Re: [PATCH 1/4] crypto: s5p-sss - Close possible race for completed requests

[Bartlomiej Zolnierkiewicz]

On Friday, March 17, 2017 04:49:19 PM Krzysztof Kozlowski wrote:
> Driver is capable of handling only one request at a time and it stores
> it in its state container struct s5p_aes_dev.  This stored request must be
> protected between concurrent invocations (e.g. completing current
> request and scheduling new one).  Combination of lock and "busy" field
> is used for that purpose.
> 
> When "busy" field is true, the driver will not accept new request thus
> it will not overwrite currently handled data.
> 
> However commit 28b62b145868 ("crypto: s5p-sss - Fix spinlock recursion
> on LRW(AES)") moved some of the write to "busy" field out of a lock
> protected critical section.  This might lead to potential race between
> completing current request and scheduling a new one.  Effectively the
> request completion might try to operate on new crypto request.
> 
> Cc: <stable@xxxxxxxxxxxxxxx> # v4.10.x
> Fixes: 28b62b145868 ("crypto: s5p-sss - Fix spinlock recursion on LRW(AES)")
> Signed-off-by: Krzysztof Kozlowski <krzk@xxxxxxxxxx>

Reviewed-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@xxxxxxxxxxx>

Best regards,
--
Bartlomiej Zolnierkiewicz
Samsung R&D Institute Poland
Samsung Electronics