From ee18e730234792b33e01d47939f4c30f29c9744e Mon Sep 17 00:00:00 2001 From: Frediano Ziglio Date: Sat, 10 Sep 2011 10:23:56 +0200 Subject: [PATCH] qcow2: fix range check QCowL2Meta::offset is not cluster aligned but only sector aligned however nb_clusters count cluster from cluster start. This fix range check. Note that old code have no corruption issues related to this check cause it only cause intersection to occur when shouldn't. Signed-off-by: Frediano Ziglio Signed-off-by: Kevin Wolf --- block/qcow2-cluster.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c index 428b5ad..2f76311 100644 --- a/block/qcow2-cluster.c +++ b/block/qcow2-cluster.c @@ -776,17 +776,17 @@ again: */ QLIST_FOREACH(old_alloc, &s->cluster_allocs, next_in_flight) { - uint64_t end_offset = offset + nb_clusters * s->cluster_size; - uint64_t old_offset = old_alloc->offset; - uint64_t old_end_offset = old_alloc->offset + - old_alloc->nb_clusters * s->cluster_size; + uint64_t start = offset >> s->cluster_bits; + uint64_t end = start + nb_clusters; + uint64_t old_start = old_alloc->offset >> s->cluster_bits; + uint64_t old_end = old_start + old_alloc->nb_clusters; - if (end_offset < old_offset || offset > old_end_offset) { + if (end < old_start || start > old_end) { /* No intersection */ } else { - if (offset < old_offset) { + if (start < old_start) { /* Stop at the start of a running allocation */ - nb_clusters = (old_offset - offset) >> s->cluster_bits; + nb_clusters = old_start - start; } else { nb_clusters = 0; } -- 2.7.4