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Date:   Thu, 22 Oct 2020 17:48:07 +1100
From:   Herbert Xu <herbert@gondor.apana.org.au>
To:     "zhuoliang.zhang" <zhuoliang.zhang@mediatek.com>
Cc:     Steffen Klassert <steffen.klassert@secunet.com>,
        "David S . Miller" <davem@davemloft.net>,
        Jakub Kicinski <kuba@kernel.org>,
        Matthias Brugger <matthias.bgg@gmail.com>,
        netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org,
        linux-mediatek@lists.infradead.org, wsd_upstream@mediatek.com
Subject: Re: [PATCH] net: xfrm: fix a race condition during allocing spi
Message-ID: <20201022064807.GA16043@gondor.apana.org.au>
References: <20201020081800.29454-1-zhuoliang.zhang@mediatek.com>
 <20201021071222.GA11474@gondor.apana.org.au>
 <1603345995.13237.2.camel@mbjsdccf07>
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On Thu, Oct 22, 2020 at 01:53:15PM +0800, zhuoliang.zhang wrote:
> 
> there are 2 related hash lists : net->xfrm.state_bydst and
> net->xfrm.state_byspi:
> 
> 1. a new state x is alloced in xfrm_state_alloc() and added into the
> bydst hlist in  __find_acq_core() on the LHS;
> 2. on the RHS, state_hash_work thread travels the old bydst and tranfers
> every xfrm_state (include x) to the new bydst hlist and new byspi hlist;
> 3. user thread on the LHS gets the lock and adds x to the new byspi
> hlist again.

Good catch.  Please add a Fixes header.  I think this was introduced
with the dynamic resizing in f034b5d4efdfe0fb9e2a1ce1d95fa7914f24de49.

Thanks,
-- 
Email: Herbert Xu <herbert@gondor.apana.org.au>
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