Date: Wed, 10 Jan 2018 12:31:47 -0600 (CST)
From: Christopher Lameter <cl@linux.com>
To: Kees Cook <keescook@chromium.org>
cc: linux-kernel@vger.kernel.org, David Windsor <dave@nullcore.net>,
        Pekka Enberg <penberg@kernel.org>,
        David Rientjes <rientjes@google.com>,
        Joonsoo Kim <iamjoonsoo.kim@lge.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Laura Abbott <labbott@redhat.com>,
        Ingo Molnar <mingo@kernel.org>,
        Mark Rutland <mark.rutland@arm.com>, linux-mm@kvack.org,
        linux-xfs@vger.kernel.org,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Alexander Viro <viro@zeniv.linux.org.uk>,
        Andy Lutomirski <luto@kernel.org>,
        Christoph Hellwig <hch@infradead.org>,
        "David S. Miller" <davem@davemloft.net>,
        "Martin K. Petersen" <martin.petersen@oracle.com>,
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Subject: Re: [PATCH 05/36] usercopy: WARN() on slab cache usercopy region
 violations
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On Tue, 9 Jan 2018, Kees Cook wrote:

> @@ -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?

> + * 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?