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]>

diff --git a/mm/slub.c b/mm/slub.c
index b364844a1068be41e1419fa02746060af67e92bb..7d6c8b1ccf63afda07c374ff9d4b933f44dbed12 100644 (file)
--- 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)