In vu_message_write() we use sendmsg() to send the message header, then a write() to send the payload.
If sendmsg() fails we should avoid sending the payload, since we were unable to send the header. Discovered before fixing the issue with the previous patch, where sendmsg() failed on macOS due to wrong parameters, but the frontend still sent the payload which the backend incorrectly interpreted as a wrong header. Reviewed-by: Daniel P. Berrangé <[email protected]> Reviewed-by: Philippe Mathieu-Daudé <[email protected]> Tested-by: Philippe Mathieu-Daudé <[email protected]> Acked-by: Stefan Hajnoczi <[email protected]> Reviewed-by: David Hildenbrand <[email protected]> Signed-off-by: Stefano Garzarella <[email protected]> --- subprojects/libvhost-user/libvhost-user.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/subprojects/libvhost-user/libvhost-user.c b/subprojects/libvhost-user/libvhost-user.c index 22bea0c775..a11afd1960 100644 --- a/subprojects/libvhost-user/libvhost-user.c +++ b/subprojects/libvhost-user/libvhost-user.c @@ -639,6 +639,11 @@ vu_message_write(VuDev *dev, int conn_fd, VhostUserMsg *vmsg) rc = sendmsg(conn_fd, &msg, 0); } while (rc < 0 && (errno == EINTR || errno == EAGAIN)); + if (rc <= 0) { + vu_panic(dev, "Error while writing: %s", strerror(errno)); + return false; + } + if (vmsg->size) { do { if (vmsg->data) { -- 2.45.1
