[Qemu-devel] [PATCH v2 09/12] qcow2/overlaps: Protect snapshot table

[Max Reitz <mreitz@redhat.com>]

Keep track of the snapshot table in the metadata list to protect it
against accidental modifications.

Signed-off-by: Max Reitz <mreitz@redhat.com>
---
 block/qcow2-snapshot.c | 10 ++++++++++
 block/qcow2.c          |  6 ++++++
 2 files changed, 16 insertions(+)

diff --git a/block/qcow2-snapshot.c b/block/qcow2-snapshot.c
index d83a939..c32d889 100644
--- a/block/qcow2-snapshot.c
+++ b/block/qcow2-snapshot.c
@@ -262,8 +262,18 @@ static int qcow2_write_snapshots(BlockDriverState *bs)
     /* free the old snapshot table */
     qcow2_free_clusters(bs, s->snapshots_offset, s->snapshots_size,
                         QCOW2_DISCARD_SNAPSHOT);
+
+    qcow2_metadata_list_remove(bs, s->snapshots_offset,
+                               size_to_clusters(s, s->snapshots_size),
+                               QCOW2_OL_SNAPSHOT_TABLE);
+
     s->snapshots_offset = snapshots_offset;
     s->snapshots_size = snapshots_size;
+
+    qcow2_metadata_list_enter(bs, s->snapshots_offset,
+                              size_to_clusters(s, s->snapshots_size),
+                              QCOW2_OL_SNAPSHOT_TABLE);
+
     return 0;
 
 fail:
diff --git a/block/qcow2.c b/block/qcow2.c
index d0950fc..468090d 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -798,6 +798,12 @@ static int qcow2_open(BlockDriverState *bs, QDict *options, int flags,
         error_setg(errp, "Invalid snapshot table offset");
         goto fail;
     }
+    if (header.nb_snapshots) {
+        qcow2_metadata_list_enter(bs, header.snapshots_offset,
+                                  size_to_clusters(s, header.nb_snapshots *
+                                                   sizeof(QCowSnapshotHeader)),
+                                  QCOW2_OL_SNAPSHOT_TABLE);
+    }
 
     /* read the level 1 table */
     if (header.l1_size > QCOW_MAX_L1_SIZE) {
-- 
1.9.3