svc: check for allocation overflow in crypto calls part 2

Without checking for overflow there is a risk of allocating a buffer
with size smaller than anticipated and as a consequence of that it might
lead to a heap based overflow with attacker controlled data written
outside the boundaries of the buffer.

Fixes: OP-TEE-2018-0011: "Integer overflow in crypto system calls (x2)"

Signed-off-by: Joakim Bech <joakim.bech@linaro.org>
Tested-by: Joakim Bech <joakim.bech@linaro.org> (QEMU v7, v8)
Reviewed-by: Jens Wiklander <jens.wiklander@linaro.org>
Reported-by: Riscure <inforequest@riscure.com>
Reported-by: Alyssa Milburn <a.a.milburn@vu.nl>
Acked-by: Etienne Carriere <etienne.carriere@linaro.org>
TEE_Result syscall_cipher_update(unsigned long state, const void *src,
			size_t src_len, void *dst, uint64_t *dst_len)
{
	return tee_svc_cipher_update_helper(state, false /* last_block */,
					    src, src_len, dst, dst_len);
}

TEE_Result syscall_cipher_update(unsigned long state, const void *src,
			size_t src_len, void *dst, uint64_t *dst_len)
{
	return tee_svc_cipher_update_helper(state, false /* last_block */,
					    src, src_len, dst, dst_len);
}
