xen/privcmd: return -EFAULT on error

__copy_to_user() returns the number of bytes remaining to be copied but
we want to return a negative error code here.

Acked-by: Andres Lagar-Cavilla <andres@lagarcavilla.org>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

1 files changed, 4 insertions, 1 deletions

diff --git a/drivers/xen/privcmd.c b/drivers/xen/privcmd.c
index 3b162c656205..ef6389580b8c 100644
--- a/drivers/xen/privcmd.c
+++ b/drivers/xen/privcmd.c
@@ -389,8 +389,11 @@ static long privcmd_ioctl_mmap_batch(void __user *udata, int version)
                 state.err      = err_array;
                 ret = traverse_pages(m.num, sizeof(xen_pfn_t),
                                      &pagelist, mmap_return_errors_v1, &state);
-        } else if (version == 2)
+        } else if (version == 2) {
                 ret = __copy_to_user(m.err, err_array, m.num * sizeof(int));
+                if (ret)
+                        ret = -EFAULT;
+        }
 
         /* If we have not had any EFAULT-like global errors then set the global
          * error to -ENOENT if necessary. */