[PATCH 1/2] crypto: arm/aes-ctr: fix NULL dereference in tail processing

[Herbert Xu]

On Tue, Sep 13, 2016 at 09:48:52AM +0100, Ard Biesheuvel wrote:
> The AES-CTR glue code avoids calling into the blkcipher API for the
> tail portion of the walk, by comparing the remainder of walk.nbytes
> modulo AES_BLOCK_SIZE with the residual nbytes, and jumping straight
> into the tail processing block if they are equal. This tail processing
> block checks whether nbytes != 0, and does nothing otherwise.
> 
> However, in case of an allocation failure in the blkcipher layer, we
> may enter this code with walk.nbytes == 0, while nbytes > 0. In this
> case, we should not dereference the source and destination pointers,
> since they may be NULL. So instead of checking for nbytes != 0, check
> for (walk.nbytes % AES_BLOCK_SIZE) != 0, which implies the former in
> non-error conditions.
> 
> Fixes: 86464859cc77 ("crypto: arm - AES in ECB/CBC/CTR/XTS modes using ARMv8 Crypto Extensions")
> Reported-by: xiakaixu <xiakaixu at huawei.com>
> Signed-off-by: Ard Biesheuvel <ard.biesheuvel at linaro.org>
> ---

Both patches applied.  Thanks.
-- 
Email: Herbert Xu <herbert at gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
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