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References: <20230227063223.1829703-1-ebiggers@kernel.org>
In-Reply-To: <20230227063223.1829703-1-ebiggers@kernel.org>
From:   Ard Biesheuvel <ardb@kernel.org>
Date:   Mon, 27 Feb 2023 08:59:04 +0100
Message-ID: <CAMj1kXFbUuH1_vp=+sAFDorFSaFFUsaLjzjHFPbv_OZ_VAPK=w@mail.gmail.com>
Subject: Re: [PATCH] crypto: arm64/aes-neonbs - fix crash with CFI enabled
To:     Eric Biggers <ebiggers@kernel.org>
Cc:     linux-crypto@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        Sami Tolvanen <samitolvanen@google.com>, stable@vger.kernel.org
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On Mon, 27 Feb 2023 at 07:33, Eric Biggers <ebiggers@kernel.org> wrote:
>
> From: Eric Biggers <ebiggers@google.com>
>
> aesbs_ecb_encrypt(), aesbs_ecb_decrypt(), aesbs_xts_encrypt(), and
> aesbs_xts_decrypt() are called via indirect function calls.  Therefore
> they need to use SYM_TYPED_FUNC_START instead of SYM_FUNC_START to cause
> their type hashes to be emitted when the kernel is built with
> CONFIG_CFI_CLANG=y.  Otherwise, the code crashes with a CFI failure if
> the compiler doesn't happen to optimize out the indirect calls.
>
> Fixes: c50d32859e70 ("arm64: Add types to indirect called assembly functions")
> Cc: stable@vger.kernel.org
> Signed-off-by: Eric Biggers <ebiggers@google.com>

Reviewed-by: Ard Biesheuvel <ardb@kernel.org>

> ---
>  arch/arm64/crypto/aes-neonbs-core.S | 9 +++++----
>  1 file changed, 5 insertions(+), 4 deletions(-)
>
> diff --git a/arch/arm64/crypto/aes-neonbs-core.S b/arch/arm64/crypto/aes-neonbs-core.S
> index 7278a37c2d5c..baf450717b24 100644
> --- a/arch/arm64/crypto/aes-neonbs-core.S
> +++ b/arch/arm64/crypto/aes-neonbs-core.S
> @@ -15,6 +15,7 @@
>   */
>
>  #include <linux/linkage.h>
> +#include <linux/cfi_types.h>
>  #include <asm/assembler.h>
>
>         .text
> @@ -620,12 +621,12 @@ SYM_FUNC_END(aesbs_decrypt8)
>         .endm
>
>         .align          4
> -SYM_FUNC_START(aesbs_ecb_encrypt)
> +SYM_TYPED_FUNC_START(aesbs_ecb_encrypt)
>         __ecb_crypt     aesbs_encrypt8, v0, v1, v4, v6, v3, v7, v2, v5
>  SYM_FUNC_END(aesbs_ecb_encrypt)
>
>         .align          4
> -SYM_FUNC_START(aesbs_ecb_decrypt)
> +SYM_TYPED_FUNC_START(aesbs_ecb_decrypt)
>         __ecb_crypt     aesbs_decrypt8, v0, v1, v6, v4, v2, v7, v3, v5
>  SYM_FUNC_END(aesbs_ecb_decrypt)
>
> @@ -799,11 +800,11 @@ SYM_FUNC_END(__xts_crypt8)
>         ret
>         .endm
>
> -SYM_FUNC_START(aesbs_xts_encrypt)
> +SYM_TYPED_FUNC_START(aesbs_xts_encrypt)
>         __xts_crypt     aesbs_encrypt8, v0, v1, v4, v6, v3, v7, v2, v5
>  SYM_FUNC_END(aesbs_xts_encrypt)
>
> -SYM_FUNC_START(aesbs_xts_decrypt)
> +SYM_TYPED_FUNC_START(aesbs_xts_decrypt)
>         __xts_crypt     aesbs_decrypt8, v0, v1, v6, v4, v2, v7, v3, v5
>  SYM_FUNC_END(aesbs_xts_decrypt)
>
>
> base-commit: f3a2439f20d918930cc4ae8f76fe1c1afd26958f
> --
> 2.39.2
>