netdev - Re: r8169 nic sometimes doesn't work after changing the mac address

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] [day] [month] [year] [list]

Message-ID: <2548019.66mqNrkh6O@fuchs>
Date:	Sat, 20 Feb 2016 21:54:23 +0100
From:	Maximilian Engelhardt <maxi@...monizer.de>
To:	Realtek linux nic maintainers <nic_swsd@...ltek.com>
Cc:	netdev@...r.kernel.org
Subject: Re: r8169 nic sometimes doesn't work after changing the mac address

On Saturday 12 December 2015 22:43:45 Maximilian Engelhardt wrote:
> Hello,
> 
> I'm using a Lenovo TinkPad Edge E135 notebook that has a Realtek wired
> network interface inbuilt. Under some conditions the nic doesn't work after
> changing the mac address.
> 
> It took me some time to figure out that it makes a difference if I (re)boot
> my notebook with or without the power supply plugged in. When I boot the
> system with the power supply plugged in everything does work fine as
> expected. But if I boot with the power supply unplugged and I change the
> mac address the network card doesn't work.
> 
> 
> This is how I am testing and how I can reproduce the behavior on my system:
> 
> * Boot Linux (Debian stable with a newer kernel)
> * Network is still turned off, only loopback is enabled by default in my
> setup. * I run the following commands:
>   ip link set dev eth0 address 00:12:0c:96:a7:2e # a randomly generated mac
>   ip link set dev eth0 up
>   ip addr add dev eth0 10.0.252.50/24
>   ip route add default via 10.0.252.1
> 
> When the notebook is booted with the power supply plugged in the network is
> working as expected, e. g. I can ping the gateway.
> 
> But when the notebook was booted without the power supply attached the
> network is not working e. g. pinging the gateway doesn't get any replies.
> 
> I found two ways to get the network working from this state (beside
> rebooting with power plugged in):
> 
> * If I enable promiscous mode the network connections are working again:
>   # ip link set dev eth0 promisc on
> 
> * Alternatively I can set the same mac address again while the interface is
> up:
>   # ip link set dev eth0 address 00:12:0c:96:a7:2e # same mac as before
> 
> 
> So it seems like a mac filter in the network card is not set up right.
> 
> 
> Attached are dmesg output of a boot with and without power supply attached
> as well as the output of lspci -vvv.
> 
> 
> Please let me know If you need more information.
> 
> Thanks,
> Maxi


Hello,

Anyone had a look at this? I can confirm that the problem is still present in 
kernel 4.4.2.

I just did a quick tcpdump and found out that packets are transmitted fine, but 
the replay of the other end gets lost somewhere in the nic/driver e. i. it 
seems to never reach the kernel network stack.

Please let me know if you need more information from me.

Thanks,
Maxi

Download attachment "signature.asc" of type "application/pgp-signature" (820 bytes)