virtio-scsi: don't crash without a valid device

Make sure that we actually have a device when checking the aio
context. Otherwise guests could trigger QEMU crashes.

Signed-off-by: "Eugene (jno) Dvurechenski" <jno@linux.vnet.ibm.com>
Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Message-Id: <1448549135-6582-2-git-send-email-jno@linux.vnet.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/hw/scsi/virtio-scsi.c b/hw/scsi/virtio-scsi.c
index 76554011cbffb4c940514d9d98b09255c81ff51d..3a4f520fbb08a44c4551f0c4e8ba5963ff43e312 100644 (file)
--- a/hw/scsi/virtio-scsi.c
+++ b/hw/scsi/virtio-scsi.c
@@ -250,7 +250,7 @@ static int virtio_scsi_do_tmf(VirtIOSCSI *s, VirtIOSCSIReq *req)
     int target;
     int ret = 0;
 
-    if (s->dataplane_started) {
+    if (s->dataplane_started && d) {
         assert(blk_get_aio_context(d->conf.blk) == s->ctx);
     }
     /* Here VIRTIO_SCSI_S_OK means "FUNCTION COMPLETE".  */