Re: [PATCH 1/9] mm: Hardened usercopy

On Wed, 2016-07-06 at 15:25 -0700, Kees Cook wrote:

+	/* Allow kernel rodata region (if not marked as Reserved).
*/
+	if (ptr >= (const void *)__start_rodata &&
+	    end <= (const void *)__end_rodata)
+		return NULL;

One comment here.

__check_object_size gets "to_user" as an argument.

It may make sense to pass that to check_heap_object, and
only allow copy_to_user from rodata, never copy_from_user,
since that section should be read only.

+void __check_object_size(const void *ptr, unsigned long n, bool
to_user)
+{

-- 

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