Linux cryptographic layer development
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From: Eric Biggers <ebiggers@kernel.org>
To: Ard Biesheuvel <ardb@kernel.org>
Cc: linux-crypto@vger.kernel.org, herbert@gondor.apana.org.au
Subject: Re: [PATCH] crypto: arm64/poly1305-neon - reorder PAC authentication with SP update
Date: Mon, 26 Oct 2020 16:03:23 -0700	[thread overview]
Message-ID: <20201026230323.GA1947033@gmail.com> (raw)
In-Reply-To: <20201026230027.25813-1-ardb@kernel.org>

On Tue, Oct 27, 2020 at 12:00:27AM +0100, Ard Biesheuvel wrote:
> PAC pointer authentication signs the return address against the value
> of the stack pointer, to prevent stack overrun exploits from corrupting
> the control flow. However, this requires that the AUTIASP is issued with
> SP holding the same value as it held when the PAC value was generated.
> The Poly1305 NEON code got this wrong, resulting in crashes on PAC
> capable hardware.
> 
> Fixes: f569ca164751 ("crypto: arm64/poly1305 - incorporate OpenSSL/CRYPTOGAMS ...")
> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
> ---
>  arch/arm64/crypto/poly1305-armv8.pl       | 2 +-
>  arch/arm64/crypto/poly1305-core.S_shipped | 2 +-
>  2 files changed, 2 insertions(+), 2 deletions(-)

This needs to be fixed at https://github.com/dot-asm/cryptogams too, I assume?

- Eric

  reply	other threads:[~2020-10-26 23:03 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-10-26 23:00 [PATCH] crypto: arm64/poly1305-neon - reorder PAC authentication with SP update Ard Biesheuvel
2020-10-26 23:03 ` Eric Biggers [this message]
2020-10-26 23:04   ` Ard Biesheuvel
2020-10-26 23:06     ` Ard Biesheuvel
2020-10-29 13:27       ` Andy Polyakov
2020-11-06  7:01 ` Herbert Xu

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