block/mirror: check backing in bdrv_mirror_top_flush
commitce960aa9062a407d0ca15aee3dcd3bd84a4e24f9
authorVladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Fri, 29 Sep 2017 15:22:55 +0000 (29 18:22 +0300)
committerMax Reitz <mreitz@redhat.com>
Fri, 6 Oct 2017 14:30:48 +0000 (6 16:30 +0200)
tree1ba071735ea70c9095cd9ab33d6b8a32f21585f7
parent163bc39d2c2921430e5c23f4d0a0966d62f67a02
block/mirror: check backing in bdrv_mirror_top_flush

Backing may be zero after failed bdrv_append in mirror_start_job,
which leads to SIGSEGV.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20170929152255.5431-1-vsementsov@virtuozzo.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
block/mirror.c