From mboxrd@z Thu Jan  1 00:00:00 1970
From: =?ISO-8859-1?Q?Timo_Ter=E4s?= <timo.teras@iki.fi>
Subject: Re: [PATCH 1/7] xfrm: remove policy lock when accessing policy->walk.dead
Date: Tue, 30 Mar 2010 16:33:52 +0300
Message-ID: <4BB1FDC0.5020200@iki.fi>
References: <1269871964-5412-1-git-send-email-timo.teras@iki.fi> <1269871964-5412-2-git-send-email-timo.teras@iki.fi> <20100329144339.GA26214@gondor.apana.org.au> <4BB1842B.9010704@iki.fi> <20100330115351.GA5731@gondor.apana.org.au> <4BB1E8B1.4030604@iki.fi> <20100330121427.GD5731@gondor.apana.org.au> <4BB1ECBF.50000@iki.fi> <20100330122301.GG5731@gondor.apana.org.au> <4BB1F15E.3030402@iki.fi> <20100330124815.GA6378@gondor.apana.org.au>
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To: Herbert Xu <herbert@gondor.apana.org.au>
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Herbert Xu wrote:
> On Tue, Mar 30, 2010 at 03:41:02PM +0300, Timo Ter=E4s wrote:
>> So it'd make more sense to nuke the hashes entirely for
>> per-socket policies?
>=20
> Absolutely.

I checked now the xfrm_user, and mostly it seems to prevent
modification to per-socket policies.

The only exception is XFRM_MSG_POLEXPIRE handler
xfrm_add_pol_expire(). It calls xfrm_policy_byid() without
verifying the direction, and can thus complete successfully on
a per-socket policy. This can actually result in per-socket
policy deletion via netlink.

I guess the proper thing is to add the direction check there.

It also seems that the by-index hash is also used when
generating new index. It's to double check that the index
is unique. So deleting the by-index hash from per-socket
policies seems tricky.

Removing bydst hashing should be trivial.