The current AF_ALG implementation requires that a userspace interface
implementation must provide a callback for setkey. Such a call is not
appliable to random number generators.

To prepare AF_ALG for the addition of a random number generator user
space interface, this function callback invocation is made optional.

Signed-off-by: Stephan Mueller <redacted>
---
 crypto/af_alg.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/crypto/af_alg.c b/crypto/af_alg.c
index 635140b..47a199c 100644
--- a/crypto/af_alg.c
+++ b/crypto/af_alg.c

@@ -177,6 +177,9 @@ static int alg_setkey(struct sock *sk, char __user *ukey,
 	u8 *key;
 	int err;
 
+	if (!type->setkey)
+		return -EOPNOTSUPP;
+
 	key = sock_kmalloc(sk, keylen, GFP_KERNEL);
 	if (!key)
 		return -ENOMEM;

-- 
2.1.0