diff mbox series

[v5,02/13] libvhost-user: fail vu_message_write() if sendmsg() is failing

Message ID 20240523145522.313012-3-sgarzare@redhat.com
State New
Headers show
Series vhost-user: support any POSIX system (tested on macOS, FreeBSD, OpenBSD) | expand

Commit Message

Stefano Garzarella May 23, 2024, 2:55 p.m. UTC 
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 <berrange@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Tested-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
---
 subprojects/libvhost-user/libvhost-user.c | 5 +++++
 1 file changed, 5 insertions(+)

Comments

David Hildenbrand May 23, 2024, 3 p.m. UTC | #1 
On 23.05.24 16:55, Stefano Garzarella wrote:
> 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 <berrange@redhat.com>
> Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
> Tested-by: Philippe Mathieu-Daudé <philmd@linaro.org>
> Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
> Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
> ---

Reviewed-by: David Hildenbrand <david@redhat.com>
diff mbox series

Patch

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) {