crypto: af_alg - Fix regression on empty requests

Some user-space programs rely on crypto requests that have no
control metadata.  This broke when a check was added to require
the presence of control metadata with the ctx->init flag.

This patch fixes the regression by setting ctx->init as long as
one sendmsg(2) has been made, with or without a control message.

Reported-by: Sachin Sant <sachinp@linux.vnet.ibm.com>
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Fixes: f3c802a1f3 ("crypto: algif_aead - Only wake up when...")
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto/af_alg.c

@@ -851,6 +851,7 @@ int af_alg_sendmsg(struct socket *sock, struct msghdr *msg, size_t size,
 		err = -EINVAL;
 		goto unlock;
 	}
+	ctx->init = true;
 
 	if (init) {
 		ctx->enc = enc;
@@ -858,7 +859,6 @@ int af_alg_sendmsg(struct socket *sock, struct msghdr *msg, size_t size,
 			memcpy(ctx->iv, con.iv->iv, ivsize);
 
 		ctx->aead_assoclen = con.aead_assoclen;
-		ctx->init = true;
 	}
 
 	while (size) {