block/dmg: validate chunk size to avoid overflow

Previously the chunk size was not checked, allowing for a large memory
allocation. This patch checks whether the chunks size is within the
resource fork length.

Signed-off-by: Peter Wu <peter@lekensteyn.nl>

1 files changed, 1 insertions, 1 deletions

diff --git a/block/dmg.c b/block/dmg.c
index 75e771af40..19e4fe2b19 100644
--- a/block/dmg.c
+++ b/block/dmg.c
@@ -308,7 +308,7 @@ static int dmg_read_resource_fork(BlockDriverState *bs, DmgHeaderState *ds,
         ret = read_uint32(bs, offset, &count);
         if (ret < 0) {
             goto fail;
-        } else if (count == 0) {
+        } else if (count == 0 || count > info_end - offset) {
             ret = -EINVAL;
             goto fail;
         }