On 03/01/2023 13:13, Dr. David Alan Gilbert wrote:
External email: Use caution opening links or attachments * Avihai Horon (avih...@nvidia.com) wrote: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> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsement...@yandex-team.ru>It might be worth posting this patch separately since it's a simple fix and should go in sooner.
Sure, I will wait for Alex's feedback on the series and consider sending it separately.
Thanks.
Dave--- 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 e1413ac90c..09fe7c1de2 100644 --- a/hw/vfio/migration.c +++ b/hw/vfio/migration.c @@ -743,7 +743,9 @@ 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), -- 2.26.3-- Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK
