slub: Fix a crash during slabinfo -v

Commit f7cb1933621bce66a77f690776a16fe3ebbc4d58 ("SLUB: Pass active
and inactive redzone flags instead of boolean to debug functions")
missed two instances of check_object(). This caused a lot of warnings
during 'slabinfo -v' finally leading to a crash:

  BUG ext4_xattr: Freepointer corrupt
  ...
  BUG buffer_head: Freepointer corrupt
  ...
  BUG ext4_alloc_context: Freepointer corrupt
  ...
  ...
  BUG: unable to handle kernel NULL pointer dereference at 0000000000000008
  IP: [<ffffffff810a291f>] file_sb_list_del+0x1c/0x35
  PGD 79d78067 PUD 79e67067 PMD 0
  Oops: 0002 [#1] SMP
  last sysfs file: /sys/kernel/slab/:t-0000192/validate

This patch fixes the problem by converting the two missed instances.

Acked-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Tero Roponen <tero.roponen@gmail.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>

diff --git a/mm/slub.c b/mm/slub.c
index 7796a04..48d82a5 100644 (file)
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -3417,13 +3417,13 @@ static int validate_slab(struct kmem_cache *s, struct page *page,
 
        for_each_free_object(p, s, page->freelist) {
                set_bit(slab_index(p, s, addr), map);
-               if (!check_object(s, page, p, 0))
+               if (!check_object(s, page, p, SLUB_RED_INACTIVE))
                        return 0;
        }
 
        for_each_object(p, s, addr, page->objects)
                if (!test_bit(slab_index(p, s, addr), map))
-                       if (!check_object(s, page, p, 1))
+                       if (!check_object(s, page, p, SLUB_RED_ACTIVE))
                                return 0;
        return 1;
 }