Re: [PATCH v4] xfrm: Fix kernel panic when flush and dump SPD entries

[David Miller <davem@davemloft.net>]

From: Herbert Xu <herbert@gondor.apana.org.au>
Date: Mon, 1 Dec 2008 16:11:11 +0800

> On Mon, Dec 01, 2008 at 03:50:54PM +0800, Wei Yongjun wrote:
> > After flush the SPD entries, dump the SPD entries will cause kernel painc.
> > 
> > Used the following commands to reproduct:
> > 
> > - echo 'spdflush;' | setkey -c
> > - echo 'spdadd 3ffe:501:ffff:ff01::/64 3ffe:501:ffff:ff04::/64  any -P out ipsec \
> >   ah/tunnel/3ffe:501:ffff:ff00:200:ff:fe00:b0b0-3ffe:501:ffff:ff02:200:ff:fe00:a1a1/require;\
> >   spddump;' | setkey -c
> > - echo 'spdflush; spddump;' | setkey -c
> > - echo 'spdadd 3ffe:501:ffff:ff01::/64 3ffe:501:ffff:ff04::/64  any -P out ipsec \
> >   ah/tunnel/3ffe:501:ffff:ff00:200:ff:fe00:b0b0-3ffe:501:ffff:ff02:200:ff:fe00:a1a1/require;\
> >   spddump;' | setkey -c
> > 
> > This is because when flush the SPD entries, the SPD entry is not remove
> > from the list.
> > 
> > This patch fix the problem by remove the SPD entry from the list. And
> > also do clean up of remove SPD entry.
> 
> I like the clean-up but it's best if you separate the two changes
> into two patches.  That way it's easy to see exactly what the bug
> fix patch is trying to fix and to verify that the clean-up patch
> really doesn't change behaviour.

Agreed.  Wei, please do this.