Re: [PATCH] crypto: x86/aes-ni - check walk.nbytes instead of err

From: Herbert Xu
Date: Thu Sep 16 2021 - 23:21:59 EST


On Sat, Sep 11, 2021 at 04:37:59PM +0530, Shreyansh Chouhan wrote:
> In the code for xts_crypt(), we check for the err value returned by
> skcipher_walk_virt() and return from the function if it is non zero.
> However, skcipher_walk_virt() can set walk.nbytes to 0, which would cause
> us to call kernel_fpu_begin(), and then skip the kernel_fpu_end() call.
>
> This patch checks for the walk.nbytes value instead, and returns if
> walk.nbytes is 0. This prevents us from calling kernel_fpu_begin() in
> the first place and also covers the case of having a non zero err value
> returned from skcipher_walk_virt().
>
> Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
> Signed-off-by: Shreyansh Chouhan <chouhan.shreyansh630@xxxxxxxxx>
> ---
> arch/x86/crypto/aesni-intel_glue.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)

Patch applied. Thanks.
--
Email: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
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