[PATCH 47/49] sctp: pass a kernel pointer to sctp_setsockopt_auth_supported

[Christoph Hellwig]

Use the kernel pointer that sctp_setsockopt has available instead of
directly handling the user pointer.

Signed-off-by: Christoph Hellwig <h...@lst.de>
---
 net/sctp/socket.c | 20 +++++++-------------
 1 file changed, 7 insertions(+), 13 deletions(-)

diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index 0aa7265c9c9a0..755bb23ffa3c9 100644
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -4322,29 +4322,23 @@ static int sctp_setsockopt_asconf_supported(struct sock 
*sk,
 }
 
 static int sctp_setsockopt_auth_supported(struct sock *sk,
-                                         char __user *optval,
+                                         struct sctp_assoc_value *params,
                                          unsigned int optlen)
 {
-       struct sctp_assoc_value params;
        struct sctp_association *asoc;
        struct sctp_endpoint *ep;
        int retval = -EINVAL;
 
-       if (optlen != sizeof(params))
-               goto out;
-
-       if (copy_from_user(&params, optval, optlen)) {
-               retval = -EFAULT;
+       if (optlen != sizeof(*params))
                goto out;
-       }
 
-       asoc = sctp_id2assoc(sk, params.assoc_id);
-       if (!asoc && params.assoc_id != SCTP_FUTURE_ASSOC &&
+       asoc = sctp_id2assoc(sk, params->assoc_id);
+       if (!asoc && params->assoc_id != SCTP_FUTURE_ASSOC &&
            sctp_style(sk, UDP))
                goto out;
 
        ep = sctp_sk(sk)->ep;
-       if (params.assoc_value) {
+       if (params->assoc_value) {
                retval = sctp_auth_init(ep, GFP_KERNEL);
                if (retval)
                        goto out;
@@ -4354,7 +4348,7 @@ static int sctp_setsockopt_auth_supported(struct sock *sk,
                }
        }
 
-       ep->auth_enable = !!params.assoc_value;
+       ep->auth_enable = !!params->assoc_value;
        retval = 0;
 
 out:
@@ -4634,7 +4628,7 @@ static int sctp_setsockopt(struct sock *sk, int level, 
int optname,
                retval = sctp_setsockopt_asconf_supported(sk, kopt, optlen);
                break;
        case SCTP_AUTH_SUPPORTED:
-               retval = sctp_setsockopt_auth_supported(sk, optval, optlen);
+               retval = sctp_setsockopt_auth_supported(sk, kopt, optlen);
                break;
        case SCTP_ECN_SUPPORTED:
                retval = sctp_setsockopt_ecn_supported(sk, optval, optlen);
-- 
2.26.2