On 3/2/2018 5:15 PM, Maciej S. Szmigiero wrote:
On 02.03.2018 17:44, Herbert Xu wrote:
On Sat, Feb 24, 2018 at 05:03:21PM +0100, Maciej S. Szmigiero wrote:
rsa-pkcs1pad uses a value returned from a RSA implementation max_size
callback as a size of an input buffer passed to the RSA implementation for
encrypt and sign operations.

CCP RSA implementation uses a hardware input buffer which size depends only
on the current RSA key length, so it should return this key length in
the max_size callback, too.
This also matches what the kernel software RSA implementation does.

Previously, the value returned from this callback was always the maximum
RSA key size the CCP hardware supports.
This resulted in this huge buffer being passed by rsa-pkcs1pad to CCP even
for smaller key sizes and then in a buffer overflow when ccp_run_rsa_cmd()
tried to copy this large input buffer into a RSA key length-sized hardware
input buffer.

Signed-off-by: Maciej S. Szmigiero <m...@maciej.szmigiero.name>
Fixes: ceeec0afd684 ("crypto: ccp - Add support for RSA on the CCP")
Cc: sta...@vger.kernel.org

Patch applied.  Thanks.


However, what about the first patch from this series?
Without it, while it no longer should cause a buffer overflow, in-kernel
X.509 certificate verification will still fail with CCP driver loaded
(since CCP RSA implementation has a higher priority than the software
RSA implementation).


I commented on that one here:

Effectively a NACK. We are a reviewing a proposed patch right now.

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