On Tue, Jul 12, 2022 at 03:50:31PM +0800, GUO Zihua wrote:
> A kasan error was reported during fuzzing:
[...]
> This patch fixes the issue by calling poly1305_init_arm64() instead of
> poly1305_init_arch(). This is also the implementation for the same
> algorithm on arm platform.
>
> Fixes: f569ca164751 ("crypto: arm64/poly1305 - incorporate OpenSSL/CRYPTOGAMS NEON implementation")
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: GUO Zihua <guozihua@xxxxxxxxxx>
> ---
> arch/arm64/crypto/poly1305-glue.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
I'm not a crypto guy by any stretch of the imagination, but Ard is out
at the moment and this looks like an important fix so I had a crack at
reviewing it.
> diff --git a/arch/arm64/crypto/poly1305-glue.c b/arch/arm64/crypto/poly1305-glue.c
> index 9c3d86e397bf..1fae18ba11ed 100644
> --- a/arch/arm64/crypto/poly1305-glue.c
> +++ b/arch/arm64/crypto/poly1305-glue.c
> @@ -52,7 +52,7 @@ static void neon_poly1305_blocks(struct poly1305_desc_ctx *dctx, const u8 *src,
> {
> if (unlikely(!dctx->sset)) {
> if (!dctx->rset) {
> - poly1305_init_arch(dctx, src);
> + poly1305_init_arm64(&dctx->h, src);
> src += POLY1305_BLOCK_SIZE;
> len -= POLY1305_BLOCK_SIZE;
> dctx->rset = 1;
With this change, we no longer initialise dctx->buflen to 0 as part of the
initialisation. Looking at neon_poly1305_do_update(), I'm a bit worried
that we could land in the 'if (likely(len >= POLY1305_BLOCK_SIZE))' block,
end up with len == 0 and fail to set dctx->buflen. Is this a problem, or is
my ignorance showing?
Will
