On Wed, Jan 10, 2018 at 10:31 AM, Christopher Lameter [off-list ref] wrote:

On Tue, 9 Jan 2018, Kees Cook wrote:

quoted

@@ -3823,11 +3825,9 @@ int __check_heap_object(const void *ptr, unsigned long n, struct page *page,

Could we do the check in mm_slab_common.c for all allocators and just have
a small function in each allocators that give you the metadata needed for
the object?

That could be done, but there would still need to be some
implementation-specific checks in the per-implementation side (e.g.
red-zone, etc). I'll work up a patch and see if it's less ugly than
what I've currently got. :)

quoted

+ * carefully audit the whitelist range).
+ */
 int report_usercopy(const char *name, const char *detail, bool to_user,
                  unsigned long offset, unsigned long len)
 {

Should this not be added earlier?

This seemed like the best place to add this since it's where the WARN
is being added, so it's a bit more help for anyone looking at the
code.

-Kees

-- 
Kees Cook
Pixel Security

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