xen/gntdev: don't leak memory from IOCTL_GNTDEV_MAP_GRANT_REF

map->kmap_ops allocated in gntdev_alloc_map() wasn't freed by
gntdev_put_map().

Add a gntdev_free_map() helper function to free everything allocated
by gntdev_alloc_map().

Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Cc: stable@vger.kernel.org
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

1 files changed, 19 insertions, 17 deletions

diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c
index 610bfc6be177..2e22df2f7a3f 100644
--- a/drivers/xen/gntdev.c
+++ b/drivers/xen/gntdev.c
@@ -105,6 +105,21 @@ static void gntdev_print_maps(struct gntdev_priv *priv,
 #endif
 }
 
+static void gntdev_free_map(struct grant_map *map)
+{
+        if (map == NULL)
+                return;
+
+        if (map->pages)
+                free_xenballooned_pages(map->count, map->pages);
+        kfree(map->pages);
+        kfree(map->grants);
+        kfree(map->map_ops);
+        kfree(map->unmap_ops);
+        kfree(map->kmap_ops);
+        kfree(map);
+}
+
 static struct grant_map *gntdev_alloc_map(struct gntdev_priv *priv, int count)
 {
         struct grant_map *add;
@@ -142,12 +157,7 @@ static struct grant_map *gntdev_alloc_map(struct gntdev_priv *priv, int count)
         return add;
 
 err:
-        kfree(add->pages);
-        kfree(add->grants);
-        kfree(add->map_ops);
-        kfree(add->unmap_ops);
-        kfree(add->kmap_ops);
-        kfree(add);
+        gntdev_free_map(add);
         return NULL;
 }
 
@@ -198,17 +208,9 @@ static void gntdev_put_map(struct grant_map *map)
                 evtchn_put(map->notify.event);
         }
 
-        if (map->pages) {
-                if (!use_ptemod)
-                        unmap_grant_pages(map, 0, map->count);
-
-                free_xenballooned_pages(map->count, map->pages);
-        }
-        kfree(map->pages);
-        kfree(map->grants);
-        kfree(map->map_ops);
-        kfree(map->unmap_ops);
-        kfree(map);
+        if (map->pages && !use_ptemod)
+                unmap_grant_pages(map, 0, map->count);
+        gntdev_free_map(map);
 }
 
 /* ------------------------------------------------------------------ */