public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: Jason Baron <jbaron@akamai.com>
To: Mathias Krause <minipli@googlemail.com>
Cc: netdev@vger.kernel.org,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	Eric Wong <normalperson@yhbt.net>,
	Eric Dumazet <eric.dumazet@gmail.com>,
	Rainer Weikusat <rweikusat@mobileactivedefense.com>,
	Alexander Viro <viro@zeniv.linux.org.uk>,
	Davide Libenzi <davidel@xmailserver.org>,
	Davidlohr Bueso <dave@stgolabs.net>,
	Olivier Mauras <olivier@mauras.ch>,
	PaX Team <pageexec@freemail.hu>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	"peterz@infradead.org" <peterz@infradead.org>,
	"davem@davemloft.net" <davem@davemloft.net>
Subject: Re: List corruption on epoll_ctl(EPOLL_CTL_DEL) an AF_UNIX socket
Date: Wed, 30 Sep 2015 22:39:58 -0400	[thread overview]
Message-ID: <560C9CFE.6090509@akamai.com> (raw)
In-Reply-To: <CA+rthh9XU+5oN9Ua-+8XPF9Q0y03FZyxds53sxUjsvsJN2kaJA@mail.gmail.com>

On 09/30/2015 01:54 AM, Mathias Krause wrote:
> On 29 September 2015 at 21:09, Jason Baron <jbaron@akamai.com> wrote:
>> However, if we call connect on socket 's', to connect to a new socket 'o2', we
>> drop the reference on the original socket 'o'. Thus, we can now close socket
>> 'o' without unregistering from epoll. Then, when we either close the ep
>> or unregister 'o', we end up with this list corruption. Thus, this is not a
>> race per se, but can be triggered sequentially.
> 
> Sounds profound, but the reproducers calls connect only once per
> socket. So there is no "connect to a new socket", no?
> But w/e, see below.

Yes, but it can be reproduced this way too. It can also happen with a
close() on the remote peer 'o', and a send to 'o' from 's', which the
reproducer can do as pointed out Michal. The patch I sent deals with
both cases.

Thanks,

-Jason

  parent reply	other threads:[~2015-10-01  2:40 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-09-13 19:53 List corruption on epoll_ctl(EPOLL_CTL_DEL) an AF_UNIX socket Mathias Krause
2015-09-14  2:39 ` Eric Wong
2015-09-29 18:09   ` Mathias Krause
2015-09-29 19:09     ` Jason Baron
2015-09-30  5:54       ` Mathias Krause
2015-09-30  7:34         ` Michal Kubecek
2015-10-01  2:55           ` Jason Baron
2015-09-30 10:56         ` Rainer Weikusat
2015-09-30 11:55           ` Mathias Krause
2015-09-30 13:25             ` Rainer Weikusat
2015-09-30 13:38               ` Mathias Krause
2015-09-30 13:51                 ` Rainer Weikusat
2015-10-01  2:39         ` Jason Baron [this message]
2015-10-01 10:33           ` Rainer Weikusat
2015-10-01 12:10             ` Rainer Weikusat
2015-10-01 12:58               ` Rainer Weikusat
2015-09-15 17:07 ` Rainer Weikusat
2015-09-15 18:15   ` Mathias Krause

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=560C9CFE.6090509@akamai.com \
    --to=jbaron@akamai.com \
    --cc=dave@stgolabs.net \
    --cc=davem@davemloft.net \
    --cc=davidel@xmailserver.org \
    --cc=eric.dumazet@gmail.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=minipli@googlemail.com \
    --cc=netdev@vger.kernel.org \
    --cc=normalperson@yhbt.net \
    --cc=olivier@mauras.ch \
    --cc=pageexec@freemail.hu \
    --cc=peterz@infradead.org \
    --cc=rweikusat@mobileactivedefense.com \
    --cc=torvalds@linux-foundation.org \
    --cc=viro@zeniv.linux.org.uk \
    /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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox