sctp: pass a kernel pointer to sctp_setsockopt_auth_key

Use the kernel pointer that sctp_setsockopt has available instead of
directly handling the user pointer.  Adapt sctp_setsockopt to use a
kzfree for this case.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index 3651457..b4dcccb 100644 (file)
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -3594,11 +3594,10 @@ static int sctp_setsockopt_hmac_ident(struct sock *sk,
  * association shared key.
  */
 static int sctp_setsockopt_auth_key(struct sock *sk,
-                                   char __user *optval,
+                                   struct sctp_authkey *authkey,
                                    unsigned int optlen)
 {
        struct sctp_endpoint *ep = sctp_sk(sk)->ep;
-       struct sctp_authkey *authkey;
        struct sctp_association *asoc;
        int ret = -EINVAL;
 
@@ -3609,10 +3608,6 @@ static int sctp_setsockopt_auth_key(struct sock *sk,
         */
        optlen = min_t(unsigned int, optlen, USHRT_MAX + sizeof(*authkey));
 
-       authkey = memdup_user(optval, optlen);
-       if (IS_ERR(authkey))
-               return PTR_ERR(authkey);
-
        if (authkey->sca_keylength > optlen - sizeof(*authkey))
                goto out;
 
@@ -3650,7 +3645,6 @@ static int sctp_setsockopt_auth_key(struct sock *sk,
 
 out:
        memzero_explicit(authkey, optlen);
-       kfree(authkey);
        return ret;
 }
 
@@ -4692,7 +4686,7 @@ static int sctp_setsockopt(struct sock *sk, int level, int optname,
                retval = sctp_setsockopt_hmac_ident(sk, kopt, optlen);
                break;
        case SCTP_AUTH_KEY:
-               retval = sctp_setsockopt_auth_key(sk, optval, optlen);
+               retval = sctp_setsockopt_auth_key(sk, kopt, optlen);
                break;
        case SCTP_AUTH_ACTIVE_KEY:
                retval = sctp_setsockopt_active_key(sk, optval, optlen);