diff mbox series

[v5,03/13] libvhost-user: mask F_INFLIGHT_SHMFD if memfd is not supported

Message ID 20240523145522.313012-4-sgarzare@redhat.com (mailing list archive)
State New, archived
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 
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 <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 | 11 +++++++++++
 1 file changed, 11 insertions(+)

Comments

David Hildenbrand May 23, 2024, 3 p.m. UTC | #1 
On 23.05.24 16:55, Stefano Garzarella wrote:
> 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 <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 a11afd1960..2c20cdc16e 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;
 }