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From: Denis Arefev <arefev@swemel.ru>
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To: kuba@kernel.org
Cc: arefev@swemel.ru,
	davem@davemloft.net,
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Subject: [PATCH net] virtio: fix GSO with frames unaligned to size
Date: Thu, 25 Jul 2024 12:22:03 +0300
Message-Id: <20240725092203.26366-1-arefev@swemel.ru>
In-Reply-To: <20240723223109.2196886-1-kuba@kernel.org>
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I checked the patch on three reproducers and all three DEFINITELY broke the core.

There are two malfunctions.

1. No flag skb_shinfo(skb)->tx_flags |= SKBFL_SHARED_FRAG;
 If it is not set then __skb_linearize will not be executed in skb_checksum_help.
 sk_buff remains fragmented (non-linear) and this is the first warning.
 OR add skb_shinfo(skb)->tx_flags |= SKBFL_SHARED_FRAG.
 OR ask Eric Dumazet (cef401de7be8c). Is checking if (skb_has_shared_frag(skb)) so important?
 in the skb_checksum_help function, is it enough if (skb_is_nonlinear(skb)) ?

2. The skb_segment algorithm and related checks, this is where you need time to think ...

Best regards Denis.