From: Stephen Hemminger <stephen@networkplumber.org>
To: netdev@vger.kernel.org
Subject: Fw: [Bug 206885] New: macvlan and proxy ARP can be accidentally configured to respond to ARP requests for all IPs
Date: Thu, 19 Mar 2020 07:58:39 -0700 [thread overview]
Message-ID: <20200319075839.0af55790@hermes.lan> (raw)
My gut feeling is this a user error, but forwarding to get more eyes.
Begin forwarded message:
Date: Thu, 19 Mar 2020 13:48:01 +0000
From: bugzilla-daemon@bugzilla.kernel.org
To: stephen@networkplumber.org
Subject: [Bug 206885] New: macvlan and proxy ARP can be accidentally configured to respond to ARP requests for all IPs
https://bugzilla.kernel.org/show_bug.cgi?id=206885
Bug ID: 206885
Summary: macvlan and proxy ARP can be accidentally configured
to respond to ARP requests for all IPs
Product: Networking
Version: 2.5
Kernel Version: 5.3.0-42-generic
Hardware: All
OS: Linux
Tree: Mainline
Status: NEW
Severity: normal
Priority: P1
Component: IPV4
Assignee: stephen@networkplumber.org
Reporter: thomas.parrott@canonical.com
Regression: No
Using the following approach it is possible to accidentally configure a macvlan
interface to respond to ARP requests for all IPs.
Reproducer:
ip link add link enp3s0 address f6:83:72:e4:77:0a vtest type macvlan
ip addr add 192.168.1.200/32 dev vtest
ip link set vtest up
sysctl -w net.ipv4.conf.vtest.rp_filter=2
sysctl -w net.ipv4.conf.vtest.proxy_arp=1
sysctl -w net.ipv4.conf.vtest.forwarding=1
On a separate host on the same segment:
arping -c 1 -I eth1 -s 192.168.1.2 10.1.2.3
ARPING 10.1.2.3 from 192.168.1.2 eth1
Unicast reply from 10.1.2.3 [f6:83:72:e4:77:0a] 419.288ms
Sent 1 probe(s) (0 broadcast(s))
Received 1 response(s) (0 request(s), 0 broadcast(s))
arping -c 1 -I eth1 -s 192.168.1.2 8.8.8.8
ARPING 10.1.2.3 from 192.168.1.2 eth1
Unicast reply from 10.1.2.3 [f6:83:72:e4:77:0a] 27.754ms
Sent 1 probe(s) (0 broadcast(s))
Received 1 response(s) (0 request(s), 0 broadcast(s))
See https://github.com/lxc/lxc/issues/775 for more information.
--
You are receiving this mail because:
You are the assignee for the bug.
reply other threads:[~2020-03-19 14:58 UTC|newest]
Thread overview: [no followups] expand[flat|nested] mbox.gz Atom feed
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20200319075839.0af55790@hermes.lan \
--to=stephen@networkplumber.org \
--cc=netdev@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).