[Qemu-stable] [PATCH for-1.4] s390-virtio: Check for NULL device in reset hypercall

[Andreas Färber]

s390_virtio_bus_find_mem() may return a NULL VirtIOS390Device.
If called with, e.g., args[0] == 0, this leads to a segfault.
Fix this by adding error handling as done for other hypercalls.

Present since baf0b55a9e57b909b1f8b0f732c0b10242867418 (Implement
virtio reset).

Cc: address@hidden
Signed-off-by: Andreas Färber <address@hidden>
---
 hw/s390-virtio.c |    3 +++
 1 Datei geändert, 3 Zeilen hinzugefügt(+)

diff --git a/hw/s390-virtio.c b/hw/s390-virtio.c
index 5edaabb..5d48aba 100644
--- a/hw/s390-virtio.c
+++ b/hw/s390-virtio.c
@@ -86,6 +86,9 @@ static int s390_virtio_hcall_reset(const uint64_t *args)
     VirtIOS390Device *dev;
 
     dev = s390_virtio_bus_find_mem(s390_bus, mem);
+    if (dev == NULL) {
+        return -EINVAL;
+    }
     virtio_reset(dev->vdev);
     stb_phys(dev->dev_offs + VIRTIO_DEV_OFFS_STATUS, 0);
     s390_virtio_device_sync(dev);
-- 
1.7.10.4