netdev - Re: Regression, bisected: reference leak with IPSec since ~2.6.31

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <1285013853.2323.148.camel@edumazet-laptop>
Date:	Mon, 20 Sep 2010 22:17:33 +0200
From:	Eric Dumazet <eric.dumazet@...il.com>
To:	Nick Bowler <nbowler@...iptictech.com>
Cc:	linux-kernel@...r.kernel.org, netdev@...r.kernel.org,
	"David S. Miller" <davem@...emloft.net>
Subject: Re: Regression, bisected: reference leak with IPSec since ~2.6.31

Le lundi 20 septembre 2010 à 15:52 -0400, Nick Bowler a écrit :
> On 2010-09-20 20:20 +0200, Eric Dumazet wrote:
> > If you change your program to send small frames (so they are not
> > fragmented), is the problem still present ?
> 
> I changed MAX_DGRAM_SIZE in the test program to 1000 (mtu on the
> interface is 1500).  The short answer is that the references are
> not leaked, and things seem to get cleaned up.  So the rest of this
> mail probably describes a separate issue.
> 
> The long answer, however, is interesting: With latest Linus' git, the
> references are cleaned up much later than I would expect.  After running
> the test program and flushing the SAD/SPD, the reference count is still
> 1.  If I repeat the test immediately, the reference count will increase
> further.  I can easily raise the reference count to, say, 100.  Now, if
> I wait a while (10 minutes or so), the reference count will still be
> 100.  However, when I run the setkey script after this delay, the
> reference count drops immediately to 1.  If I then flush the SAD/SPD, it
> drops to 0.
> 
> This behaviour is new: newer than the reported leak.  For example, with
> 2.6.34, everything works perfectly with MAX_DGRAM_SIZE set to 1000 (the
> SAs are destroyed immediately when the SAD/SPD are flushed), but the
> leak occurs with MAX_DGRAM_SIZE set to 10000.
> 

Thanks Nick

I suspect a skb->truesize bug somewhere.

I can see atomic_read(&sk->sk_wmem_alloc) becoming negative after a
while...

I am investigating and let you know.

Thanks


--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html