[Qemu-devel] [PULL 24/32] qcow2: Avoid making the L1 table too big

[Kevin Wolf]

From: Max Reitz <address@hidden>

We refuse to open images whose L1 table we deem "too big". Consequently,
we should not produce such images ourselves.

Cc: address@hidden
Signed-off-by: Max Reitz <address@hidden>
Message-id: address@hidden
Reviewed-by: Eric Blake <address@hidden>
[mreitz: Added QEMU_BUILD_BUG_ON()]
Signed-off-by: Max Reitz <address@hidden>
---
 block/qcow2-cluster.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c
index 6b92ce9..00c16dc 100644
--- a/block/qcow2-cluster.c
+++ b/block/qcow2-cluster.c
@@ -65,7 +65,8 @@ int qcow2_grow_l1_table(BlockDriverState *bs, uint64_t 
min_size,
         }
     }
 
-    if (new_l1_size > INT_MAX / sizeof(uint64_t)) {
+    QEMU_BUILD_BUG_ON(QCOW_MAX_L1_SIZE > INT_MAX);
+    if (new_l1_size > QCOW_MAX_L1_SIZE / sizeof(uint64_t)) {
         return -EFBIG;
     }
 
-- 
1.8.3.1