From: Ben Greear <greearb@candelatech.com>
To: Eric Dumazet <eric.dumazet@gmail.com>
Cc: netdev <netdev@vger.kernel.org>,
"linux-nfs@vger.kernel.org" <linux-nfs@vger.kernel.org>
Subject: Re: 3.7.3+: Bad paging request in ip_rcv_finish while running NFS traffic.
Date: Wed, 23 Jan 2013 15:55:09 -0800 [thread overview]
Message-ID: <5100785D.8040101@candelatech.com> (raw)
In-Reply-To: <50FF4BC9.1060206@candelatech.com>
On 01/22/2013 06:32 PM, Ben Greear wrote:
So, I'm slowly making some progress. I've verified that the skb
has bogus dst (0xdeadbeef) at the top of the ip_rcv_finish
method. I'm trying to track it backwards and figure out which
device it belongs to, etc....takes a while to reproduce though.
One thing about this stack trace below...the dev_seq_stop() does
a rcu read-unlock. Now, I can't figure out exactly how ip_rcv()
can cause dev_seq_stop() to run, but if this stack is legit,
then maybe by the time we enter the ip_rcv_finish() code we are
running without rcu_readlock() held?
If so, that would probably explain the bug.
> Call Trace:
> [<ffffffff814a8b02>] ? ip_rcv_finish+0x2f0/0x308
> [<ffffffff814a8812>] ? skb_dst+0x5a/0x5a
> [<ffffffff814a8eb5>] NF_HOOK.clone.1+0x4c/0x54
> [<ffffffff81472e61>] ? dev_seq_stop+0xb/0xb
> [<ffffffff814a9142>] ip_rcv+0x237/0x269
> [<ffffffff81473def>] __netif_receive_skb+0x487/0x530
> [<ffffffff81473f91>] process_backlog+0xf9/0x1da
> [<ffffffff8147639a>] net_rx_action+0xad/0x218
> [<ffffffff8108d50a>] __do_softirq+0x9c/0x161
> [<ffffffff8108d5f2>] run_ksoftirqd+0x23/0x42
> [<ffffffff810a7ebe>] smpboot_thread_fn+0x253/0x259
> [<ffffffff810a7c6b>] ? test_ti_thread_flag.clone.0+0x11/0x11
> [<ffffffff810a0a6d>] kthread+0xc2/0xca
> [<ffffffff810a09ab>] ? __init_kthread_worker+0x56/0x56
> [<ffffffff81537b7c>] ret_from_fork+0x7c/0xb0
> [<ffffffff810a09ab>] ? __init_kthread_worker+0x56/0x56
## This is from a slightly different kernel image...but probably this part is legit.
0xffffffff814a92b3 is in ip_rcv (/home/greearb/git/linux-3.7.dev.y/net/ipv4/ip_input.c:466).
461 /* Our transport medium may have padded the buffer out. Now we know it
462 * is IP we can trim to the true length of the frame.
463 * Note this now means skb->len holds ntohs(iph->tot_len).
464 */
465 if (pskb_trim_rcsum(skb, len)) {
466 IP_INC_STATS_BH(dev_net(dev), IPSTATS_MIB_INDISCARDS);
467 goto drop;
468 }
469
470 /* Remove any debris in the socket control block */
--
Ben Greear <greearb@candelatech.com>
Candela Technologies Inc http://www.candelatech.com
next prev parent reply other threads:[~2013-01-23 23:55 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-01-21 21:07 3.7.3+: Bad paging request in ip_rcv_finish while running NFS traffic Ben Greear
2013-01-22 0:32 ` Ben Greear
2013-01-22 4:40 ` Eric Dumazet
2013-01-22 5:57 ` Ben Greear
2013-01-22 17:08 ` Ben Greear
2013-01-22 17:17 ` Eric Dumazet
2013-01-22 17:26 ` Ben Greear
2013-01-22 17:26 ` Eric Dumazet
2013-01-22 22:18 ` Ben Greear
2013-01-23 2:32 ` Ben Greear
2013-01-23 6:11 ` Eric Dumazet
2013-01-23 7:14 ` Ben Greear
2013-01-23 13:35 ` Eric Dumazet
2013-01-23 18:15 ` Ben Greear
2013-01-23 21:43 ` Eric Dumazet
2013-01-23 14:42 ` Eric Dumazet
2013-01-23 21:53 ` Ben Greear
2013-01-23 23:55 ` Ben Greear [this message]
2013-01-24 0:01 ` Eric Dumazet
2013-01-24 0:13 ` Ben Greear
2013-01-24 0:23 ` Eric Dumazet
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