of inotify to start with.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Acked-by: NGreg KH <greg@kroah.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      8f7b0ba1
  5. 02 8月, 2008 1 次提交
  7. 25 6月, 2008 2 次提交
  9. 29 4月, 2008 1 次提交
  11. 28 4月, 2008 4 次提交
    • A
      [PATCH] new predicate - AUDIT_FILETYPE · 8b67dca9
      由 Al Viro 提交于 
      Argument is S_IF... | <index>, where index is normally 0 or 1.
Triggers if chosen element of ctx->names[] is present and the
mode of object in question matches the upper bits of argument.
I.e. for things like "is the argument of that chmod a directory",
etc.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      8b67dca9
    • H
      [PATCH 2/2] audit: fix sparse shadowed variable warnings · 7719e437
      由 Harvey Harrison 提交于 
      Use msglen as the identifier.
kernel/audit.c:724:10: warning: symbol 'len' shadows an earlier one
kernel/audit.c:575:8: originally declared here

Don't use ino_f to check the inode field at the end of the functions.
kernel/auditfilter.c:429:22: warning: symbol 'f' shadows an earlier one
kernel/auditfilter.c:420:21: originally declared here
kernel/auditfilter.c:542:22: warning: symbol 'f' shadows an earlier one
kernel/auditfilter.c:529:21: originally declared here

i always used as a counter for a for loop and initialized to zero before
use.  Eliminate the inner i variables.
kernel/auditsc.c:1295:8: warning: symbol 'i' shadows an earlier one
kernel/auditsc.c:1152:6: originally declared here
kernel/auditsc.c:1320:7: warning: symbol 'i' shadows an earlier one
kernel/auditsc.c:1152:6: originally declared here
Signed-off-by: NHarvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      7719e437
    • H
      [PATCH 1/2] audit: move extern declarations to audit.h · c782f242
      由 Harvey Harrison 提交于 
      Leave audit_sig_{uid|pid|sid} protected by #ifdef CONFIG_AUDITSYSCALL.

Noticed by sparse:
kernel/audit.c:73:6: warning: symbol 'audit_ever_enabled' was not declared. Should it be static?
kernel/audit.c:100:8: warning: symbol 'audit_sig_uid' was not declared. Should it be static?
kernel/audit.c:101:8: warning: symbol 'audit_sig_pid' was not declared. Should it be static?
kernel/audit.c:102:6: warning: symbol 'audit_sig_sid' was not declared. Should it be static?
kernel/audit.c:117:23: warning: symbol 'audit_ih' was not declared. Should it be static?
kernel/auditfilter.c:78:18: warning: symbol 'audit_filter_list' was not declared. Should it be static?
Signed-off-by: NHarvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      c782f242
    • E
      Audit: collect sessionid in netlink messages · 2532386f
      由 Eric Paris 提交于 
      Previously I added sessionid output to all audit messages where it was
available but we still didn't know the sessionid of the sender of
netlink messages.  This patch adds that information to netlink messages
so we can audit who sent netlink messages.
Signed-off-by: NEric Paris <eparis@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      2532386f
  13. 19 4月, 2008 3 次提交
  15. 15 2月, 2008 2 次提交
  17. 02 2月, 2008 1 次提交
  19. 21 10月, 2007 1 次提交
    • A
      [PATCH] audit: watching subtrees · 74c3cbe3
      由 Al Viro 提交于 
      New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is.  Limitations:
	* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
	* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
	* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there.  New command
tells audit to recalculate the trees, trimming such sources of false
positives.

Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      74c3cbe3
  21. 19 10月, 2007 1 次提交
  23. 22 7月, 2007 2 次提交
  25. 18 7月, 2007 1 次提交
    • J
      kernel/auditfilter: kill bogus uninit'd-var compiler warning · 6f686d3d
      由 Jeff Garzik 提交于 
      Kill this warning...

kernel/auditfilter.c: In function ‘audit_receive_filter’:
kernel/auditfilter.c:1213: warning: ‘ndw’ may be used uninitialized in this function
kernel/auditfilter.c:1213: warning: ‘ndp’ may be used uninitialized in this function

...with a simplification of the code.  audit_put_nd() can accept NULL
arguments, just like kfree().  It is cleaner to init two existing vars
to NULL, remove the redundant test variable 'putnd_needed' branches, and call
audit_put_nd() directly.

As a desired side effect, the warning goes away.
Signed-off-by: NJeff Garzik <jeff@garzik.org>
      6f686d3d
  27. 24 6月, 2007 1 次提交
  29. 16 5月, 2007 1 次提交
  31. 11 5月, 2007 1 次提交
    • A
      [PATCH] audit signal recipients · e54dc243
      由 Amy Griffis 提交于 
      When auditing syscalls that send signals, log the pid and security
context for each target process. Optimize the data collection by
adding a counter for signal-related rules, and avoiding allocating an
aux struct unless we have more than one target process. For process
groups, collect pid/context data in blocks of 16. Move the
audit_signal_info() hook up in check_kill_permission() so we audit
attempts where permission is denied.
Signed-off-by: NAmy Griffis <amy.griffis@hp.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      e54dc243
  33. 18 2月, 2007 1 次提交
  35. 12 2月, 2007 1 次提交
  37. 23 12月, 2006 1 次提交
  39. 08 12月, 2006 1 次提交
  41. 04 10月, 2006 1 次提交
    • E
      [PATCH] arch filter lists with < or > should not be accepted · 4b8a311b
      由 Eric Paris 提交于 
      Currently the kernel audit system represents arch's as numbers and will
gladly accept comparisons between archs using >, <, >=, <= when the only
thing that makes sense is = or !=.  I'm told that the next revision of
auditctl will do this checking but this will provide enforcement in the
kernel even for old userspace.  A simple command to show the issue would
be to run

auditctl -d entry,always -F arch>i686 -S chmod

with this patch the kernel will reject this with -EINVAL

Please comment/ack/nak as soon as possible.

-Eric

 kernel/auditfilter.c |    9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      4b8a311b
  43. 26 9月, 2006 1 次提交
  45. 12 9月, 2006 3 次提交
  47. 03 8月, 2006 2 次提交
  49. 01 7月, 2006 3 次提交