staging: comedi: check return code of put_user

Function put_user may fail. Check for it.

Signed-off-by: Vasiliy Kulikov <segooon@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 2 insertions, 1 deletions

diff --git a/drivers/staging/comedi/comedi_fops.c b/drivers/staging/comedi/comedi_fops.c
index 14091313ceb..98fa255d862 100644
--- a/drivers/staging/comedi/comedi_fops.c
+++ b/drivers/staging/comedi/comedi_fops.c
@@ -537,7 +537,8 @@ static int do_chaninfo_ioctl(struct comedi_device *dev,
 
                         x = (dev->minor << 28) | (it.subdev << 24) | (i << 16) |
                             (s->range_table_list[i]->length);
-                        put_user(x, it.rangelist + i);
+                        if (put_user(x, it.rangelist + i))
+                                return -EFAULT;
                 }
 #if 0
                 if (copy_to_user(it.rangelist, s->range_type_list,