1 files changed, 2 insertions, 1 deletions

diff --git a/drivers/isdn/isdnloop/isdnloop.c b/drivers/isdn/isdnloop/isdnloop.c
index 23afba46433e..c3ae2edaf6fa 100644
--- a/drivers/isdn/isdnloop/isdnloop.c
+++ b/drivers/isdn/isdnloop/isdnloop.c
@@ -446,7 +446,8 @@ isdnloop_readstatus(u_char __user *buf, int len, isdnloop_card * card)
         for (p = buf, count = 0; count < len; p++, count++) {
                 if (card->msg_buf_read == card->msg_buf_write)
                         return count;
-                put_user(*card->msg_buf_read++, p);
+                if (put_user(*card->msg_buf_read++, p))
+                        return -EFAULT;
                 if (card->msg_buf_read > card->msg_buf_end)
                         card->msg_buf_read = card->msg_buf;
         }