can: Fix copy_from_user() results interpretation
Both copy_to_ and _from_user return the number of bytes, that failed to
reach their destination, not the 0/-EXXX values.
Based on patch from Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Oliver Hartkopp <oliver.hartkopp@volkswagen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/can/raw.c b/net/can/raw.c
index 201cbfc..69877b8 100644
--- a/net/can/raw.c
+++ b/net/can/raw.c
@@ -435,15 +435,13 @@
if (!filter)
return -ENOMEM;
- err = copy_from_user(filter, optval, optlen);
- if (err) {
+ if (copy_from_user(filter, optval, optlen)) {
kfree(filter);
- return err;
+ return -EFAULT;
}
} else if (count == 1) {
- err = copy_from_user(&sfilter, optval, optlen);
- if (err)
- return err;
+ if (copy_from_user(&sfilter, optval, optlen))
+ return -EFAULT;
}
lock_sock(sk);
@@ -493,9 +491,8 @@
if (optlen != sizeof(err_mask))
return -EINVAL;
- err = copy_from_user(&err_mask, optval, optlen);
- if (err)
- return err;
+ if (copy_from_user(&err_mask, optval, optlen))
+ return -EFAULT;
err_mask &= CAN_ERR_MASK;
@@ -531,7 +528,8 @@
if (optlen != sizeof(ro->loopback))
return -EINVAL;
- err = copy_from_user(&ro->loopback, optval, optlen);
+ if (copy_from_user(&ro->loopback, optval, optlen))
+ return -EFAULT;
break;
@@ -539,7 +537,8 @@
if (optlen != sizeof(ro->recv_own_msgs))
return -EINVAL;
- err = copy_from_user(&ro->recv_own_msgs, optval, optlen);
+ if (copy_from_user(&ro->recv_own_msgs, optval, optlen))
+ return -EFAULT;
break;