[Qemu-devel] [PATCH] qcow2: Correct endianness in overlap check

[Max Reitz]

If an inactive L1 table is loaded from disk, its entries are in big
endian and have to be converted to host byte order before using them.

Signed-off-by: Max Reitz <address@hidden>
---
 block/qcow2-refcount.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/block/qcow2-refcount.c b/block/qcow2-refcount.c
index d2b7064..364eeba 100644
--- a/block/qcow2-refcount.c
+++ b/block/qcow2-refcount.c
@@ -1733,8 +1733,8 @@ int qcow2_check_metadata_overlap(BlockDriverState *bs, 
int chk, int64_t offset,
             }
 
             for (j = 0; j < l1_sz; j++) {
-                if ((l1[j] & L1E_OFFSET_MASK) &&
-                    overlaps_with(l1[j] & L1E_OFFSET_MASK, s->cluster_size)) {
+                uint64_t l2_ofs = be64_to_cpu(l1[j]) & L1E_OFFSET_MASK;
+                if (l2_ofs && overlaps_with(l2_ofs, s->cluster_size)) {
                     g_free(l1);
                     return QCOW2_OL_INACTIVE_L2;
                 }
-- 
1.8.3.1