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[Qemu-devel] [PULL 07/11] qcow2: fix possible corruption when reading mu
From: |
Kevin Wolf |
Subject: |
[Qemu-devel] [PULL 07/11] qcow2: fix possible corruption when reading multiple clusters |
Date: |
Fri, 15 Nov 2013 18:53:15 +0100 |
From: Peter Lieven <address@hidden>
if multiple sectors spanning multiple clusters are read the
function count_contiguous_clusters should ensure that the
cluster type should not change between the clusters.
Especially the for-loop should break when we have one
or more normal clusters followed by a compressed cluster.
Unfortunately the wrong macro was used in the mask to
compare the flags.
This was discovered while debugging a data corruption
issue when converting a compressed qcow2 image to raw.
qemu-img reads 2MB chunks which span multiple clusters.
CC: address@hidden
Signed-off-by: Peter Lieven <address@hidden>
Signed-off-by: Kevin Wolf <address@hidden>
---
block/qcow2-cluster.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c
index f242244..791083a 100644
--- a/block/qcow2-cluster.c
+++ b/block/qcow2-cluster.c
@@ -290,7 +290,7 @@ static int count_contiguous_clusters(uint64_t nb_clusters,
int cluster_size,
uint64_t *l2_table, uint64_t stop_flags)
{
int i;
- uint64_t mask = stop_flags | L2E_OFFSET_MASK | QCOW2_CLUSTER_COMPRESSED;
+ uint64_t mask = stop_flags | L2E_OFFSET_MASK | QCOW_OFLAG_COMPRESSED;
uint64_t first_entry = be64_to_cpu(l2_table[0]);
uint64_t offset = first_entry & mask;
--
1.8.1.4
- [Qemu-devel] [PULL 00/11] Block fixes for 1.7.0, Kevin Wolf, 2013/11/15
- [Qemu-devel] [PULL 02/11] qapi-schema: Update description for NewImageMode, Kevin Wolf, 2013/11/15
- [Qemu-devel] [PULL 01/11] block: Print its file name if backing file opening failed, Kevin Wolf, 2013/11/15
- [Qemu-devel] [PULL 03/11] block/drive-mirror: Check for NULL backing_hd, Kevin Wolf, 2013/11/15
- [Qemu-devel] [PULL 05/11] MAINTAINERS: add block tree repo URLs, Kevin Wolf, 2013/11/15
- [Qemu-devel] [PULL 04/11] qemu-iotests: Extend 041 for unbacked mirroring, Kevin Wolf, 2013/11/15
- [Qemu-devel] [PULL 07/11] qcow2: fix possible corruption when reading multiple clusters,
Kevin Wolf <=
- [Qemu-devel] [PULL 06/11] qmp: access the local QemuOptsLists for drive option, Kevin Wolf, 2013/11/15
- [Qemu-devel] [PULL 08/11] qemu-iotests: Test qcow2 count_contiguous_clusters(), Kevin Wolf, 2013/11/15
- [Qemu-devel] [PULL 10/11] MAINTAINERS: add block driver sub-maintainers, Kevin Wolf, 2013/11/15
- [Qemu-devel] [PULL 09/11] qemu-img: Fix overwriting 'ret' before using, Kevin Wolf, 2013/11/15
- [Qemu-devel] [PULL 11/11] block: Fail if requested driver is not available, Kevin Wolf, 2013/11/15