[Qemu-devel] [PATCH 1/2] qcow2: Fix refcount table size calculation

[Kevin Wolf <kwolf@redhat.com>]

A missing factor for the refcount table entry size in the calculation
could mean that too little memory was allocated for the in-memory
representation of the table, resulting in a buffer overflow.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block/qcow2-refcount.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/block/qcow2-refcount.c b/block/qcow2-refcount.c
index 5e3f915..96224d1 100644
--- a/block/qcow2-refcount.c
+++ b/block/qcow2-refcount.c
@@ -301,7 +301,8 @@ static int alloc_refcount_block(BlockDriverState *bs,
     uint64_t last_table_size;
     uint64_t blocks_clusters;
     do {
-        uint64_t table_clusters = size_to_clusters(s, table_size);
+        uint64_t table_clusters =
+            size_to_clusters(s, table_size * sizeof(uint64_t));
         blocks_clusters = 1 +
             ((table_clusters + refcount_block_clusters - 1)
             / refcount_block_clusters);
-- 
1.7.6.5