linux/include
Mel Gorman 04a30bd9dc mempolicy: fix a race in shared_policy_replace()
commit b22d127a39 upstream.

shared_policy_replace() use of sp_alloc() is unsafe.  1) sp_node cannot
be dereferenced if sp->lock is not held and 2) another thread can modify
sp_node between spin_unlock for allocating a new sp node and next
spin_lock.  The bug was introduced before 2.6.12-rc2.

Kosaki's original patch for this problem was to allocate an sp node and
policy within shared_policy_replace and initialise it when the lock is
reacquired.  I was not keen on this approach because it partially
duplicates sp_alloc().  As the paths were sp->lock is taken are not that
performance critical this patch converts sp->lock to sp->mutex so it can
sleep when calling sp_alloc().

[kosaki.motohiro@jp.fujitsu.com: Original patch]
Signed-off-by: Mel Gorman <mgorman@suse.de>
Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reviewed-by: Christoph Lameter <cl@linux.com>
Cc: Josh Boyer <jwboyer@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-13 05:38:56 +09:00
..
acpi Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux 2012-05-05 10:06:06 -07:00
asm-generic mutex: Place lock in contended state after fastpath_lock failure 2012-10-02 10:30:21 -07:00
crypto crypto: user - Fix lookup of algorithms with IV generator 2012-03-29 19:52:47 +08:00
drm drm: Check for invalid cursor flags 2012-10-02 10:30:23 -07:00
keys
linux mempolicy: fix a race in shared_policy_replace() 2012-10-13 05:38:56 +09:00
math-emu
media Merge branch 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media 2012-05-14 11:23:37 -07:00
misc
mtd
net xfrm: Workaround incompatibility of ESN and async crypto 2012-10-13 05:38:40 +09:00
pcmcia
rdma
rxrpc
scsi SCSI: libsas: fix taskfile corruption in sas_ata_qc_fill_rtf 2012-07-16 09:04:37 -07:00
sound ALSA: hda - hide HDMI/ELD printks unless snd.debug=2 2012-04-10 14:53:55 +02:00
target target: Add generation of LOGICAL BLOCK ADDRESS OUT OF RANGE 2012-08-09 08:31:26 -07:00
trace tracing: Don't call page_to_pfn() if page is NULL 2012-10-02 10:30:08 -07:00
video Merge branch 'platforms' of git://git.linaro.org/people/rmk/linux-arm 2012-03-27 18:17:02 -07:00
xen xen/m2p: do not reuse kmap_op->dev_bus_addr 2012-10-02 10:30:06 -07:00
Kbuild