qcow2-refcount: check_refcounts_l1(): check reserved bits

Signed-off-by: Vladimir Sementsov-Ogievskiy <[email protected]>
Reviewed-by: Eric Blake <[email protected]>
Tested-by: Kirill Tkhai <[email protected]>
Reviewed-by: Hanna Reitz <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Hanna Reitz <[email protected]>

Author: Vladimir Sementsov-Ogievskiy

block/qcow2-refcount.c

@@ -1902,6 +1902,12 @@ static int check_refcounts_l1(BlockDriverState *bs,
             continue;
         }
 
+        if (l1_table[i] & L1E_RESERVED_MASK) {
+            fprintf(stderr, "ERROR found L1 entry with reserved bits set: "
+                    "%" PRIx64 "\n", l1_table[i]);
+            res->corruptions++;
+        }
+
         l2_offset = l1_table[i] & L1E_OFFSET_MASK;
 
         /* Mark L2 table as used */

block/qcow2.h

@@ -586,6 +586,7 @@ typedef enum QCow2MetadataOverlap {
     (QCOW2_OL_CACHED | QCOW2_OL_INACTIVE_L2)
 
 #define L1E_OFFSET_MASK 0x00fffffffffffe00ULL
+#define L1E_RESERVED_MASK 0x7f000000000001ffULL
 #define L2E_OFFSET_MASK 0x00fffffffffffe00ULL
 #define L2E_STD_RESERVED_MASK 0x3f000000000001feULL