[PATCH 23/49] sctp: pass a kernel pointer to sctp_setsockopt_maxburst

[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 | 35 ++++++++++++++++-------------------
 1 file changed, 16 insertions(+), 19 deletions(-)

diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index 249a87014e879..e62e8dbe961ec 100644
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -3479,12 +3479,13 @@ static int 
sctp_setsockopt_partial_delivery_point(struct sock *sk, u32 *val,
  * future associations inheriting the socket value.
  */
 static int sctp_setsockopt_maxburst(struct sock *sk,
-                                   char __user *optval,
+                                   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;
+       u32 assoc_value;
 
        if (optlen == sizeof(int)) {
                pr_warn_ratelimited(DEPRECATED
@@ -3492,37 +3493,33 @@ static int sctp_setsockopt_maxburst(struct sock *sk,
                                    "Use of int in max_burst socket option 
deprecated.\n"
                                    "Use struct sctp_assoc_value instead\n",
                                    current->comm, task_pid_nr(current));
-               if (copy_from_user(&params.assoc_value, optval, optlen))
-                       return -EFAULT;
-               params.assoc_id = SCTP_FUTURE_ASSOC;
+               assoc_id = SCTP_FUTURE_ASSOC;
+               assoc_value = *((int *)params);
        } else if (optlen == sizeof(struct sctp_assoc_value)) {
-               if (copy_from_user(&params, optval, optlen))
-                       return -EFAULT;
+               assoc_id = params->assoc_id;
+               assoc_value = params->assoc_value;
        } else
                return -EINVAL;
 
-       asoc = sctp_id2assoc(sk, params.assoc_id);
-       if (!asoc && params.assoc_id > SCTP_ALL_ASSOC &&
-           sctp_style(sk, UDP))
+       asoc = sctp_id2assoc(sk, assoc_id);
+       if (!asoc && assoc_id > SCTP_ALL_ASSOC && sctp_style(sk, UDP))
                return -EINVAL;
 
        if (asoc) {
-               asoc->max_burst = params.assoc_value;
+               asoc->max_burst = assoc_value;
 
                return 0;
        }
 
        if (sctp_style(sk, TCP))
-               params.assoc_id = SCTP_FUTURE_ASSOC;
+               assoc_id = SCTP_FUTURE_ASSOC;
 
-       if (params.assoc_id == SCTP_FUTURE_ASSOC ||
-           params.assoc_id == SCTP_ALL_ASSOC)
-               sp->max_burst = params.assoc_value;
+       if (assoc_id == SCTP_FUTURE_ASSOC || assoc_id == SCTP_ALL_ASSOC)
+               sp->max_burst = assoc_value;
 
-       if (params.assoc_id == SCTP_CURRENT_ASSOC ||
-           params.assoc_id == SCTP_ALL_ASSOC)
+       if (assoc_id == SCTP_CURRENT_ASSOC || assoc_id == SCTP_ALL_ASSOC)
                list_for_each_entry(asoc, &sp->ep->asocs, asocs)
-                       asoc->max_burst = params.assoc_value;
+                       asoc->max_burst = assoc_value;
 
        return 0;
 }
@@ -4696,7 +4693,7 @@ static int sctp_setsockopt(struct sock *sk, int level, 
int optname,
                retval = sctp_setsockopt_fragment_interleave(sk, kopt, optlen);
                break;
        case SCTP_MAX_BURST:
-               retval = sctp_setsockopt_maxburst(sk, optval, optlen);
+               retval = sctp_setsockopt_maxburst(sk, kopt, optlen);
                break;
        case SCTP_AUTH_CHUNK:
                retval = sctp_setsockopt_auth_chunk(sk, optval, optlen);
-- 
2.26.2