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-Tag: qemu-xen-4.13.1~2^2~40 X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=783e7eb52c0a8e2b8cb906566d0dc2538ffefccf;p=qemu-xen.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 (cherry picked from commit 1048ddf0a32dcdaa952e581bd503d49adad527cc) Signed-off-by: Michael Roth --- diff --git a/block/backup.c b/block/backup.c index 7067d1d1ad..8761f1f9a7 100644 --- a/block/backup.c +++ b/block/backup.c @@ -167,7 +167,7 @@ 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); hbitmap_reset(job->copy_bitmap, start, job->cluster_size * nr_clusters); ret = blk_co_copy_range(blk, start, job->target, start, nbytes,