From: Stefano Garzarella <sgarz...@redhat.com> libvhost-user will panic when receiving VHOST_USER_GET_INFLIGHT_FD message if MFD_ALLOW_SEALING is not defined, since it's not able to create a memfd.
VHOST_USER_GET_INFLIGHT_FD is used only if VHOST_USER_PROTOCOL_F_INFLIGHT_SHMFD is negotiated. So, let's mask that feature if the backend is not able to properly handle these messages. Reviewed-by: Philippe Mathieu-Daudé <phi...@linaro.org> Tested-by: Philippe Mathieu-Daudé <phi...@linaro.org> Acked-by: Stefan Hajnoczi <stefa...@redhat.com> Reviewed-by: David Hildenbrand <da...@redhat.com> Signed-off-by: Stefano Garzarella <sgarz...@redhat.com> Message-Id: <20240618100043.144657-5-sgarz...@redhat.com> Reviewed-by: Michael S. Tsirkin <m...@redhat.com> Signed-off-by: Michael S. Tsirkin <m...@redhat.com> --- subprojects/libvhost-user/libvhost-user.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/subprojects/libvhost-user/libvhost-user.c b/subprojects/libvhost-user/libvhost-user.c index ea27683dac..9c630c2170 100644 --- a/subprojects/libvhost-user/libvhost-user.c +++ b/subprojects/libvhost-user/libvhost-user.c @@ -1674,6 +1674,17 @@ vu_get_protocol_features_exec(VuDev *dev, VhostUserMsg *vmsg) features |= dev->iface->get_protocol_features(dev); } +#ifndef MFD_ALLOW_SEALING + /* + * If MFD_ALLOW_SEALING is not defined, we are not able to handle + * VHOST_USER_GET_INFLIGHT_FD messages, since we can't create a memfd. + * Those messages are used only if VHOST_USER_PROTOCOL_F_INFLIGHT_SHMFD + * is negotiated. A device implementation can enable it, so let's mask + * it to avoid a runtime panic. + */ + features &= ~(1ULL << VHOST_USER_PROTOCOL_F_INFLIGHT_SHMFD); +#endif + vmsg_set_reply_u64(vmsg, features); return true; } -- MST