From 92b58bc7e9086e489295040d408118a81c47b31d Mon Sep 17 00:00:00 2001 From: Stefano Garzarella Date: Tue, 18 Jun 2024 12:00:33 +0200 Subject: [PATCH] libvhost-user: fail vu_message_write() if sendmsg() is failing MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit 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 Reviewed-by: Philippe Mathieu-Daudé Tested-by: Philippe Mathieu-Daudé Acked-by: Stefan Hajnoczi Reviewed-by: David Hildenbrand Signed-off-by: Stefano Garzarella Message-Id: <20240618100043.144657-4-sgarzare@redhat.com> Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin --- 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 53bf1adda6..ea27683dac 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) { -- 2.30.2