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From:   Gabriel Ryan <gabe@cs.columbia.edu>
Date:   Mon, 22 Aug 2022 16:51:55 -0400
Message-ID: <CALbthteTSmd9xmBUdBSRzFNMqFemxnba=SnvNgY5KrLYEvpMhQ@mail.gmail.com>
Subject: Re: data-race in nf_tables_newtable / nf_tables_newtable
To:     Florian Westphal <fw@strlen.de>
Cc:     Abhishek Shah <abhishek.shah@columbia.edu>, coreteam@netfilter.org,
        davem@davemloft.net, edumazet@google.com, kadlec@netfilter.org,
        kuba@kernel.org, netdev@vger.kernel.org,
        netfilter-devel@vger.kernel.org, pabeni@redhat.com,
        pablo@netfilter.org, linux-kernel@vger.kernel.org
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Ok, glad everything worked out then, thanks for sharing!

Best,

Gabe

On Mon, Aug 22, 2022 at 4:42 PM Florian Westphal <fw@strlen.de> wrote:
>
> Gabriel Ryan <gabe@cs.columbia.edu> wrote:
> > Hi Florian,
> >
> > I just looked at the lock event trace from our report and it looks
> > like two distinct commit mutexes were held when the race was
> > triggered. I think the race is probably on the table_handle variable
> > on net/netfilter/nf_tables_api.c:1221, and not the table->handle field
> > being written to.
>
> See
>
> https://urldefense.proofpoint.com/v2/url?u=3Dhttps-3A__patchwork.ozlabs.o=
rg_project_netfilter-2Ddevel_patch_20220821085939.571378-2D1-2Dpablo-40netf=
ilter.org_&d=3DDwIFAg&c=3D009klHSCxuh5AI1vNQzSO0KGjl4nbi2Q0M1QLJX9BeE&r=3DE=
yAJYRJu01oaAhhVVY3o8zKgZvacDAXd_PNRtaqACCo&m=3DtKybb4B0md9Rrb5d9AH-UN2fjr4L=
8y6LtRxywepWhKsWCyN0OWaRwAtDbGt10WQD&s=3DuJ4BtOvCcZOe6F17rDKQipDF0McLeOwaUL=
9jO3BgTCU&e=3D
>
> which makes table_handle per netns.