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Date: Wed, 17 Apr 2024 19:04:32 -0700
From: Jakub Kicinski <kuba@kernel.org>
To: Kuniyuki Iwashima <kuniyu@amazon.com>
Cc: "David S. Miller" <davem@davemloft.net>, Eric Dumazet
 <edumazet@google.com>, Paolo Abeni <pabeni@redhat.com>, David Ahern
 <dsahern@kernel.org>, Steffen Klassert <steffen.klassert@secunet.com>,
 Herbert Xu <herbert@gondor.apana.org.au>, Willem de Bruijn
 <willemb@google.com>, Kuniyuki Iwashima <kuni1840@gmail.com>,
 <netdev@vger.kernel.org>, syzkaller <syzkaller@googlegroups.com>
Subject: Re: [PATCH v1 net 1/5] sit: Pull header after checking
 skb->protocol in sit_tunnel_xmit().
Message-ID: <20240417190432.5d9dc732@kernel.org>
In-Reply-To: <20240415222041.18537-2-kuniyu@amazon.com>
References: <20240415222041.18537-1-kuniyu@amazon.com>
	<20240415222041.18537-2-kuniyu@amazon.com>
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On Mon, 15 Apr 2024 15:20:37 -0700 Kuniyuki Iwashima wrote:
> syzkaller crafted a GSO packet of ETH_P_8021AD + ETH_P_NSH and sent it
> over sit0.
> 
> After nsh_gso_segment(), skb->data - skb->head was 138, on the other
> hand, skb->network_header was 128.

is data offset > skb->network_header valid at this stage?
Can't we drop these packets instead?