> -----Original Message-----
> From: Tomas Hozza [mailto:tho...@redhat.com]
> Sent: Tuesday, November 06, 2012 2:55 PM
> To: KY Srinivasan
> Cc: Olaf Hering; gre...@linuxfoundation.org; linux-kernel@vger.kernel.org;
> de...@linuxdriverproject.org; a...@canonical.com; jasow...@redhat.com
> Subject: Re: [PATCH] tools/hv/hv_kvp_daemon.c: Netlink source address
> validation allows DoS
>
> From 6199072f8131056efce208f04e6985d1f9968d8e Mon Sep 17 00:00:00 2001
> From: Tomas Hozza <tho...@redhat.com>
> Date: Mon, 5 Nov 2012 10:08:16 +0100
> Subject: [PATCH] Netlink source address validation allows DoS
>
> The source code without this patch caused hypervkvpd to exit when it processed
> a spoofed Netlink packet which has been sent from an untrusted local user.
> Netlink messages with a non-zero nl_pid source address should just be ignored.
Thomas,
You need a Signed-off-by line. Please refer to the documentation on how to
submit a patch.
Regards,
K. Y
> ---
> tools/hv/hv_kvp_daemon.c | 8 +++++++-
> 1 file changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/tools/hv/hv_kvp_daemon.c b/tools/hv/hv_kvp_daemon.c
> index 3ea3af2..7d74497 100755
> --- a/tools/hv/hv_kvp_daemon.c
> +++ b/tools/hv/hv_kvp_daemon.c
> @@ -1478,13 +1478,19 @@ int main(void)
> len = recvfrom(fd, kvp_recv_buffer, sizeof(kvp_recv_buffer), 0,
> addr_p, &addr_l);
>
> - if (len < 0 || addr.nl_pid) {
> + if (len < 0) {
> syslog(LOG_ERR, "recvfrom failed; pid:%u error:%d %s",
> addr.nl_pid, errno, strerror(errno));
> close(fd);
> return -1;
> }
>
> + if (addr.nl_pid) {
> + syslog(LOG_WARNING, "Received packet from untrusted
> pid:%u",
> + addr.nl_pid);
> + continue;
> + }
> +
> incoming_msg = (struct nlmsghdr *)kvp_recv_buffer;
> incoming_cn_msg = (struct cn_msg
> *)NLMSG_DATA(incoming_msg);
> hv_msg = (struct hv_kvp_msg *)incoming_cn_msg->data;
> --
> 1.7.11.7
>
> ----- Original Message -----
> >
> >
> > > -----Original Message-----
> > > From: Tomas Hozza [mailto:tho...@redhat.com]
> > > Sent: Tuesday, November 06, 2012 10:21 AM
> > > To: gre...@linuxfoundation.org; linux-kernel@vger.kernel.org;
> > > de...@linuxdriverproject.org; a...@canonical.com;
> > > jasow...@redhat.com
> > > Cc: Olaf Hering; KY Srinivasan
> > > Subject: [PATCH] tools/hv/hv_kvp_daemon.c: Netlink source address
> > > validation
> > > allows DoS
> > >
> > > Hi.
> > >
> > > After discussion with KY Srinivasan and Olaf Hering I'm sending you
> > > a patch for the HyperV KVP daemon distributed in linux kernel
> > > "tools/hv/hv_kvp_daemon.c".
> > >
> > > There is an issue in the current daemon source causing hyperv kvp
> > > daemon
> > > to exit when it processes a spoofed Netlink packet which has been
> > > sent
> > > from an untrusted local user.
> > >
> > > This patch is fixing this, so now the Netlink messages with a
> > > non-zero
> > > nl_pid source address are just ignored.
> >
> > You don't want to send the patch as an attachment. Please send the
> > patch
> > as part of the mail.
> >
> > Regards,
> >
> > K. Y
> > >
> > >
> > > Regards,
> > >
> > > Tomas Hozza
> > > Associate Software Engineer
> > > BaseOS - Brno, CZ
> >
>
