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Date: Mon, 16 Mar 2026 16:12:47 -0700
From: Jakub Kicinski <kuba@kernel.org>
To: Paul Moses <p@1g4.org>
Cc: davem@davemloft.net, edumazet@google.com, pabeni@redhat.com,
 horms@kernel.org, jiri@resnulli.us, netdev@vger.kernel.org,
 linux-kernel@vger.kernel.org, stable@vger.kernel.org
Subject: Re: [PATCH net 1/2] net-shapers: clear hierarchy pointer and defer
 flush frees with RCU
Message-ID: <20260316161247.1f472be5@kernel.org>
In-Reply-To: <hHYLQqDrBCcK_2x6uSbGsBott3QuXe8o-R9tj4vNmw8UUEFxpzoD_PCMiHMyyOnySAtQbJtCAB8yVoCmWxzO07C02Q5o0J6fHu4NLEa-ggY=@1g4.org>
References: <20260309173450.538026-1-p@1g4.org>
	<20260310192842.3c3b2070@kernel.org>
	<hHYLQqDrBCcK_2x6uSbGsBott3QuXe8o-R9tj4vNmw8UUEFxpzoD_PCMiHMyyOnySAtQbJtCAB8yVoCmWxzO07C02Q5o0J6fHu4NLEa-ggY=@1g4.org>
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On Mon, 16 Mar 2026 18:45:48 +0000 Paul Moses wrote:
> > This is not the right fix. The shaper hierarchy as a while is not under
> > RCU. The problem is that we take a ref on netdev and then lock it,
> > assuming that it's still alive. But it may have gotten unregistered in
> > the meantime. The correct fix is to check that the netdev is still
> > alive after we lock the binding or take RCU from the Netlink side.  
> 
> Ok I see it now, I didn't care about anything except queue because it's the only 
> path that affected both drivers. This is an entirely different issue.

Did you write any of this email or am I just talking to an LLM?