From: Ard Biesheuvel <ard.biesheuvel@linaro.org>
To: Eric Biggers <ebiggers@kernel.org>
Cc: "open list:HARDWARE RANDOM NUMBER GENERATOR CORE"
<linux-crypto@vger.kernel.org>,
Herbert Xu <herbert@gondor.apana.org.au>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
"Jason A . Donenfeld" <Jason@zx2c4.com>,
stable <stable@vger.kernel.org>
Subject: Re: [RFC/RFT PATCH 07/15] crypto: arm64/aes-neonbs - fix returning final keystream block
Date: Thu, 24 Jan 2019 13:11:23 +0100 [thread overview]
Message-ID: <CAKv+Gu_6ZhXVKZwgkiSh0ZvvgjXGS+ygz9b6E0QmCP8ViJrbmw@mail.gmail.com> (raw)
In-Reply-To: <20190123224926.250525-8-ebiggers@kernel.org>
On Wed, 23 Jan 2019 at 23:52, Eric Biggers <ebiggers@kernel.org> wrote:
>
> From: Eric Biggers <ebiggers@google.com>
>
> The arm64 NEON bit-sliced implementation of AES-CTR fails the improved
> skcipher tests because it sometimes produces the wrong ciphertext. The
> bug is that the final keystream block isn't returned from the assembly
> code when the number of non-final blocks is zero. This can happen if
> the input data ends a few bytes after a page boundary. In this case the
> last bytes get "encrypted" by XOR'ing them with uninitialized memory.
>
> Fix the assembly code to return the final keystream block when needed.
>
> Fixes: 88a3f582bea9 ("crypto: arm64/aes - don't use IV buffer to return final keystream block")
> Cc: <stable@vger.kernel.org> # v4.11+
> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
> Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
> ---
> arch/arm64/crypto/aes-neonbs-core.S | 8 ++++++--
> 1 file changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/arch/arm64/crypto/aes-neonbs-core.S b/arch/arm64/crypto/aes-neonbs-core.S
> index e613a87f8b53..8432c8d0dea6 100644
> --- a/arch/arm64/crypto/aes-neonbs-core.S
> +++ b/arch/arm64/crypto/aes-neonbs-core.S
> @@ -971,18 +971,22 @@ CPU_LE( rev x8, x8 )
>
> 8: next_ctr v0
> st1 {v0.16b}, [x24]
> - cbz x23, 0f
> + cbz x23, .Lctr_done
>
> cond_yield_neon 98b
> b 99b
>
> -0: frame_pop
> +.Lctr_done:
> + frame_pop
> ret
>
> /*
> * If we are handling the tail of the input (x6 != NULL), return the
> * final keystream block back to the caller.
> */
> +0: cbz x25, 8b
> + st1 {v0.16b}, [x25]
> + b 8b
> 1: cbz x25, 8b
> st1 {v1.16b}, [x25]
> b 8b
> --
> 2.20.1.321.g9e740568ce-goog
>
prev parent reply other threads:[~2019-01-24 12:11 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20190123224926.250525-1-ebiggers@kernel.org>
2019-01-23 22:49 ` [RFC/RFT PATCH 01/15] crypto: aegis - fix handling chunked inputs Eric Biggers
2019-01-23 22:49 ` [RFC/RFT PATCH 02/15] crypto: morus " Eric Biggers
2019-01-31 9:05 ` Ondrej Mosnacek
2019-02-01 5:25 ` Eric Biggers
2019-01-23 22:49 ` [RFC/RFT PATCH 03/15] crypto: x86/aegis - fix handling chunked inputs and MAY_SLEEP Eric Biggers
2019-01-23 22:49 ` [RFC/RFT PATCH 04/15] crypto: x86/morus " Eric Biggers
2019-01-23 22:49 ` [RFC/RFT PATCH 05/15] crypto: x86/aesni-gcm - fix crash on empty plaintext Eric Biggers
2019-01-23 22:49 ` [RFC/RFT PATCH 06/15] crypto: ahash - fix another early termination in hash walk Eric Biggers
2019-01-23 22:49 ` [RFC/RFT PATCH 07/15] crypto: arm64/aes-neonbs - fix returning final keystream block Eric Biggers
2019-01-24 12:11 ` Ard Biesheuvel [this message]
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