slub: Fix kmem_ptr_validate() for non-kernel pointers

As suggested by Linus, fix up kmem_ptr_validate() to handle non-kernel pointers more graciously. The patch changes kmem_ptr_validate() to use the newly introduced kern_ptr_validate() helper to check that a pointer is a valid kernel pointer before we attempt to convert it into a 'struct page'. Cc: Andrew Morton <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Matt Mackall <[email protected]> Cc: Nick Piggin <[email protected]> Signed-off-by: Pekka Enberg <[email protected]> Acked-by: Christoph Lameter <[email protected]> Acked-by: David Rientjes <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
RyanHsu · Apr 9, 2010 · d3e06e2 · d3e06e2
1 parent fc1c183
commit d3e06e2
Showing 1 changed file with 3 additions and 0 deletions.
diff --git a/mm/slub.c b/mm/slub.c
@@ -2386,6 +2386,9 @@ int kmem_ptr_validate(struct kmem_cache *s, const void *object)
 {
 	struct page *page;
 
+	if (!kern_ptr_validate(object, s->size))
+		return 0;
+
 	page = get_object_page(object);
 
 	if (!page || s != page->slab)