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Date: Wed, 30 Oct 2024 12:49:58 +0100
From: Pablo Neira Ayuso <pablo@netfilter.org>
To: Eric Dumazet <edumazet@google.com>
Cc: "David S . Miller" <davem@davemloft.net>,
	Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
	Jozsef Kadlecsik <kadlec@netfilter.org>, netdev@vger.kernel.org,
	netfilter-devel@vger.kernel.org, coreteam@netfilter.org,
	eric.dumazet@gmail.com, syzbot <syzkaller@googlegroups.com>
Subject: Re: [PATCH nf] netfilter: nf_reject_ipv6: fix potential crash in
 nf_send_reset6()
Message-ID: <ZyIdZlw8Tu2nxJ6l@calendula>
References: <20241025080229.184676-1-edumazet@google.com>
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On Fri, Oct 25, 2024 at 08:02:29AM +0000, Eric Dumazet wrote:
> I got a syzbot report without a repro [1] crashing in nf_send_reset6()
> 
> I think the issue is that dev->hard_header_len is zero, and we attempt
> later to push an Ethernet header.
> 
> Use LL_MAX_HEADER, as other functions in net/ipv6/netfilter/nf_reject_ipv6.c.

Thanks, I will include this in the next PR with netfilter fixes.