qcow2: Read outside array bounds in qcow2_pre_write_overlap_check()
The commit for 0e4e4318eaa5 increments QCOW2_OL_MAX_BITNR but does not
add an array entry for QCOW2_OL_BITMAP_DIRECTORY_BITNR to metadata_ol_names[].
As a result, an array dereference of metadata_ol_names[8] in
qcow2_pre_write_overlap_check() could result in a read outside of the array bounds.
Fixes: 0e4e4318eaa5 ('qcow2: add overlap check for bitmap directory')
Cc: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Liam Merwick <Liam.Merwick@oracle.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 1541453919-25973-6-git-send-email-Liam.Merwick@oracle.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
diff --git a/block/qcow2-refcount.c b/block/qcow2-refcount.c
index 3c539f0..46082ae 100644
--- a/block/qcow2-refcount.c
+++ b/block/qcow2-refcount.c
@@ -2719,15 +2719,17 @@
}
static const char *metadata_ol_names[] = {
- [QCOW2_OL_MAIN_HEADER_BITNR] = "qcow2_header",
- [QCOW2_OL_ACTIVE_L1_BITNR] = "active L1 table",
- [QCOW2_OL_ACTIVE_L2_BITNR] = "active L2 table",
- [QCOW2_OL_REFCOUNT_TABLE_BITNR] = "refcount table",
- [QCOW2_OL_REFCOUNT_BLOCK_BITNR] = "refcount block",
- [QCOW2_OL_SNAPSHOT_TABLE_BITNR] = "snapshot table",
- [QCOW2_OL_INACTIVE_L1_BITNR] = "inactive L1 table",
- [QCOW2_OL_INACTIVE_L2_BITNR] = "inactive L2 table",
+ [QCOW2_OL_MAIN_HEADER_BITNR] = "qcow2_header",
+ [QCOW2_OL_ACTIVE_L1_BITNR] = "active L1 table",
+ [QCOW2_OL_ACTIVE_L2_BITNR] = "active L2 table",
+ [QCOW2_OL_REFCOUNT_TABLE_BITNR] = "refcount table",
+ [QCOW2_OL_REFCOUNT_BLOCK_BITNR] = "refcount block",
+ [QCOW2_OL_SNAPSHOT_TABLE_BITNR] = "snapshot table",
+ [QCOW2_OL_INACTIVE_L1_BITNR] = "inactive L1 table",
+ [QCOW2_OL_INACTIVE_L2_BITNR] = "inactive L2 table",
+ [QCOW2_OL_BITMAP_DIRECTORY_BITNR] = "bitmap directory",
};
+QEMU_BUILD_BUG_ON(QCOW2_OL_MAX_BITNR != ARRAY_SIZE(metadata_ol_names));
/*
* First performs a check for metadata overlaps (through
