scsi: scsi_bus_legacy_handle_cmdline() can fail, fix callers

None of its callers checks for failure.  scsi_hot_add() can crash
because of that:

(qemu) drive_add 4 if=scsi,format=host_device,file=/dev/sg1
scsi-generic: scsi generic interface too old
Segmentation fault (core dumped)

Fix all callers, not just scsi_hot_add().

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/hw/usb-msd.c b/hw/usb-msd.c
index 003bd8a..8e9718c 100644
--- a/hw/usb-msd.c
+++ b/hw/usb-msd.c
@@ -531,6 +531,9 @@ static int usb_msd_initfn(USBDevice *dev)
     s->dev.speed = USB_SPEED_FULL;
     scsi_bus_new(&s->bus, &s->dev.qdev, 0, 1, usb_msd_command_complete);
     s->scsi_dev = scsi_bus_legacy_add_drive(&s->bus, s->conf.dinfo, 0);
+    if (!s->scsi_dev) {
+        return -1;
+    }
     s->bus.qbus.allow_hotplug = 0;
     usb_msd_handle_reset(dev);