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From: Florian Westphal <fw@strlen.de>
To: Theodor Arsenij Larionov-Trichkine <theodorlarionov@gmail.com>
Cc: Pablo Neira Ayuso <pablo@netfilter.org>,
	Phil Sutter <phil@nwl.cc>,
	netfilter-devel@vger.kernel.org, coreteam@netfilter.org
Subject: Re: [BUG] netfilter: nft_fib: NULL-ptr-deref (GPF) in nft_fib6_eval on netdev egress hook
Date: Wed, 24 Jun 2026 22:19:23 +0200	[thread overview]
Message-ID: <ajw7y1y7E8yyasOy@strlen.de> (raw)
In-Reply-To: <CAEZyMPC0BQ=FO80mi3BVZaL4=T9y6=MYVL32St=Ck4w53hASqg@mail.gmail.com>

Theodor Arsenij Larionov-Trichkine <theodorlarionov@gmail.com> wrote:
> A `fib' expression in a netdev `egress' base chain dereferences the input
> device nft_in(pkt), which is NULL on the transmit path, so any IPv6 packet
> leaving the chain's device hits a GPF / KASAN NULL-ptr-deref. An unprivileged
> user can set this up in a user+net namespace.

Please just send a patch to disable fib on egress.

  reply	other threads:[~2026-06-24 20:19 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-06-24 19:04 [BUG] netfilter: nft_fib: NULL-ptr-deref (GPF) in nft_fib6_eval on netdev egress hook Theodor Arsenij Larionov-Trichkine
2026-06-24 20:19 ` Florian Westphal [this message]
2026-06-24 22:23   ` Pablo Neira Ayuso
2026-06-24 23:47     ` Florian Westphal
2026-06-25 12:28       ` [PATCH nf] netfilter: nft_fib: reject fib expression on the " Theodor Arsenij Larionov-Trichkine
2026-06-25 20:11         ` Pablo Neira Ayuso
2026-06-29 10:53           ` [PATCH nf v2] " Theodor Arsenij Larionov-Trichkine

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