On Tue, Sep 9, 2025 at 7:04 AM Eric Dumazet <edumazet@xxxxxxxxxx> wrote:
>
> On Tue, Sep 9, 2025 at 6:32 AM Richard W.M. Jones <rjones@xxxxxxxxxx> wrote:
> >
> > On Tue, Sep 09, 2025 at 01:22:43PM +0000, Eric Dumazet wrote:
> > > Recently, syzbot started to abuse NBD with all kinds of sockets.
> > >
> > > Commit cf1b2326b734 ("nbd: verify socket is supported during setup")
> > > made sure the socket supported a shutdown() method.
> > >
> > > Explicitely accept TCP and UNIX stream sockets.
> >
> > I'm not clear what the actual problem is, but I will say that libnbd &
> > nbdkit (which are another NBD client & server, interoperable with the
> > kernel) we support and use NBD over vsock[1]. And we could support
> > NBD over pretty much any stream socket (Infiniband?) [2].
> >
> > [1] https://libguestfs.org/nbd_aio_connect_vsock.3.html
> > https://libguestfs.org/nbdkit-service.1.html#AF_VSOCK
> > [2] https://libguestfs.org/nbd_connect_socket.3.html
> >
> > TCP and Unix domain sockets are by far the most widely used, but I
> > don't think it's fair to exclude other socket types.
>
> If we have known and supported socket types, please send a patch to add them.
>
> I asked the question last week and got nothing about vsock or other types.
>
> https://lore.kernel.org/netdev/CANn89iLNFHBMTF2Pb6hHERYpuih9eQZb6A12+ndzBcQs_kZoBA@xxxxxxxxxxxxxx/
>
> For sure, we do not want datagram sockets, RAW, netlink, and many others.
BTW vsock will probably fire lockdep warnings, I see GFP_KERNEL being used
in net/vmw_vsock/virtio_transport.c
So you will have to fix this.
