From: "Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>
To: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: "David S. Miller" <davem@davemloft.net>,
"netdev@vger.kernel.org" <netdev@vger.kernel.org>,
Linux-Renesas <linux-renesas-soc@vger.kernel.org>
Subject: Re: Regression introduced by "net: ipconfig: Support using "delayed" DHCP replies"
Date: Tue, 9 Aug 2016 12:18:19 +0200 [thread overview]
Message-ID: <20160809101819.GL17139@pengutronix.de> (raw)
In-Reply-To: <CAMuHMdVjugL0y-C+vet=qbcER8rjuFKwFgrutRUAs=uOk0JZ1A@mail.gmail.com>
Hello Geert,
On Tue, Aug 09, 2016 at 12:02:44PM +0200, Geert Uytterhoeven wrote:
> Hi Uwe, David,
>
> On current net-next, I see the following corruption during DHCP on
> r8a7791/koelsch, which uses the sh_eth driver:
>
> Sending DHCP requests ., OK
> IP-Config: Got DHCP answer from 192.168.97.254, my address is 192.168.97.28
> IP-Config: Complete:
> - device=eth0, hwaddr=2e:09:0a:00:6d:85, ipaddr=192.168.97.28,
> mask=255.255.255.0, gw=192.168.97.254
> + device=^M\xffffffc0\xffffffa0\xffffffe1,
> hwaddr=0e:9e:45:ac:dd:b4:3a:88:95:e1:50:af:0c:44:92:c0:6c:46:9f:02:34:1e:58:21:cd:c3:40:0c:ed:80:b1:74:10:0c:04:31:06:9f:04:01:04:93:5c:51:83:18:46:09,
> ipaddr=192.168.97.28, mask=255.255.255.0, gw=192.168.97.254
I fail to see the reason from looking at the patch.
Is this reproducible? Can you please enable pr_debug output and provide
the corresponding output? What is your kernel command line? Are there >1
eth devices?
I will try to reproduce and fix later today.
> It may also crash in ip_auto_config() with e.g. "Unable to handle kernel NULL
> pointer dereference at virtual address 0000017d".
>
> I've bisected this to commit 2647cffb2bc6fbed163d377390eb7ca552c7c1cb
> ('net: ipconfig: Support using "delayed" DHCP replies').
> Unfortunately just reverting that commit on current net-next is not a
> solution, as
> that may lead to DHCP failures:
>
> DHCP/BOOTP: Ignoring delayed packet
> timed out!
> [...]
> IP-Config: Retrying forever (NFS root)...
>
> Reverting also commit e068853409aa1720 ("net: ipconfig: drop inter-device
> timeout") fixes that, though.
That's not surprising. e068853409aa1720 was only possible because of
2647cffb2bc6fbed163d377390eb7ca552c7c1cb.
Best regards
Uwe
--
Pengutronix e.K. | Uwe Kleine-König |
Industrial Linux Solutions | http://www.pengutronix.de/ |
next prev parent reply other threads:[~2016-08-09 10:18 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-08-09 10:02 Regression introduced by "net: ipconfig: Support using "delayed" DHCP replies" Geert Uytterhoeven
2016-08-09 10:18 ` Uwe Kleine-König [this message]
2016-08-09 12:30 ` Geert Uytterhoeven
2016-08-10 9:44 ` [PATCH] net: ipconfig: fix use after free Uwe Kleine-König
2016-08-10 10:00 ` Geert Uytterhoeven
2016-08-10 21:55 ` David Miller
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