From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from stravinsky.debian.org (stravinsky.debian.org [82.195.75.108]) (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 03D653D669D; Tue, 2 Jun 2026 12:24:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=82.195.75.108 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780403069; cv=none; b=eO9MuHHLyoKhlY8IWWgWQaRVmcZ8ZvIlK4/XwbfovCFOwjKn6pNRFKMobjSjZvtf6j6Sadmy6nk5wCdVanMF8dSWhLjzrBT4f2gnR4b4A+rbt24NGhjy1GrxDs4jYpS7DtRHUvYarTmJ53XW5LgAupBuudMheW6ihwjrJiJOrk0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780403069; c=relaxed/simple; bh=JlT+cZYsqRG96W04CugaFUAuiXRhWUqpRZ1gwj1v9yQ=; h=Message-ID:Subject:From:To:Cc:Date:In-Reply-To:References: Content-Type:MIME-Version; b=iGsz4HzaDCFq7lSPflpN7JRn4y1eMWTBgE9z2G9oyzqBU/Si1dtlnAAaKIoWG5VDiH+OHiWZxaDP9xPMXdiUVlE+T2dI+MCcJqnsq9ehLpslOVC83JJv1DXPem/MhNCJCqG/6vdVct3REvFQmc53Id5on0I+td/yyrVgiSJqY3Q= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=debian.org; spf=pass smtp.mailfrom=debian.org; dkim=pass (2048-bit key) header.d=debian.org header.i=@debian.org header.b=lSBGcYcw; arc=none smtp.client-ip=82.195.75.108 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=debian.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=debian.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=debian.org header.i=@debian.org header.b="lSBGcYcw" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=debian.org; s=smtpauto.stravinsky; h=X-Debian-User:MIME-Version:Content-Type:References: In-Reply-To:Date:Cc:To:From:Subject:Message-ID:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=KVqA0dyDMlZqpwtMJ9x40FOgRbN07P0B63/VMtUhQro=; b=lSBGcYcwI1Kbe1cfXa/27rifmo scx63GB4xXpDCQloMYUD4NJ8Rv87w6TP1+1Le+SqqmHnKBMV+6NrT9f0Jr5+ViLcLQZOKlS42FT9q ydf6rDB3xDcEhZ1DR5STEbOACE4IyA+U9nheEjVC7534M6qCFs4RvcTFHi8g8wgXDE5LpbKPmmRME jastH441b9qUFise3AOStU/6SX0yEgO9r7Xzx/yuWP8A+qZFEwjAVNkMNM17RWc0phKa2HtxK9HDa 6utSlaudiPL0dx/rOyuHHQyTKvNUpebC6y/eNjiSblOD+ZEfJD1JAwSKumGtlFFStiFwRkTYBu52B 4dd69Y2A==; Received: from authenticated-user by stravinsky.debian.org with esmtpsa (TLS1.3:ECDHE_SECP256R1__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim 4.96) (envelope-from ) id 1wUOAK-002x2t-2P; Tue, 02 Jun 2026 12:24:16 +0000 Message-ID: Subject: Re: [PATCH 5.15 002/570] ip6_tunnel: Fix usage of skb_vlan_inet_prepare() From: Ben Hutchings To: Harshit Mogalapalli , Greg Kroah-Hartman , stable@vger.kernel.org Cc: patches@lists.linux.dev, Sasha Levin , Alexandr Alexandrov Date: Tue, 02 Jun 2026 14:24:10 +0200 In-Reply-To: <68ad88bb-958d-4009-8631-284853ffe1b0@oracle.com> References: <20260413155830.386096114@linuxfoundation.org> <20260413155830.485087556@linuxfoundation.org> <68ad88bb-958d-4009-8631-284853ffe1b0@oracle.com> Organization: Debian Content-Type: multipart/signed; micalg="pgp-sha512"; protocol="application/pgp-signature"; boundary="=-GEeodVjEnDPZLD35272B" User-Agent: Evolution 3.56.2-9 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Debian-User: benh --=-GEeodVjEnDPZLD35272B Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Tue, 2026-06-02 at 16:50 +0530, Harshit Mogalapalli wrote: > Hi Ben, Greg, Sasha, >=20 > On 13/04/26 21:22, Greg Kroah-Hartman wrote: > > 5.15-stable review patch. If anyone has any objections, please let me = know. > >=20 > > ------------------ > >=20 > > From: Ben Hutchings > >=20 > > Backports of commit 81c734dae203 "ip6_tunnel: use > > skb_vlan_inet_prepare() in __ip6_tnl_rcv()" broke IPv6 tunnelling in > > stable branches 5.10-6.12 inclusive. This is because the return value > > of skb_vlan_inet_prepare() had the opposite sense (0 for error rather > > than for success) before commit 9990ddf47d416 "net: tunnel: make > > skb_vlan_inet_prepare() return drop reasons". > >=20 > > For branches including commit c504e5c2f964 "net: skb: introduce > > kfree_skb_reason()" etc. (i.e. 6.1 and newer) it was simple to > > backport commit 9990ddf47d416, but for 5.10 and 5.15 that doesn't seem > > to be practical. >=20 > We have seen ltp-net failing after this LTS update on downstream kernel(U= EK) >=20 > mainline : v5.17-rc1 - c504e5c2f964 net: skb:=20 > introduce kfree_skb_reason() > stable-5.15 : v5.15.58 - 5158e18225c0 net: skb:=20 > introduce kfree_skb_reason() >=20 > So this is not needed for 5.15.y. I don't know about that test failure, but your analysis is wrong. The dependency of the original fix was commit 9990ddf47d416 "net: tunnel: make skb_vlan_inet_prepare() return drop reasons" which changed the sense of skb_vlan_inet_prepare()'s return value and has not been backported to 5.15. That in turn depended on the commit you are looking at. > This needs to be reverted for 5.15.y, looks good for 5.10.y [...] I started looking at how to fix the regression in 5.10, which does not have a backport of commit c504e5c2f964, and did not notice that it had been backported to 5.15. So this patch probably could be reverted and replaced with a backport of commit 9990ddf47d416. But simply reverting it would not be correct. Ben. --=20 Ben Hutchings - Debian developer, member of kernel, installer and LTS teams --=-GEeodVjEnDPZLD35272B Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEErCspvTSmr92z9o8157/I7JWGEQkFAmoey2oACgkQ57/I7JWG EQlkURAAtcN3wwN/IwXVolorxWiAfyc16MmuRFvwqC8TRrus+Nc6t19KRRKBscxV 7bFA7bFHNhXnyM4kj2CJEe2Ft4uLwqV66fGnD9K4Kri2nL8Ogc3nYNRl/W7LR2Zg Lw4z1Sk7NUdy2uJ2AYtovuoErzvUPwS1iT/KgcAbFNAl6O6ZrQ1lakOGGXiYwTqG XiBdZL5y3SuT4sEBFf0Pc1lq3Hu7gYVr6gbJybnF264he7dOXTVXYKISFO4icK2J tAPeBHtWQyJUZSCp5mo2HtWHKcBleR1kW3R/hb3CFS4idXw9Hiy/U0scJz7keyRx ByMHnqm42Jpb/mHK7mQ1CPutSi4fztS9+u0GWG775WvHxIPdL52Q31ob6el4q/Vx DypIy3BUDDDZ9t/6zkY8eUk3RYcs+42axPOPoqUTYqkvXOrpusPOy9hySqpIuiZb bVaN21um2AKJIfZhewjKfAizFBiL9W79lEkyn0e4leCu/Nmv0yPL8ylbRfXF93Jx ib1r4GmtiAwjI7VIQKhkoGJE/jdssFwhp2kWmR3563OjpLpU0psWQpNkxTjFQ+MQ YPTpBNquvf8qn42aRWnWE2UGjj0OF+uNAmBrkVl693KO2+cGP/RtgZDd8Ua9hjv5 jnIbPFkKO4GpPj/HubL7Cs6apVdLhCSLI1Mk1koqu1ugYs9ZYJY= =/TEW -----END PGP SIGNATURE----- --=-GEeodVjEnDPZLD35272B--