GIT 1c818dd91b3d532f182a35138fd12c3a2063fda5 git+ssh://master.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6.git#for-mm

commit 1c818dd91b3d532f182a35138fd12c3a2063fda5
Author: Christoph Lameter <clameter@sgi.com>
Date:   Wed May 28 10:32:22 2008 -0700

    slub: Add check for kfree() of non slab objects.
    
    We can detect kfree()s on non slab objects by checking for PageCompound().
    Works in the same way as for ksize. This helped me catch an invalid
    kfree().
    
    Signed-off-by: Christoph Lameter <clameter@sgi.com>
    Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
 mm/slub.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/mm/slub.c b/mm/slub.c
index 0987d1c..5b4283c 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -2765,6 +2765,7 @@ void kfree(const void *x)
 
 	page = virt_to_head_page(x);
 	if (unlikely(!PageSlab(page))) {
+		BUG_ON(!PageCompound(page));
 		put_page(page);
 		return;
 	}