netdev - Re: [PATCH net] vxlan: fix oops in dev_fill_metadata

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 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Fri, 17 Feb 2017 19:42:10 +0100
From:   Jiri Benc <jbenc@...hat.com>
To:     Paolo Abeni <pabeni@...hat.com>
Cc:     netdev@...r.kernel.org, "David S. Miller" <davem@...emloft.net>
Subject: Re: [PATCH net] vxlan: fix oops in dev_fill_metadata_dst

On Fri, 17 Feb 2017 19:14:27 +0100, Paolo Abeni wrote:
> Since the commit 0c1d70af924b ("net: use dst_cache for vxlan device")
> vxlan_fill_metadata_dst() calls vxlan_get_route() passing a NULL
> dst_cache pointer, so the latter should explicitly check for
> valid dst_cache ptr. Unfortunately the commit d71785ffc7e7 ("net: add
> dst_cache to ovs vxlan lwtunnel") removed said check.
> 
> As a result is possible to trigger a null pointer access calling
> vxlan_fill_metadata_dst(), e.g. with:
> 
> ovs-vsctl add-br ovs-br0
> ovs-vsctl add-port ovs-br0 vxlan0 -- set interface vxlan0 \
> 	type=vxlan options:remote_ip=192.168.1.1 \
> 	options:key=1234 options:dst_port=4789 ofport_request=10
> ip address add dev ovs-br0 172.16.1.2/24
> ovs-vsctl set Bridge ovs-br0 ipfix=@i -- --id=@i create IPFIX \
> 	targets=\"172.16.1.1:1234\" sampling=1
> iperf -c 172.16.1.1 -u -l 1000 -b 10M -t 1 -p 1234
> 
> This commit addresses the issue passing to vxlan_get_route() the
> dst_cache already available into the lwt info processed by
> vxlan_fill_metadata_dst().
> 
> Fixes: d71785ffc7e7 ("net: add dst_cache to ovs vxlan lwtunnel")
> Signed-off-by: Paolo Abeni <pabeni@...hat.com>

Acked-by: Jiri Benc <jbenc@...hat.com>