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Date: Tue, 29 Sep 2026 09:20:30 +0200
From: Florian Westphal <fw@strlen.de>
To: =?utf-8?B?7ISx67OR7LCs?= <tjdqudcks0424@naver.com>
Cc: netfilter-devel@vger.kernel.org, pablo@netfilter.org, phil@nwl.cc
Subject: Re: [BUG] netfilter: IPv6 conntrack fragment reassembly truncates
 header offset
Message-ID: <artmviCh2h4vYLKG@strlen.de>
References: <622191c6a9b35335b65fdb07f8914b7@cweb016.nm>
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In-Reply-To: <622191c6a9b35335b65fdb07f8914b7@cweb016.nm>

성병찬 <tjdqudcks0424@naver.com> wrote:
> I found a reproducible IPv6 conntrack fragment reassembly bug in:
> 
>   net/ipv6/netfilter/nf_conntrack_reasm.c
> 
> Tested kernel:
> 
>   Linux v7.2.8
>   commit 9a66fdc0d7fd55f54235524a73435af99051e46f
>   x86_64 with KASAN enabled
>
> In find_prev_fhdr(), the previous Next Header offset is stored in u8:
> 
>   u8 prev_nhoff = netoff + offsetof(struct ipv6hdr, nexthdr);

Please send a formal patch, thanks.