On Fri, Feb 23, 2024 at 02:20:35PM +0100, Ard Biesheuvel wrote:
> From: Ard Biesheuvel <ardb@xxxxxxxxxx>
>
> The bit-sliced implementation of AES-CTR operates on blocks of 128
> bytes, and will fall back to the plain NEON version for tail blocks or
> inputs that are shorter than 128 bytes to begin with.
>
> It will call straight into the plain NEON asm helper, which performs all
> memory accesses in granules of 16 bytes (the size of a NEON register).
> For this reason, the associated plain NEON glue code will copy inputs
> shorter than 16 bytes into a temporary buffer, given that this is a rare
> occurrence and it is not worth the effort to work around this in the asm
> code.
>
> The fallback from the bit-sliced NEON version fails to take this into
> account, potentially resulting in out-of-bounds accesses. So clone the
> same workaround, and use a temp buffer for short in/outputs.
>
> Fixes: fc074e130051 ("crypto: arm64/aes-neonbs-ctr - fallback to plain NEON for final chunk")
> Reported-by: syzbot+f1ceaa1a09ab891e1934@xxxxxxxxxxxxxxxxxxxxxxxxx
> Reviewed-by: Eric Biggers <ebiggers@xxxxxxxxxx>
> Signed-off-by: Ard Biesheuvel <ardb@xxxxxxxxxx>
> ---
> arch/arm64/crypto/aes-neonbs-glue.c | 11 +++++++++++
> 1 file changed, 11 insertions(+)
Patch applied. Thanks.
--
Email: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
