lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [day] [month] [year] [list]
Date:   Wed, 6 Mar 2019 17:02:16 +0000
From:   Stefan Hajnoczi <stefanha@...hat.com>
To:     Adalbert Lazăr <alazar@...defender.com>
Cc:     Stefan Hajnoczi <stefanha@...il.com>,
        "David S . Miller" <davem@...emloft.net>,
        Stefano Garzarella <sgarzare@...hat.com>,
        virtualization@...ts.linux-foundation.org, kvm@...r.kernel.org,
        netdev@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] vsock/virtio: fix kernel panic from
 virtio_transport_reset_no_sock

On Wed, Mar 06, 2019 at 11:10:41AM +0200, Adalbert Lazăr wrote:
> On Wed, 6 Mar 2019 08:41:04 +0000, Stefan Hajnoczi <stefanha@...il.com> wrote:
> > On Tue, Mar 05, 2019 at 08:01:45PM +0200, Adalbert Lazăr wrote:
> > The pkt argument is the received packet that we must reply to.
> > The reply packet is allocated just before line 680 and must be free
> > explicitly for return -ENOTCONN.
> > 
> > You can avoid the leak and make the code easier to read like this:
> > 
> >   struct virtio_vsock_pkt *reply;
> > 
> >   ...
> > 
> >      ------ avoid reusing 'pkt'
> >     v
> >   reply = virtio_transport_alloc_pkt(&info, 0, ...);
> >   if (!reply)
> >       return -ENOMEM;
> > 
> >   t = virtio_transport_get_ops();
> >   if (!t) {
> >       virtio_transport_free_pkt(reply); <-- prevent memory leak
> >       return -ENOTCONN;
> >   }
> >   return t->send_pkt(reply);
> 
> What do you think about Stefano's suggestion, to move the check above
> the line were the reply is allocated?

That's fine too.

However a follow up patch to eliminate the confusing way that 'pkt' is
reused is still warranted.  If you are busy I'd be happy to send that
cleanup.

Stefan

Download attachment "signature.asc" of type "application/pgp-signature" (456 bytes)

Powered by blists - more mailing lists