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| author | Peter Lieven <pl@kamp.de> | 2013-11-12 13:48:07 +0100 |
|---|---|---|
| committer | Kevin Wolf <kwolf@redhat.com> | 2013-11-14 13:09:07 +0100 |
| commit | 78a52ad5acca7053b774fcc80290e7b7e224c80a (patch) | |
| tree | 86e84d4bf15952a68c837739be841ab8e6c44764 | |
| parent | 968854c8a106243eae7a68394ce1cb85dc138837 (diff) | |
| download | qemu-78a52ad5acca7053b774fcc80290e7b7e224c80a.zip qemu-78a52ad5acca7053b774fcc80290e7b7e224c80a.tar.gz qemu-78a52ad5acca7053b774fcc80290e7b7e224c80a.tar.bz2 | |
qcow2: fix possible corruption when reading multiple clusters
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: qemu-stable@nongnu.org
Signed-off-by: Peter Lieven <pl@kamp.de>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
| -rw-r--r-- | block/qcow2-cluster.c | 2 |
1 files changed, 1 insertions, 1 deletions
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; |