1 files changed, 1 insertions, 1 deletions

diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c
index 0956b8659360..ddda8107aa7e 100644
--- a/drivers/md/dm-ioctl.c
+++ b/drivers/md/dm-ioctl.c
@@ -1840,7 +1840,7 @@ static int ctl_ioctl(uint command, struct dm_ioctl __user *user)
         if (r)
                 goto out;
 
-        param->data_size = sizeof(*param);
+        param->data_size = offsetof(struct dm_ioctl, data);
         r = fn(param, input_param_size);
 
         if (unlikely(param->flags & DM_BUFFER_FULL_FLAG) &&