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Date:   Tue, 12 Sep 2023 11:40:38 -0400
From:   Jeremy Cline <jeremy@jcline.org>
To:     Simon Horman <horms@kernel.org>
Cc:     Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>,
        "David S . Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org,
        syzbot+c1d0a03d305972dbbe14@syzkaller.appspotmail.com
Subject: Re: [PATCH net] net: nfc: llcp: Add lock when modifying device list
Message-ID: <ZQCGduvxodv4QQD7@dev>
References: <20230908235853.1319596-1-jeremy@jcline.org>
 <20230910152812.GJ775887@kernel.org>
 <ZP5L6/zF6fE+ogbz@dev>
 <20230911055904.GN775887@kernel.org>
 <20230911125251.GA23672@kernel.org>
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On Mon, Sep 11, 2023 at 02:52:51PM +0200, Simon Horman wrote:
> On Mon, Sep 11, 2023 at 07:59:04AM +0200, Simon Horman wrote:
> > On Sun, Sep 10, 2023 at 07:06:19PM -0400, Jeremy Cline wrote:
> > > On Sun, Sep 10, 2023 at 05:28:12PM +0200, Simon Horman wrote:
> > > > On Fri, Sep 08, 2023 at 07:58:53PM -0400, Jeremy Cline wrote:
> > > > > The device list needs its associated lock held when modifying it, or the
> > > > > list could become corrupted, as syzbot discovered.
> > > > > 
> > > > > Reported-and-tested-by: syzbot+c1d0a03d305972dbbe14@syzkaller.appspotmail.com
> > > > > Closes: https://syzkaller.appspot.com/bug?extid=c1d0a03d305972dbbe14
> > > > > Signed-off-by: Jeremy Cline <jeremy@jcline.org>
> > > > 
> > > > Hi Jeremy,
> > > > 
> > > > thanks for your patch.
> > > > 
> > > > I don't think you need to resubmit for this,
> > > > I think this patch warrants a fixes tag:
> > > > 
> > > > Fixes: d646960f7986 ("NFC: Initial LLCP support")
> > > > 
> > > 
> > > My bad, indeed. The lock in question looks to have been added in
> > > 6709d4b7bc2e ("net: nfc: Fix use-after-free caused by
> > > nfc_llcp_find_local") which itself includes a couple fix tags, should
> > > this reference that commit instead as it won't backport without that
> > > one?
> > 
> > Yes, I think that is likely.
> > Sorry for not noticing that.
> 
> And further, sorry for being vague in my previous email.
> Having now looked over 6709d4b7bc2e I agree it is
> the correct commit for a fixes tag for this patch.
> 

Super, thanks. If it's helpful I can re-roll the patch, otherwise I'll
just leave it as-is.

Thanks,
Jeremy