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Date: Wed, 28 May 2025 17:25:07 -0700
From: Jakub Kicinski <kuba@kernel.org>
To: Alexander Lobakin <aleksander.lobakin@intel.com>
Cc: Tony Nguyen <anthony.l.nguyen@intel.com>, <davem@davemloft.net>,
 <pabeni@redhat.com>, <edumazet@google.com>, <andrew+netdev@lunn.ch>,
 <netdev@vger.kernel.org>, <maciej.fijalkowski@intel.com>,
 <magnus.karlsson@intel.com>, <michal.kubiak@intel.com>,
 <przemyslaw.kitszel@intel.com>, <ast@kernel.org>, <daniel@iogearbox.net>,
 <hawk@kernel.org>, <john.fastabend@gmail.com>, <horms@kernel.org>,
 <bpf@vger.kernel.org>, Mina Almasry <almasrymina@google.com>
Subject: Re: [PATCH net-next 01/16] libeth: convert to netmem
Message-ID: <20250528172507.599cce65@kernel.org>
In-Reply-To: <20d9b588-f813-4bad-a4da-e058508322df@intel.com>
References: <20250520205920.2134829-1-anthony.l.nguyen@intel.com>
	<20250520205920.2134829-2-anthony.l.nguyen@intel.com>
	<20250527185749.5053f557@kernel.org>
	<20d9b588-f813-4bad-a4da-e058508322df@intel.com>
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On Wed, 28 May 2025 16:54:39 +0200 Alexander Lobakin wrote:
> > So what happens to the packet that landed in a netmem buffer in case
> > when HDS failed? I don't see the handling.  
> 
> This should not happen in general, as in order to use TCP devmem, you
> need to isolate the traffic, and idpf parses all TCP frames correctly.
> If this condition is true, then napi_build_skb() will be called with the
> devmem buffer passed as head. Should I drop such packets, so that this
> would never happen?

Yes, misrouted packets can't crash the kernel.