From: Daniel Borkmann <borkmann@iogearbox•net>
To: charley.chu@broadcom•com
Cc: netdev@vger•kernel.org
Subject: Fwd: Kernel Oops in __inet_twsk_kill()
Date: Wed, 05 Nov 2014 17:00:52 +0100 [thread overview]
Message-ID: <545A49B4.7090107@iogearbox.net> (raw)
In-Reply-To: <FB8A4655DFD2B34DB16AE06DDDD6C0E231A6F030@SJEXCHMB12.corp.ad.broadcom.com>
[ moving to netdev ]
-------- Original Message --------
Subject: Kernel Oops in __inet_twsk_kill()
Date: Tue, 4 Nov 2014 23:47:18 +0000
From: Charley (Hao Chuan) Chu <charley.chu@broadcom•com>
To: linux-kernel@vger•kernel.org <linux-kernel@vger•kernel.org>
We have situation on our system. It brings the network interface up and down every
a few seconds. Eventually, it brings down the system - the kernel crashed due to BUG
on in __inet_twsk_kill(). The debug message show following call flow.
1) time-wait socket is created by tcp_time_wait() when the socket gets into "TIME_WAIT" state.
inet_twsk_alloc() - refcnt= 0
inet_twsk_hashdance() - refcnt = 3
inet_twsk_schedule() - refcnt = 4
inet_twsk_put() - refcnt = 3
2) tcp_v4_timewait_ack() is called when sync is received
inet_twsk_put() - refcnt= 2 <== where we thing the problem is
occasionally, second sync is received, so the inet_twsk_put is called twice - refcnt = 1
3) twdr_do_twkill_work() is called when timed out
call __inet_twsk_kill - BUG_ON!!! as refcnt=2 (supposed to be 3).
call inet_twsk_put()
In a normal case, the callflow only has step 1 and step 3. Our understanding is
the time-wait socket has three references - ehash, bhash and timer death row. In
step 2, none of them are touched. Can anyone here explain to us why the inet_twsk_put()
is called in tcp_v4_timewait_ack()?
our system has 3.14 kernel.
Any help would be highly appreciated.
Charley Chu
next parent reply other threads:[~2014-11-05 16:22 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <FB8A4655DFD2B34DB16AE06DDDD6C0E231A6F030@SJEXCHMB12.corp.ad.broadcom.com>
2014-11-05 16:00 ` Daniel Borkmann [this message]
2014-11-05 18:00 ` Kernel Oops in __inet_twsk_kill() Cong Wang
2014-11-05 19:16 ` Charley (Hao Chuan) Chu
2014-11-05 19:39 ` David Miller
2014-11-05 20:35 ` Charley (Hao Chuan) Chu
2015-07-10 16:36 ` Phani
2015-08-03 2:19 ` charley
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=545A49B4.7090107@iogearbox.net \
--to=borkmann@iogearbox$(echo .)net \
--cc=charley.chu@broadcom$(echo .)com \
--cc=netdev@vger$(echo .)kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
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