linux-toradex.git/fs, branch v3.6.1

coredump: prevent double-free on an error path in core dumper

2012-10-07T15:39:34+00:00

commit f34f9d186df35e5c39163444c43b4fc6255e39c5 upstream.

In !CORE_DUMP_USE_REGSET case, if elf_note_info_init fails to allocate
memory for info->fields, it frees already allocated stuff and returns
error to its caller, fill_note_info.  Which in turn returns error to its
caller, elf_core_dump.  Which jumps to cleanup label and calls
free_note_info, which will happily try to free all info->fields again.
BOOM.

This is the fix.

Signed-off-by: Oleg Nesterov 
Signed-off-by: Denys Vlasenko 
Cc: Venu Byravarasu 
Signed-off-by: Andrew Morton 
Signed-off-by: Greg Kroah-Hartman

vfs: dcache: fix deadlock in tree traversal

2012-09-30T00:41:40+00:00

IBM reported a deadlock in select_parent().  This was found to be caused
by taking rename_lock when already locked when restarting the tree
traversal.

There are two cases when the traversal needs to be restarted:

 1) concurrent d_move(); this can only happen when not already locked,
    since taking rename_lock protects against concurrent d_move().

 2) racing with final d_put() on child just at the moment of ascending
    to parent; rename_lock doesn't protect against this rare race, so it
    can happen when already locked.

Because of case 2, we need to be able to handle restarting the traversal
when rename_lock is already held.  This patch fixes all three callers of
try_to_ascend().

IBM reported that the deadlock is gone with this patch.

[ I rewrote the patch to be smaller and just do the "goto again" if the
  lock was already held, but credit goes to Miklos for the real work.
   - Linus ]

Signed-off-by: Miklos Szeredi 
Cc: Al Viro 
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2012-09-28T17:02:53+00:00

Pull vfs fixes from Al Viro:
 "A couple of fixes; one for automount/lazy umount race, another a
  classic "we don't protect the refcount transition to zero with the
  lock that protects looking for object in hash" kind of crap in lockd."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  close the race in nlmsvc_free_block()
  do_add_mount()/umount -l races

trivial select_parent documentation fix

2012-09-27T22:43:08+00:00

"Search list for X" sounds like you're trying to find X on a list.

Signed-off-by: J. Bruce Fields 
Signed-off-by: Linus Torvalds

close the race in nlmsvc_free_block()

2012-09-23T00:48:20+00:00

we need to grab mutex before the reference counter reaches 0

Signed-off-by: Al Viro

do_add_mount()/umount -l races

2012-09-23T00:48:18+00:00

normally we deal with lock_mount()/umount races by checking that
mountpoint to be is still in our namespace after lock_mount() has
been done.  However, do_add_mount() skips that check when called
with MNT_SHRINKABLE in flags (i.e. from finish_automount()).  The
reason is that ->mnt_ns may be a temporary namespace created exactly
to contain automounts a-la NFS4 referral handling.  It's not the
namespace of the caller, though, so check_mnt() would fail here.
We still need to check that ->mnt_ns is non-NULL in that case,
though.

Signed-off-by: Al Viro

Merge branch 'for-linus' of git://git.samba.org/sfrench/cifs-2.6

2012-09-22T19:36:57+00:00

Pull cifs fix from Steve French.

* 'for-linus' of git://git.samba.org/sfrench/cifs-2.6:
  cifs: fix return value in cifsConvertToUTF16

Merge tag 'for-linus-v3.6-rc7' of git://oss.sgi.com/xfs/xfs

2012-09-21T19:43:01+00:00

Pull xfs bugfixes from Ben Myers:
 - fix a regression related to xfs_sync_worker racing with unmount.
 - fix a race while discarding xfs buffers.

* tag 'for-linus-v3.6-rc7' of git://oss.sgi.com/xfs/xfs:
  xfs: stop the sync worker before xfs_unmountfs
  xfs: fix race while discarding buffers [V4]

debugfs: fix u32_array race in format_array_alloc

2012-09-21T18:48:05+00:00

The format_array_alloc() function is fundamentally racy, in that it
prints the array twice: once to figure out how much space to allocate
for the buffer, and the second time to actually print out the data.

If any of the array contents changes in between, the allocation size may
be wrong, and the end result may be truncated in odd ways.

Just don't do it.  Allocate a maximum-sized array up-front, and just
format the array contents once.  The only user of the u32_array
interfaces is the Xen spinlock statistics code, and it has 31 entries in
the arrays, so the maximum size really isn't that big, and the end
result is much simpler code without the bug.

Signed-off-by: Linus Torvalds

debugfs: fix race in u32_array_read and allocate array at open

2012-09-21T17:28:17+00:00

u32_array_open() is racy when multiple threads read from a file with a
seek position of zero, i.e. when two or more simultaneous reads are
occurring after the non-seekable files are created.  It is possible that
file->private_data is double-freed because the threads races between

	kfree(file->private-data);

and

	file->private_data = NULL;

The fix is to only do format_array_alloc() when the file is opened and
free it when it is closed.

Note that because the file has always been non-seekable, you can't open
it and read it multiple times anyway, so the data has always been
generated just once.  The difference is that now it is generated at open
time rather than at the time of the first read, and that avoids the
race.

Reported-by: Dave Jones 
Acked-by: Konrad Rzeszutek Wilk 
Tested-by: Raghavendra 
Signed-off-by: David Rientjes 
Signed-off-by: Linus Torvalds