Slab allocators: fail if ksize is called with a NULL parameter
A NULL pointer means that the object was not allocated. One cannot
determine the size of an object that has not been allocated. Currently we
return 0 but we really should BUG() on attempts to determine the size of
something nonexistent.
krealloc() interprets NULL to mean a zero sized object. Handle that
separately in krealloc().
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Matt Mackall <mpm@selenic.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/util.c b/mm/util.c
index bf340d8..5f64026 100644
--- a/mm/util.c
+++ b/mm/util.c
@@ -81,14 +81,16 @@
void *krealloc(const void *p, size_t new_size, gfp_t flags)
{
void *ret;
- size_t ks;
+ size_t ks = 0;
if (unlikely(!new_size)) {
kfree(p);
return ZERO_SIZE_PTR;
}
- ks = ksize(p);
+ if (p)
+ ks = ksize(p);
+
if (ks >= new_size)
return (void *)p;