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From:   Xin Long <lucien.xin@gmail.com>
Date:   Thu, 21 May 2020 14:49:07 +0800
Message-ID: <CADvbK_eXW24SkuLUOKkcg4JPa8XLcWpp6RNCrQT+=okaWe+GDA@mail.gmail.com>
Subject: Re: [PATCH v2] xfrm: policy: Fix xfrm policy match
To:     Steffen Klassert <steffen.klassert@secunet.com>
Cc:     Yuehaibing <yuehaibing@huawei.com>,
        Herbert Xu <herbert@gondor.apana.org.au>,
        davem <davem@davemloft.net>, Jakub Kicinski <kuba@kernel.org>,
        network dev <netdev@vger.kernel.org>,
        LKML <linux-kernel@vger.kernel.org>
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On Tue, May 19, 2020 at 4:53 PM Steffen Klassert
<steffen.klassert@secunet.com> wrote:
>
> On Fri, May 15, 2020 at 04:39:57PM +0800, Yuehaibing wrote:
> >
> > Friendly ping...
> >
> > Any plan for this issue?
>
> There was still no consensus between you and Xin on how
> to fix this issue. Once this happens, I consider applying
> a fix.
>
Sorry, Yuehaibing, I can't really accept to do: (A->mark.m & A->mark.v)
I'm thinking to change to:

 static bool xfrm_policy_mark_match(struct xfrm_policy *policy,
                                   struct xfrm_policy *pol)
 {
-       u32 mark = policy->mark.v & policy->mark.m;
-
-       if (policy->mark.v == pol->mark.v && policy->mark.m == pol->mark.m)
-               return true;
-
-       if ((mark & pol->mark.m) == pol->mark.v &&
-           policy->priority == pol->priority)
+       if (policy->mark.v == pol->mark.v &&
+           (policy->mark.m == pol->mark.m ||
+            policy->priority == pol->priority))
                return true;

        return false;

which means we consider (the same value and mask) or
(the same value and priority) as the same one. This will
cover both problems.