From: Elena Petrova <lenaptr@xxxxxxxxxx> commit 6bd934de1e393466b319d29c4427598fda096c57 upstream. The sha256-ce finup implementation for ARM64 produces wrong digest for empty input (len=0). Expected: the actual digest, result: initial value of SHA internal state. The error is in sha256_ce_finup: for empty data `finalize` will be 1, so the code is relying on sha2_ce_transform to make the final round. However, in sha256_base_do_update, the block function will not be called when len == 0. Fix it by setting finalize to 0 if data is empty. Fixes: 03802f6a80b3a ("crypto: arm64/sha2-ce - move SHA-224/256 ARMv8 implementation to base layer") Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Elena Petrova <lenaptr@xxxxxxxxxx> Reviewed-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx> Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/arm64/crypto/sha2-ce-glue.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/arch/arm64/crypto/sha2-ce-glue.c +++ b/arch/arm64/crypto/sha2-ce-glue.c @@ -59,7 +59,7 @@ static int sha256_ce_finup(struct shash_ unsigned int len, u8 *out) { struct sha256_ce_state *sctx = shash_desc_ctx(desc); - bool finalize = !sctx->sst.count && !(len % SHA256_BLOCK_SIZE); + bool finalize = !sctx->sst.count && !(len % SHA256_BLOCK_SIZE) && len; if (!may_use_simd()) { if (len)