Subject: Re: Fw: [Bugme-new] [Bug 8057] New: slab corruption running ip6sic

From: Jarek Poplawski <[email-masked]>
Date: Mon, 12 Mar 2007 11:24:03 +0100

On 22-02-2007 22:49, Andrew Morton wrote:
> 
> Begin forwarded message:
> 
> Date: Thu, 22 Feb 2007 07:56:27 -0800
> From: [email-masked]
> To: [email-masked]
> Subject: [Bugme-new] [Bug 8057] New: slab corruption running ip6sic
> 
> 
> http://bugzilla.kernel.org/show_bug.cgi?id=8057
> 
>            Summary: slab corruption running ip6sic
>     Kernel Version: 2.6.21-rc1
>             Status: NEW
>           Severity: normal
>              Owner: [email-masked]
>          Submitter: [email-masked]
> 
> 
> Most recent kernel where this bug did *NOT* occur: unknown
> Distribution: gentoo
> Hardware Environment: AMD-K6, 400MHz, 288MB Ram
> Software Environment: ip6sic (http://ip6sic.sourceforge.net/)
> Problem Description:
> 
> When running ip6sic against the loopback interface i get the following kernel
> messages:
> 
> [  199.514486] Slab corruption: start=d0505554, len=156
> [  199.514704] Redzone: 0x5a2cf071/0x5a2cf071.
> [  199.514859] Last user: [<c0465813>](kfree_skbmem+0x33/0x80)
...

>>From bugzilla:
...
> Is it possible that the handler frees the skb even if it is not supposed to do so?
> 
> 
> ------- Additional Comment #14 From Eric Sesterhenn 2007-02-28 04:33 -------
> 
> the ipcomp handler is xfrm6_rcv(), which calls xfrm6_rcv_spi(), which contrary
> to all other handlers returns -1 instead of 0 after calling kfree_skb() on the
> skb. Changing the return value to 0 in xfrm6_input.c:xfrm6_rcv_spi() fixes the
> problem.
> But I got no clue at all if this would be a correct fix

I think your diagnose is correct (all "return -1" should be
changed to "return 0" in xfrm6_input.c).

Regards,
Jarek P.