Skip to content

Commit 0f8f809

Browse files
Christoph Lameterpenberg
authored andcommitted
slab: fix init_lock_keys
Some architectures (e.g. powerpc built with CONFIG_PPC_256K_PAGES=y CONFIG_FORCE_MAX_ZONEORDER=11) get PAGE_SHIFT + MAX_ORDER > 26. In 3.10 kernels, CONFIG_LOCKDEP=y with PAGE_SHIFT + MAX_ORDER > 26 makes init_lock_keys() dereference beyond kmalloc_caches[26]. This leads to an unbootable system (kernel panic at initializing SLAB) if one of kmalloc_caches[26...PAGE_SHIFT+MAX_ORDER-1] is not NULL. Fix this by making sure that init_lock_keys() does not dereference beyond kmalloc_caches[26] arrays. Signed-off-by: Christoph Lameter <cl@linux.com> Reported-by: Tetsuo Handa <penguin-kernel@I-Love.SAKURA.ne.jp> Cc: Pekka Enberg <penberg@kernel.org> Cc: <stable@vger.kernel.org> [3.10.x] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Pekka Enberg <penberg@kernel.org>
1 parent a6d7815 commit 0f8f809

File tree

1 file changed

+1
-1
lines changed

1 file changed

+1
-1
lines changed

mm/slab.c

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -565,7 +565,7 @@ static void init_node_lock_keys(int q)
565565
if (slab_state < UP)
566566
return;
567567

568-
for (i = 1; i < PAGE_SHIFT + MAX_ORDER; i++) {
568+
for (i = 1; i <= KMALLOC_SHIFT_HIGH; i++) {
569569
struct kmem_cache_node *n;
570570
struct kmem_cache *cache = kmalloc_caches[i];
571571

0 commit comments

Comments
 (0)