From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 AF15C419303; Mon, 13 Jul 2026 13:12:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783948343; cv=none; b=gClTwnClLiZLhIOSwN5kuc92Sbkv8C9/urxA9xIrs8i7C0Fcw1EgsjyfZJJoNit0KRd1tmE37sSM1iN3hL/KkGHYWJc2+jzcHvJxJ3kdJw8mesSP4KYi09h9rRB1CNvCgIk3nlH5XC+MhuV4t2lOB9Agj0b9zl/qLMiUBcJIws8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783948343; c=relaxed/simple; bh=w5RxZXMVEYANqtOlQqqY97QF8fW+CMXXCf45JaqfUIU=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=U0bGhwyWtcWTKi7fu2GN5f2R562108260hark7hX3TKS92fa4PG6heBtXyAIdyryV4tDae7gUKtjSEJ4T2zuUYKOb6IyJ7m2gSgRefkftQCpDU1CVcsjQKT+9KiEXQzFEtbcwuSKRmMnmhXhSatT/gSbveV2f09mPS3Eg8QioA4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=A5976fmX; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="A5976fmX" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B124A1F000E9; Mon, 13 Jul 2026 13:12:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1783948342; bh=yrHgwT9ZQSGf+NVPUAnehfl7ebx4MKMj541Yhxfc8Y4=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=A5976fmXoYPItXNoPXhKwpkwS1wvQbGrwjMGNuw26bH095SURG05vry9TY9oJGuKc q7yegn/8zUDuXGUEG5Z2IX5YiQII1zjVPY4A5Q6dnWjneq7q3CzaTGzEzKZLOfFBDp pyX0pFlK/+DlTHG090DL6hY7OGBZSoCCW9PyoqtjdkEy7i9F4SuQU8rzae4x2AFqSg YF7ie5DwuoBxUMjlXqhZFIQCXR7iCb1sznEPCgMi/odi+GqFLm7OntlIJQZjA+QZig 0xGGhAHFViIaL+mVvxmRaZG3jz9MOGQ5gkWAgtqXcENQrzP27DrrfKOB60Fp3hxIr4 ZTWGVPcMhTCwQ== Date: Mon, 13 Jul 2026 14:12:18 +0100 From: Simon Horman To: Ricardo =?utf-8?B?Qi4gTWFybGnDqHJl?= Cc: "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Shuah Khan , Xu Du , netdev@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH net] selftests/net: Fix tun IPv6 test addresses to avoid 6to4 range Message-ID: <20260713131218.GE1364329@horms.kernel.org> References: <20260706-b4-net_tun_addr-v1-1-3d3cb2473560@suse.com> 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=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20260706-b4-net_tun_addr-v1-1-3d3cb2473560@suse.com> On Mon, Jul 06, 2026 at 01:24:04PM -0300, Ricardo B. Marlière wrote: > The IPv6 addresses used for the tun_vnet_udptnl fixture currently fall in > the 2002::/16 prefix, which is reserved for the 6to4 transition mechanism > (RFC 3056). > > On systems where the sit module is loaded, the kernel automatically claims > 2002::/16 as a 6to4 tunnel prefix. When the test assigns a 2002:: address > to a TUN interface, sit registers a competing local route for the same > address. This ambiguity breaks the GENEVE decapsulation path: packets > injected via the TUN fd are not delivered to the test socket, causing the > IPv6-outer gtgso send_gso_packet variants to fail. > > Replace all four IPv6 test addresses with addresses from the fd00:db8::/32 > range, which is part of the ULA space (fc00::/7, RFC 4193) and carries no > special kernel semantics. > > Fixes: 24e59f26eef2 ("selftest: tun: Add helpers for GSO over UDP tunnel") > Signed-off-by: Ricardo B. Marlière Reviewed-by: Simon Horman