BlockBackend has only a single pointer to its guest device, so it makes
sure that only a single guest device is attached to it. device-add
returns an error if you try to attach a second device to a BB. In order
to make the error message nicer, -device that manually connects to a
if=none block device get a different message than -drive that implicitly
creates a guest device. The if=... option is stored in DriveInfo.
However, since blockdev-add exists, not every BlockBackend has a
DriveInfo any more. Check that it exists before we dereference it.
QMP reproducer resulting in a segfault:
{"execute":"blockdev-add","arguments":{"options":{"id":"disk","driver":"file","filename":"/tmp/test.img"}}}
{"execute":"device_add","arguments":{"driver":"virtio-blk-pci","drive":"disk"}}
{"execute":"device_add","arguments":{"driver":"virtio-blk-pci","drive":"disk"}}
Signed-off-by: Kevin Wolf <[email protected]>
Reviewed-by: Eric Blake <[email protected]>
Reviewed-by: Stefan Hajnoczi <[email protected]>
---
hw/core/qdev-properties-system.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/hw/core/qdev-properties-system.c b/hw/core/qdev-properties-system.c
index 891219a..df38b8a 100644
--- a/hw/core/qdev-properties-system.c
+++ b/hw/core/qdev-properties-system.c
@@ -82,7 +82,7 @@ static void parse_drive(DeviceState *dev, const char *str,
void **ptr,
if (blk_attach_dev(blk, dev) < 0) {
DriveInfo *dinfo = blk_legacy_dinfo(blk);
- if (dinfo->type != IF_NONE) {
+ if (dinfo && dinfo->type != IF_NONE) {
error_setg(errp, "Drive '%s' is already in use because "
"it has been automatically connected to another "
"device (did you need 'if=none' in the drive options?)",
--
1.8.3.1
