From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A272F221F20; Thu, 5 Mar 2026 01:43:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772675009; cv=none; b=rD3yJt11DOMfitEcAyFyyJJ8Pvs4RWM6FOZvsMWY+HvZajTGrZbBvbRMMGRGaU8tMecKvpwrpAwF1d/sy5pnCzD+GTEZ0/kYaxdFYtrN8wxeXMKI6RSNXXJf+3h/NwVdia6S29V1THL8QUY85ZabJfj4hj0CTHU6BKWkQeRCqDE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772675009; c=relaxed/simple; bh=qtAc2++xWUE/BHhkJWBWqn5Nt2AcxW8aladq0FuhIa0=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=IPucoYvhv/jRHLW0fOR8QbD03vmSwXcOVYUakIX0u1ix/yJoJPd6z93eZ12hdugQU0EACf211qgfLNd9n2VdEFsoI+bYBjYdGpJUgVGqnB7M0Rqujh3LYeUMQZTvBpNx7Qvf+wHDf02UgNKrdSHnte380ZifIzFN/nsMfnZU6+w= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=bHWGdC/F; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="bHWGdC/F" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6AC84C4CEF7; Thu, 5 Mar 2026 01:43:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1772675009; bh=qtAc2++xWUE/BHhkJWBWqn5Nt2AcxW8aladq0FuhIa0=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=bHWGdC/Fx83rdmGIh2eXkMTlouglv7qj45nfIGOvvRkJziDqZeZg6hFoXxabT+JDU JwWrUTlQVDlPdPfFwm0jHeGk8QawSqmpUwkhDfOXvDN6wCAiOa0dC/q+naznpvGZDK 0gIkABUVq5Fzp9HLAZoW4JIDjuv+b/y88mbwYPOQUPgTy6f3dGmJ2gQwLp/92RjINz hofRE6badeJ1UAX5KnzYLQ/AeMJ90ARKaeM24vBPjGklP7gDtlTYq9TqD8W+tYz/py IJPnRC2RnH3ZBPviPaewD+u4CQwfuksa4MMeiucymwnVoEcAMs8sWHGLWEuJNBAOqn fTBev/pnaPsnA== Date: Wed, 4 Mar 2026 17:43:27 -0800 From: Jakub Kicinski To: Daniel Borkmann Cc: Fernando Fernandez Mancera , David Ahern , "Ricardo B. =?UTF-8?B?TWFybGnDqHJl?=" , Martin KaFai Lau , John Fastabend , Stanislav Fomichev , Alexei Starovoitov , Andrii Nakryiko , Eduard Zingerman , Song Liu , Yonghong Song , KP Singh , Hao Luo , Jiri Olsa , "David S. Miller" , Eric Dumazet , Paolo Abeni , Simon Horman , Toke =?UTF-8?B?SMO4?= =?UTF-8?B?aWxhbmQtSsO4cmdlbnNlbg==?= , Jay Vosburgh , Andrew Lunn , Hangbin Liu , bpf@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH net 1/3] bpf: bpf_out_neigh_v4: Fix nd_tbl NULL dereference when IPv6 is disabled Message-ID: <20260304174327.0a48ff45@kernel.org> In-Reply-To: <525dab04-4e64-49cf-94d9-12084e146b80@iogearbox.net> References: <20260228-net-nd_tbl_fixes-v1-0-2b2a274df9bb@suse.com> <20260228-net-nd_tbl_fixes-v1-1-2b2a274df9bb@suse.com> <0b52257d-d557-4f26-9931-34c81ab621bc@iogearbox.net> <20260302171131.28373ccb@kernel.org> <0d7bb5c5-4122-4dc9-b52b-c305591207d1@suse.de> <525dab04-4e64-49cf-94d9-12084e146b80@iogearbox.net> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Thu, 5 Mar 2026 02:34:00 +0100 Daniel Borkmann wrote: > > Maybe I am missing something here, but I believe this won't solve > > the problem. Even if ipv6 is built-in, it should be possible to > > pass ipv6.disable=1 during boot and therefore nd_tbl would still be > > uninitialized, not NULL tho. > > I presume you mean disable_ipv6_mod which then bails out during the module > load process without error, right? It could be deprecated with a warning so > that it turns into a no-op: I believe disabling ipv6 may be legit. Some admins on ipv4 networks may be paranoid and not want to allow any ipv6 traffic if their "firewalls" can only understand IPv6? This is just a guess on my side, but I'm less confident of deprecating the disable knob than =m. I'd be happy if I'm wrong. To answer the earlier question -- I would prefer to take the fixes now and make IPv6 bool in net-next, feels like too big of a change for rc3 :(