[PATCH 027/241] xen/gntdev: don't leak memory from IOCTL_GNTDEV_MAP_GRANT_REF

From: Herton Ronaldo Krzesinski
Date: Thu Dec 13 2012 - 10:06:39 EST


3.5.7.2 -stable review patch. If anyone has any objections, please let me know.

------------------

From: David Vrabel <david.vrabel@xxxxxxxxxx>

commit a67baeb77375199bbd842fa308cb565164dd1f19 upstream.

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@xxxxxxxxxx>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski@xxxxxxxxxxxxx>
---
drivers/xen/gntdev.c | 36 +++++++++++++++++++-----------------
1 file changed, 19 insertions(+), 17 deletions(-)

diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c
index 7f12416..9a113b7 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);
}

/* ------------------------------------------------------------------ */
--
1.7.9.5

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