As part of its error flow, vfio_vmstate_change() accesses
MigrationState->to_dst_file without any checks. This can cause a NULL
pointer dereference if the error flow is taken and
MigrationState->to_dst_file is not set.
For example, this can happen if VM is started or stopped not during
migration and vfio_vmstate_change() error flow is taken, as
MigrationState->to_dst_file is not set at that time.
Fix it by checking that MigrationState->to_dst_file is set before using
it.
Fixes: 02a7e71b1e5b ("vfio: Add VM state change handler to know state of VM")
Signed-off-by: Avihai Horon <avih...@nvidia.com>
Reviewed-by: Juan Quintela <quint...@redhat.com>
---
hw/vfio/migration.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/hw/vfio/migration.c b/hw/vfio/migration.c
index 8ae1bd31a8..f5e72c7ac1 100644
--- a/hw/vfio/migration.c
+++ b/hw/vfio/migration.c
@@ -740,7 +740,9 @@ static void vfio_vmstate_change(void *opaque, bool running,
RunState state)
*/
error_report("%s: Failed to set device state 0x%x", vbasedev->name,
(migration->device_state & mask) | value);
- qemu_file_set_error(migrate_get_current()->to_dst_file, ret);
+ if (migrate_get_current()->to_dst_file) {
+ qemu_file_set_error(migrate_get_current()->to_dst_file, ret);
+ }
}
vbasedev->migration->vm_running = running;
trace_vfio_vmstate_change(vbasedev->name, running, RunState_str(state),
--
2.21.3
