sctp: pass a kernel pointer to sctp_setsockopt_maxseg

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

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 5007af3..cc7d543 100644 (file)
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -3215,11 +3215,13 @@ static int sctp_setsockopt_mappedv4(struct sock *sk, int *val,
  *    changed (effecting future associations only).
  * assoc_value:  This parameter specifies the maximum size in bytes.
  */
-static int sctp_setsockopt_maxseg(struct sock *sk, char __user *optval, unsigned int optlen)
+static int sctp_setsockopt_maxseg(struct sock *sk,
+                                 struct sctp_assoc_value *params,
+                                 unsigned int optlen)
 {
        struct sctp_sock *sp = sctp_sk(sk);
-       struct sctp_assoc_value params;
        struct sctp_association *asoc;
+       sctp_assoc_t assoc_id;
        int val;
 
        if (optlen == sizeof(int)) {
@@ -3228,19 +3230,17 @@ static int sctp_setsockopt_maxseg(struct sock *sk, char __user *optval, unsigned
                                    "Use of int in maxseg socket option.\n"
                                    "Use struct sctp_assoc_value instead\n",
                                    current->comm, task_pid_nr(current));
-               if (copy_from_user(&val, optval, optlen))
-                       return -EFAULT;
-               params.assoc_id = SCTP_FUTURE_ASSOC;
+               assoc_id = SCTP_FUTURE_ASSOC;
+               val = *(int *)params;
        } else if (optlen == sizeof(struct sctp_assoc_value)) {
-               if (copy_from_user(&params, optval, optlen))
-                       return -EFAULT;
-               val = params.assoc_value;
+               assoc_id = params->assoc_id;
+               val = params->assoc_value;
        } else {
                return -EINVAL;
        }
 
-       asoc = sctp_id2assoc(sk, params.assoc_id);
-       if (!asoc && params.assoc_id != SCTP_FUTURE_ASSOC &&
+       asoc = sctp_id2assoc(sk, assoc_id);
+       if (!asoc && assoc_id != SCTP_FUTURE_ASSOC &&
            sctp_style(sk, UDP))
                return -EINVAL;
 
@@ -4697,7 +4697,7 @@ static int sctp_setsockopt(struct sock *sk, int level, int optname,
                retval = sctp_setsockopt_mappedv4(sk, kopt, optlen);
                break;
        case SCTP_MAXSEG:
-               retval = sctp_setsockopt_maxseg(sk, optval, optlen);
+               retval = sctp_setsockopt_maxseg(sk, kopt, optlen);
                break;
        case SCTP_ADAPTATION_LAYER:
                retval = sctp_setsockopt_adaptation_layer(sk, optval, optlen);