From: Vladimir Sementsov-Ogievskiy Date: Fri, 20 Sep 2019 14:20:43 +0000 (+0300) Subject: block/backup: fix backup_cow_with_offload for last cluster X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=1048ddf0a32dcdaa952e581bd503d49adad527cc;p=qemu.git block/backup: fix backup_cow_with_offload for last cluster We shouldn't try to copy bytes beyond EOF. Fix it. Fixes: 9ded4a0114968e Signed-off-by: Vladimir Sementsov-Ogievskiy Reviewed-by: Max Reitz Reviewed-by: John Snow Message-id: 20190920142056.12778-3-vsementsov@virtuozzo.com Signed-off-by: Max Reitz --- diff --git a/block/backup.c b/block/backup.c index db20249063..99177f03f8 100644 --- a/block/backup.c +++ b/block/backup.c @@ -161,7 +161,7 @@ static int coroutine_fn backup_cow_with_offload(BackupBlockJob *job, assert(QEMU_IS_ALIGNED(job->copy_range_size, job->cluster_size)); assert(QEMU_IS_ALIGNED(start, job->cluster_size)); - nbytes = MIN(job->copy_range_size, end - start); + nbytes = MIN(job->copy_range_size, MIN(end, job->len) - start); nr_clusters = DIV_ROUND_UP(nbytes, job->cluster_size); bdrv_reset_dirty_bitmap(job->copy_bitmap, start, job->cluster_size * nr_clusters);