netdev.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Florian Westphal <fw@strlen.de>
To: Cong Wang <xiyou.wangcong@gmail.com>
Cc: netfilter-devel@vger.kernel.org,
	Linux Kernel Network Developers <netdev@vger.kernel.org>
Subject: Re: Memory leaks in conntrack
Date: Wed, 13 Sep 2017 10:05:16 +0200	[thread overview]
Message-ID: <20170913080516.GD25977@breakpoint.cc> (raw)
In-Reply-To: <CAM_iQpWvO3L1JOrCMvAvqduWH5pt_9-=GEx+eOFQyOt5Z5prrA@mail.gmail.com>

Cong Wang <xiyou.wangcong@gmail.com> wrote:
> While testing my TC filter patches (so not related to conntrack), the
> following memory leaks are shown up:
> 
> unreferenced object 0xffff9b19ba551228 (size 128):
>   comm "chronyd", pid 338, jiffies 4294910829 (age 53.188s)
>   hex dump (first 32 bytes):
>     6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
>     00 00 00 00 18 00 00 30 00 00 00 00 00 00 00 00  .......0........
>   backtrace:
>     [<ffffffff9f1e1175>] create_object+0x169/0x2aa
>     [<ffffffff9fb77fb2>] kmemleak_alloc+0x25/0x41
>     [<ffffffff9f1c47ed>] slab_post_alloc_hook+0x44/0x65
>     [<ffffffff9f1ca2db>] __kmalloc_track_caller+0x113/0x146
>     [<ffffffff9f193c3b>] __krealloc+0x4a/0x69
>     [<ffffffff9f948dbd>] nf_ct_ext_add+0xe1/0x145
>     [<ffffffff9f942395>] init_conntrack+0x1f7/0x36e
>     [<ffffffff9f942762>] nf_conntrack_in+0x1d3/0x326
>     [<ffffffff9fa1ea69>] ipv4_conntrack_local+0x4d/0x50
>     [<ffffffff9f93ad70>] nf_hook_slow+0x3c/0x9b
>     [<ffffffff9f9c7999>] nf_hook.constprop.40+0xbe/0xd8
>     [<ffffffff9f9c7ba2>] __ip_local_out+0xb3/0xbf
>     [<ffffffff9f9c7bca>] ip_local_out+0x1c/0x36
>     [<ffffffff9f9c9216>] ip_send_skb+0x19/0x3d
>     [<ffffffff9f9ee3de>] udp_send_skb+0x17e/0x1df
>     [<ffffffff9f9eea37>] udp_sendmsg+0x5a2/0x77c
> unreferenced object 0xffff9b19a69b3340 (size 336):
>   comm "chronyd", pid 338, jiffies 4294910868 (age 53.032s)
>   hex dump (first 32 bytes):
>     01 00 00 00 5a 5a 5a 5a 00 00 00 00 ad 4e ad de  ....ZZZZ.....N..
>     ff ff ff ff 5a 5a 5a 5a ff ff ff ff ff ff ff ff  ....ZZZZ........
>   backtrace:
>     [<ffffffff9f1e1175>] create_object+0x169/0x2aa
>     [<ffffffff9fb77fb2>] kmemleak_alloc+0x25/0x41
>     [<ffffffff9f1c47ed>] slab_post_alloc_hook+0x44/0x65
>     [<ffffffff9f1c7a7d>] kmem_cache_alloc+0xd7/0x1f1
>     [<ffffffff9f941b78>] __nf_conntrack_alloc+0xa2/0x146
>     [<ffffffff9f942250>] init_conntrack+0xb2/0x36e
>     [<ffffffff9f942762>] nf_conntrack_in+0x1d3/0x326
>     [<ffffffff9fa1ea69>] ipv4_conntrack_local+0x4d/0x50
>     [<ffffffff9f93ad70>] nf_hook_slow+0x3c/0x9b
>     [<ffffffff9f9c7999>] nf_hook.constprop.40+0xbe/0xd8
>     [<ffffffff9f9c7ba2>] __ip_local_out+0xb3/0xbf
>     [<ffffffff9f9c7bca>] ip_local_out+0x1c/0x36
>     [<ffffffff9f9c9216>] ip_send_skb+0x19/0x3d
>     [<ffffffff9f9ee3de>] udp_send_skb+0x17e/0x1df
>     [<ffffffff9f9eea37>] udp_sendmsg+0x5a2/0x77c
>     [<ffffffff9f9f8cb8>] inet_sendmsg+0x37/0x5e
>
> I don't touch chronyd in my VM, so I have no idea why it sends out UDP
> packets, my guess is it is some periodical packet.
> 
> I don't think I use conntrack either, since /proc/net/ip_conntrack
> does not exist.

You probably do, can you try "cat /proc/net/nf_conntrack" instead?

(otherwise there should be no ipv4_conntrack_local() invocation
 since we would not register this hook at all).

I tried to reproduce this but so far I had no success.
If you can identify something that could give a hint when this
is happening (only once after boot, periodically, only with udp, etc)
please let us know.

(A reproducer would be even better of course ;-) )

Is this with current net tree?

Thanks!

  reply	other threads:[~2017-09-13  8:08 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-09-12 23:20 Memory leaks in conntrack Cong Wang
2017-09-13  8:05 ` Florian Westphal [this message]
2017-09-13 15:37   ` Florian Westphal
2017-09-13 16:45   ` Cong Wang
2017-09-13 17:58     ` Cong Wang

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=20170913080516.GD25977@breakpoint.cc \
    --to=fw@strlen.de \
    --cc=netdev@vger.kernel.org \
    --cc=netfilter-devel@vger.kernel.org \
    --cc=xiyou.wangcong@gmail.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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).