netdev - Re: ICMP packets - ll_temac with Microblaze

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: Windows password security audit tool. GUI, reports in PDF.

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

Date:	Wed, 21 Dec 2011 12:13:43 +0100
From:	Eric Dumazet <eric.dumazet@...il.com>
To:	monstr@...str.eu
Cc:	David Miller <davem@...emloft.net>,
	John Williams <john.williams@...alogix.com>,
	netdev@...r.kernel.org
Subject: Re: ICMP packets - ll_temac with Microblaze

Le mercredi 21 décembre 2011 à 12:10 +0100, Michal Simek a écrit :
> Eric Dumazet wrote:
> > Le mercredi 21 décembre 2011 à 11:45 +0100, Eric Dumazet a écrit :
> >> Le mercredi 21 décembre 2011 à 11:41 +0100, Michal Simek a écrit :
> >>
> >>> yes, page size is 4k.
> >>>
> >>> Here is the log for allocation - origin size for MTU 9000 is 0x2420(9248) and size after
> >>> overhead is 0x3f40(16192)
> >>>
> >>> kmalloc_node_track_caller size 00002420, SKB_WITH_OVERHEAD(ksize(data)) 00003f40
> >>> skb->head     c7870000
> >>> skb->data     c7870000
> >>> skb->tail     c7870000
> >>> skb->truesize 000040c0
> >>> skb->end      c7873f40
> >>>
> >> So basically truesize is bigger than previous kernel, and you hit a
> >> socket limit.  (RCVBUF ?)
> >>
> >> truesize is more correct, so we uncover prior bugs.
> >>
> >> We should allow at least one packet, regardless of its size :(
> >>
> >>
> > 
> > I would try the following patch :
> > 
> > diff --git a/include/net/sock.h b/include/net/sock.h
> > index bf6b9fd..21bb3b5 100644
> > --- a/include/net/sock.h
> > +++ b/include/net/sock.h
> > @@ -662,12 +662,14 @@ static inline void __sk_add_backlog(struct sock *sk, struct sk_buff *skb)
> >  
> >  /*
> >   * Take into account size of receive queue and backlog queue
> > + * Do not take into account this skb truesize,
> > + * to allow even a single big packet to come.
> >   */
> >  static inline bool sk_rcvqueues_full(const struct sock *sk, const struct sk_buff *skb)
> >  {
> >  	unsigned int qsize = sk->sk_backlog.len + atomic_read(&sk->sk_rmem_alloc);
> >  
> > -	return qsize + skb->truesize > sk->sk_rcvbuf;
> > +	return qsize > sk->sk_rcvbuf;
> >  }
> >  
> >  /* The per-socket spinlock must be held here. */
> > 
> 
> It doesn't fix the problem. Do you want to add some printk to code?
> 
> Michal
> 
> 
> 

try to change SOCK_MIN_RCVBUF

include/net/sock.h

#define SOCK_MIN_RCVBUF (2048 + sizeof(struct sk_buff))

->

#define SOCK_MIN_RCVBUF (16384 + sizeof(struct sk_buff))



--
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