[PATCH 24/49] sctp: pass a kernel pointer to sctp_setsockopt_auth_chunk

[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 | 11 ++++-------
 1 file changed, 4 insertions(+), 7 deletions(-)

diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index e62e8dbe961ec..aa06affcd66e0 100644
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -3532,21 +3532,18 @@ static int sctp_setsockopt_maxburst(struct sock *sk,
  * will only effect future associations on the socket.
  */
 static int sctp_setsockopt_auth_chunk(struct sock *sk,
-                                     char __user *optval,
+                                     struct sctp_authchunk *val,
                                      unsigned int optlen)
 {
        struct sctp_endpoint *ep = sctp_sk(sk)->ep;
-       struct sctp_authchunk val;
 
        if (!ep->auth_enable)
                return -EACCES;
 
        if (optlen != sizeof(struct sctp_authchunk))
                return -EINVAL;
-       if (copy_from_user(&val, optval, optlen))
-               return -EFAULT;
 
-       switch (val.sauth_chunk) {
+       switch (val->sauth_chunk) {
        case SCTP_CID_INIT:
        case SCTP_CID_INIT_ACK:
        case SCTP_CID_SHUTDOWN_COMPLETE:
@@ -3555,7 +3552,7 @@ static int sctp_setsockopt_auth_chunk(struct sock *sk,
        }
 
        /* add this chunk id to the endpoint */
-       return sctp_auth_ep_add_chunkid(ep, val.sauth_chunk);
+       return sctp_auth_ep_add_chunkid(ep, val->sauth_chunk);
 }
 
 /*
@@ -4696,7 +4693,7 @@ static int sctp_setsockopt(struct sock *sk, int level, 
int optname,
                retval = sctp_setsockopt_maxburst(sk, kopt, optlen);
                break;
        case SCTP_AUTH_CHUNK:
-               retval = sctp_setsockopt_auth_chunk(sk, optval, optlen);
+               retval = sctp_setsockopt_auth_chunk(sk, kopt, optlen);
                break;
        case SCTP_HMAC_IDENT:
                retval = sctp_setsockopt_hmac_ident(sk, optval, optlen);
-- 
2.26.2