(EC)DSA signature without hashing, or with offloaded hash?
Let's focus on DSA. The signing on a message $m\in \mathbb{Z}_q$ for the suggested "no-hash" protocol is done as follows: 


Pick $k\in_R \mathbb{Z}_q$, compute $r=f(g^k)$, where $f(\cdot):=(\cdot \bmod p) \bmod q$.
Compute $s=k^{-1}(m+xr)\bmod q$
Return $(r,s)$ if the signature is not degenerate.


The verification algorithm, on input $(m,s,r)$, checks if $f((g^m\cdot y^r)^{(1/s)})=r$.

The following consists of a forgery on a random message under the key-only attack.


Let $K=g^a\cdot y^b$, where $a,b\in_R\mathbb{Z}_q$
Compute $r=f(K)$, and set $s=r/b$
Return $(r,s)$ as a forgery on $m=(a\cdot r)/b$


(I'll add the references in due course.)