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Date: Wed, 22 May 2024 06:55:50 -0700
From: Jakub Kicinski <kuba@kernel.org>
To: Florian Fainelli <f.fainelli@gmail.com>
Cc: Ken Milmore <ken.milmore@gmail.com>, "netdev@vger.kernel.org"
 <netdev@vger.kernel.org>, Heiner Kallweit <hkallweit1@gmail.com>, Realtek
 linux nic maintainers <nic_swsd@realtek.com>, Eric Dumazet
 <edumazet@google.com>
Subject: Re: r8169: Crash with TX segmentation offload on RTL8125
Message-ID: <20240522065550.32d37359@kernel.org>
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On Fri, 17 May 2024 15:21:00 -0700 Florian Fainelli wrote:
> > The patch below fixes the problem, by simply reading nr_frags a bit later, after the checksum stage.  
> 
> Yeah, that's an excellent catch and one that is bitten us before, too:
> 
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=20d1f2d1b024f6be199a3bedf1578a1d21592bc5
> 
> unclear what we would do in skb_shinfo() to help driver writers, rather 
> than rely upon code inspection to find such bugs.

I wonder if we should add a "error injection" hook under DEBUG_NET
to force re-allocation of skbs in any helper which may cause it?