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>

1 files changed, 2 insertions, 1 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);