net: Fix wrong interpretation of some copy_to_user() results.

I found some places, that erroneously return the value obtained from
the copy_to_user() call: if some amount of bytes were not able to get
to the user (this is what this one returns) the proper behavior is to
return the -EFAULT error, not that number itself.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 5 insertions, 4 deletions

diff --git a/net/can/raw.c b/net/can/raw.c
index ead50c7c0d40..201cbfc6b9ec 100644
--- a/net/can/raw.c
+++ b/net/can/raw.c
@@ -573,7 +573,8 @@ static int raw_getsockopt(struct socket *sock, int level, int optname,
                         int fsize = ro->count * sizeof(struct can_filter);
                         if (len > fsize)
                                 len = fsize;
-                        err = copy_to_user(optval, ro->filter, len);
+                        if (copy_to_user(optval, ro->filter, len))
+                                err = -EFAULT;
                 } else
                         len = 0;
                 release_sock(sk);
diff --git a/net/dccp/probe.c b/net/dccp/probe.c
index 6e1df62bd7c9..0bcdc9250279 100644
--- a/net/dccp/probe.c
+++ b/net/dccp/probe.c
@@ -140,7 +140,7 @@ static ssize_t dccpprobe_read(struct file *file, char __user *buf,
                 goto out_free;
 
         cnt = kfifo_get(dccpw.fifo, tbuf, len);
-        error = copy_to_user(buf, tbuf, cnt);
+        error = copy_to_user(buf, tbuf, cnt) ? -EFAULT : 0;
 
 out_free:
         vfree(tbuf);
diff --git a/net/tipc/socket.c b/net/tipc/socket.c
index 05853159536a..230f9ca2ad6b 100644
--- a/net/tipc/socket.c
+++ b/net/tipc/socket.c
@@ -1756,8 +1756,8 @@ static int getsockopt(struct socket *sock,
         else if (len < sizeof(value)) {
                 res = -EINVAL;
         }
-        else if ((res = copy_to_user(ov, &value, sizeof(value)))) {
-                /* couldn't return value */
+        else if (copy_to_user(ov, &value, sizeof(value))) {
+                res = -EFAULT;
         }
         else {
                 res = put_user(sizeof(value), ol);