From: Simon Kelley <simon@thekelleys.org.uk>
To: LKML <linux-kernel@vger.kernel.org>
Cc: simon@thekelleys.org.uk
Subject: Oops in dev_get_by_index.
Date: Tue, 22 Jun 2004 19:57:02 +0100 [thread overview]
Message-ID: <40D880FE.6090708@thekelleys.org.uk> (raw)
I've received a bug-report that dnsmasq
(http://www.thekelleys.org.uk/dnsmasq) is provoking a kernel Oops and
I'm posting everything I know about it here in the hope that someone who
knows the relevant code will be able to see instantly what the problem is.
The Oops looks like this:
CPU: 0
EIP: 0060:[<02237d52>] Not tainted
EFLAGS: 00010202 (2.6.6-1.435)
EIP is at __dev_get_by_index+0x14/0x2b
eax: 10a64134 ebx: 02cabef8 ecx: 00000006 edx: 00000000
esi: 075ab000 edi: 00008910 ebp: fef735e0 esp: 02cabef0
ds: 007b es: 007b ss: 0068
Process dnsmasq (pid: 7524, threadinfo=02cab000 task=0e3f7270)
Stack: 02238e9a 00000000 00000000 00000000 080570eb 0977bdd0 00000006
fef73608
00ae007e 00b44ffc fef735e0 075ab000 00008910 02266641 02239733 fef735e0
00000008 00000000 11566b80 09774436 000001da 02cabf70 0000000c 0000000c
Call Trace:
[<02238e9a>] dev_ifname+0x30/0x66
[<02266641>] udp_ioctl+0x0/0x6e
[<02239733>] dev_ioctl+0x83/0x283
[<02266641>] udp_ioctl+0x0/0x6e
[<0226c323>] inet_ioctl+0x6e/0x73
[<02232936>] sock_ioctl+0x26d/0x285
[<0214f7f6>] sys_ioctl+0x1f2/0x224
Code: 0f 18 02 90 2d 34 01 00 00 39 48 34 74 08 85 d2 89 d0 75 ea
This is the kernel part of the ioctl in dnsmasq-2.8/src/forward.c which does
ifr.ifr_ifindex = if_index;
ioctl(fd, SIOCGIFNAME, &ifr)
were the fd is a UDP socket which has had recvmsg called to get the
datagram and IP_PKTINFO auxiliary data from which the if_index is derived.
The kernel version in question is 2.6.6-1.435 from Fedora.
There's a possibility if IPv6 involvement. The kernel has IPv6 loaded
and the network interfaces have IPv6 addresses. Under those
circumstances dnsmasq will bind the IPv6 addresses automatically. I have
no way of telling if the Oops was as a result of receiving an IPv6
datagram, but it is unlikely since IPv6 is not in active use.
The Oops happens rarely: there is no known way to reproduce it on demand.
That's all the information I have: can anybody spot a problem?
Cheers,
Simon.
reply other threads:[~2004-06-22 19:04 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=40D880FE.6090708@thekelleys.org.uk \
--to=simon@thekelleys.org.uk \
--cc=linux-kernel@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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.