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 <[email protected]>
> Fixes: ceeec0afd684 ("crypto: ccp - Add support for RSA on the CCP")
> Cc: [email protected]
Patch applied. Thanks.
--
Email: Herbert Xu <[email protected]>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
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 <[email protected]>
>> Fixes: ceeec0afd684 ("crypto: ccp - Add support for RSA on the CCP")
>> Cc: [email protected]
>
> Patch applied. Thanks.
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).
Maciej
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 <[email protected]>
>>> Fixes: ceeec0afd684 ("crypto: ccp - Add support for RSA on the CCP")
>>> Cc: [email protected]
>>
>> Patch applied. Thanks.
>
> 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).
>
> Maciej
>
I commented on that one here:
https://marc.info/?l=linux-crypto-vger&m=151986452422791&w=2
Effectively a NACK. We are a reviewing a proposed patch right now.
On 03.03.2018 00:49, Hook, Gary wrote:
> 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 <[email protected]>
>>>> Fixes: ceeec0afd684 ("crypto: ccp - Add support for RSA on the CCP")
>>>> Cc: [email protected]
>>>
>>> Patch applied. Thanks.
>>
>> 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).
>>
>> Maciej
>>
>
>
> I commented on that one here:
> https://marc.info/?l=linux-crypto-vger&m=151986452422791&w=2
>
> Effectively a NACK. We are a reviewing a proposed patch right now.
Your earlier comment referred to the third patch from this series.
My message above was about the first one.
Maciej
On 03/02/2018 05:58 PM, Maciej S. Szmigiero wrote:
> On 03.03.2018 00:49, Hook, Gary wrote:
>> On 3/2/2018 5:15 PM, Maciej S. Szmigiero wrote:
>>>
>>> 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).
>>>
>>> Maciej
>>>
>>
>>
>> I commented on that one here:
>> https://marc.info/?l=linux-crypto-vger&m=151986452422791&w=2
>>
>> Effectively a NACK. We are a reviewing a proposed patch right now.
>
> Your earlier comment referred to the third patch from this series.
> My message above was about the first one.
Apologies; my mistake.
On Sat, Mar 03, 2018 at 12:15:20AM +0100, Maciej S. Szmigiero wrote:
>
> 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).
That normally goes through the security tree.
Cheers,
--
Email: Herbert Xu <[email protected]>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt