Re: [PATCH 09/10] qcow2-refcount: check_refcounts_l1(): check reserved bits

[Eric Blake]

On 5/4/21 10:20 AM, Vladimir Sementsov-Ogievskiy wrote:
> Signed-off-by: Vladimir Sementsov-Ogievskiy 
> ---
>  block/qcow2.h  | 1 +
>  block/qcow2-refcount.c | 6 ++
>  2 files changed, 7 insertions(+)
> 
Reviewed-by: Eric Blake 

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.   +1-919-301-3226
Virtualization:  qemu.org | libvirt.org

[PATCH 09/10] qcow2-refcount: check_refcounts_l1(): check reserved bits

[Vladimir Sementsov-Ogievskiy]

Signed-off-by: Vladimir Sementsov-Ogievskiy 
---
 block/qcow2.h  | 1 +
 block/qcow2-refcount.c | 6 ++
 2 files changed, 7 insertions(+)

diff --git a/block/qcow2.h b/block/qcow2.h
index b8b1093b61..58fd7f1678 100644
--- a/block/qcow2.h
+++ b/block/qcow2.h
@@ -586,6 +586,7 @@ typedef enum QCow2MetadataOverlap {
 (QCOW2_OL_CACHED | QCOW2_OL_INACTIVE_L2)
 
 #define L1E_OFFSET_MASK 0x00fffe00ULL
+#define L1E_RESERVED_MASK 0x7f0001ffULL
 #define L2E_OFFSET_MASK 0x00fffe00ULL
 #define L2E_STD_RESERVED_MASK 0x3f0001feULL
 
diff --git a/block/qcow2-refcount.c b/block/qcow2-refcount.c
index eb6de3dabd..9a20aac0c9 100644
--- a/block/qcow2-refcount.c
+++ b/block/qcow2-refcount.c
@@ -1903,6 +1903,12 @@ 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, l1_table[i]);
+res->corruptions++;
+}
+
 l2_offset = l1_table[i] & L1E_OFFSET_MASK;
 
 /* Mark L2 table as used */
-- 
2.29.2