All of lore.kernel.org
 help / color / mirror / Atom feed
From: Eric Dumazet <eric.dumazet@gmail.com>
To: dormando <dormando@rydia.net>
Cc: "Alexey Preobrazhensky" <preobr@google.com>,
	"Steffen Klassert" <steffen.klassert@secunet.com>,
	"David Miller" <davem@davemloft.net>,
	paulmck@linux.vnet.ibm.com, netdev@vger.kernel.org,
	"Kostya Serebryany" <kcc@google.com>,
	"Dmitry Vyukov" <dvyukov@google.com>,
	"Lars Bull" <larsbull@google.com>,
	"Eric Dumazet" <edumazet@google.com>,
	"Bruce Curtis" <brutus@google.com>,
	"Maciej Żenczykowski" <maze@google.com>,
	"Alexei Starovoitov" <alexei.starovoitov@gmail.com>
Subject: Re: [PATCH] ipv4: fix a race in ip4_datagram_release_cb()
Date: Tue, 10 Jun 2014 18:12:53 -0700	[thread overview]
Message-ID: <1402449173.3645.440.camel@edumazet-glaptop2.roam.corp.google.com> (raw)
In-Reply-To: <1402448128.3645.437.camel@edumazet-glaptop2.roam.corp.google.com>

On Tue, 2014-06-10 at 17:55 -0700, Eric Dumazet wrote:
> On Tue, 2014-06-10 at 17:32 -0700, dormando wrote:
> 
> > >
> > 
> > This is neat. So just confirming that I understand (thanks for re-cc'ing
> > me btw <3):
> > 
> > Because of the UDP glitch, it can cause either the kernel panic in the UDP
> > code, but also elsewhere in the TCP stack based on if it's fiddling with
> > the same DST being hosed by a UDP packet?
> > 
> > Unfortunately we're observing a pretty severe sintr cpu increase under
> > 3.14, so I'm going to try this on 3.10.latest. Any potential issues there?
> > 
> > Thankfully it seems like our udpkill utility will reproduce it quickly.
> > Lets see how it goes!
> 
> This is a start, because we have other bugs of the same kind.
> 
> I was working on follow up
> 
> 

For the curious, another problem is in ipv4_sk_update_pmtu()

This can be called on UDP sockets, but from softirq context.

We cannot use sk_dst_lock because this lock is not softirq safe.

I guess we should use xchg() for sk_dst_set() and sk_dst_reset()

  reply	other threads:[~2014-06-11  1:12 UTC|newest]

Thread overview: 41+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-06-06 11:29 Potential race in ip4_datagram_release_cb Alexey Preobrazhensky
2014-06-06 12:56 ` Eric Dumazet
2014-06-06 15:59   ` Alexei Starovoitov
2014-06-06 16:16     ` Eric Dumazet
2014-06-06 17:44       ` Alexei Starovoitov
2014-06-06 17:56         ` Eric Dumazet
2014-06-06 18:13           ` Alexei Starovoitov
2014-06-10 13:43 ` [PATCH] ipv4: fix a race in ip4_datagram_release_cb() Eric Dumazet
2014-06-11  0:32   ` dormando
2014-06-11  0:55     ` Eric Dumazet
2014-06-11  1:12       ` Eric Dumazet [this message]
2014-06-11  1:26         ` Eric Dumazet
2014-06-11  4:16           ` dormando
2014-06-11  5:54             ` Eric Dumazet
2014-06-11  7:20               ` dormando
2014-06-11  7:26                 ` dormando
2014-06-11  7:38                   ` dormando
2014-06-11 12:41                     ` Eric Dumazet
2014-06-11 13:12                       ` Eric Dumazet
2014-06-12  1:55                         ` dormando
2014-06-12  3:43                           ` Eric Dumazet
2014-06-12  4:05                             ` dormando
2014-06-22 19:07                             ` dormando
2014-06-23  8:33                               ` Eric Dumazet
2014-06-23  8:55                                 ` dormando
2014-06-23 16:57                                   ` Dmitry Vyukov
2014-06-24 17:05                                 ` [PATCH net] ipv4: fix dst race in sk_dst_get() Eric Dumazet
2014-06-26  0:42                                   ` David Miller
2014-06-11 13:38             ` [PATCH] ipv4: fix a race in ip4_datagram_release_cb() Kostya Serebryany
2014-06-29  0:25           ` dormando
2014-06-30  6:38             ` Eric Dumazet
2014-06-30  8:15               ` dormando
2014-06-30  8:30                 ` Eric Dumazet
2014-07-08  1:41                   ` dormando
2014-07-08  6:47                     ` Eric Dumazet
2014-07-08  7:01                       ` dormando
2014-07-16 21:03                       ` dormando
2014-07-25  8:11                         ` dormando
2014-06-30  8:26           ` [PATCH] ipv4: irq safe sk_dst_[re]set() and ipv4_sk_update_pmtu() fix Eric Dumazet
2014-07-01  6:43             ` David Miller
2014-06-11 22:39   ` [PATCH] ipv4: fix a race in ip4_datagram_release_cb() David Miller

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=1402449173.3645.440.camel@edumazet-glaptop2.roam.corp.google.com \
    --to=eric.dumazet@gmail.com \
    --cc=alexei.starovoitov@gmail.com \
    --cc=brutus@google.com \
    --cc=davem@davemloft.net \
    --cc=dormando@rydia.net \
    --cc=dvyukov@google.com \
    --cc=edumazet@google.com \
    --cc=kcc@google.com \
    --cc=larsbull@google.com \
    --cc=maze@google.com \
    --cc=netdev@vger.kernel.org \
    --cc=paulmck@linux.vnet.ibm.com \
    --cc=preobr@google.com \
    --cc=steffen.klassert@secunet.com \
    /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.