Subject: Re: [PATCH net 1/3] netfilter: nf_conntrack_tcp: re-init for syn packets only

From: Jakub Kicinski <[email-masked]>
Date: Fri, 12 Aug 2022 12:17:19 -0700

On Fri, 12 Aug 2022 09:34:14 -0400 Neal Cardwell wrote:
> This first commit is an important bug fix for a serious bug that causes
> TCP connection hangs for users of TCP fast open and nf_conntrack:
> 
>   c7aab4f17021b netfilter: nf_conntrack_tcp: re-init for syn packets only
> 
> We are continuing to get reports about the bug that this commit fixes.
> 
> It seems this fix was only backported to v5.17 stable release, and not further,
> due to a cherry-pick conflict, because this fix implicitly depends on a
> slightly earlier v5.17 fix in the same spot:
> 
>   82b72cb94666 netfilter: conntrack: re-init state for retransmitted syn-ack
> 
> I manually verified that the fix c7aab4f17021b can be cleanly cherry-picked
> into the oldest (v4.9.325) and newest (v5.15.60) longterm release kernels as
> long as we first cherry-pick that related fix that it implicitly depends on:
> 
> 82b72cb94666b3dbd7152bb9f441b068af7a921b
> netfilter: conntrack: re-init state for retransmitted syn-ack
> 
> c7aab4f17021b636a0ee75bcf28e06fb7c94ab48
> netfilter: nf_conntrack_tcp: re-init for syn packets only
> 
> So would it be possible to backport both of those fixes with the following
> cherry-picks, to all LTS stable releases?
> 
> git cherry-pick 82b72cb94666b3dbd7152bb9f441b068af7a921b
> git cherry-pick c7aab4f17021b636a0ee75bcf28e06fb7c94ab48

Thanks a lot Neal! FWIW we have recently changed our process and no
longer handle stable submissions ourselves, so in the future feel free
to talk directly to stable@ (and add CC: stable@ tags to patches).

I'm adding stable@, let's see if Greg & team can pick things up based
on your instructions :)