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 5232D409114; Thu, 30 Jul 2026 15:53:58 +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=1785426839; cv=none; b=UHbrty7mWHY4sjGprj17QVKqFMkTJTW1G+PXv5RKrD3vA++qLPGobnWpLHF753uMt5wRZnUZHMl8h7B2cZim02zB0El8ZChOIK195vBbc++GcR0GTas19SscoY3pRLUIjoAfidRGqJgI7qRM+rwLYB4ZxAPwY7HNk8gUn3EYOUU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785426839; c=relaxed/simple; bh=bEzKKjA4VfKsFoh9dGcDEB8kC+vLabPmJYLalOTAucc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=tpgl/u+Wzp2SZgXNsblw3Yj+8s3HpGfi9HM64LNAyhJPXXhDHw+zviW1AZspF0DOjDfBHjX6wwieqhpIyF8G2AqAINjjmTIMd4tYYOOJZ9lxkQb5joVP+F+D5z3upuoUSGdcdiNxXm0qmdEs1g1tUj3exwSwHywaYS7v9tfjiXY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=boVimt8/; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="boVimt8/" Received: by smtp.kernel.org (Postfix) with ESMTPSA id AF9DA1F000E9; Thu, 30 Jul 2026 15:53:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1785426838; bh=F0WQLg2moDsmHnqoi4s30B2sHn5lw1JpxOrfKFHwlDg=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=boVimt8/+ozrvdd31GrjKBNr7Po+FzHe7OGbduReYDt5Ef1AGDRg3jEjMwTaK4Jp3 4hlBf112RDfVQI8rR+JkwtKMgJY/GV3Iu4fXY6MDDuvoo8+rj1o9tWeblOAuv8mJ0w e+weQNKalTL5hqgEHoWa1npkjiO4lymCCyKdvkA0= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Xiao Liang , Maoyi Xie , Kuniyuki Iwashima , Jakub Kicinski , Sasha Levin Subject: [PATCH 6.12 558/602] net: ip6_tunnel: require CAP_NET_ADMIN in the device netns for changelink Date: Thu, 30 Jul 2026 16:15:50 +0200 Message-ID: <20260730141447.766451717@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260730141435.976815864@linuxfoundation.org> References: <20260730141435.976815864@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Maoyi Xie [ Upstream commit 2496fa0b7d180b3ad356b514e7ff93bb14e6140a ] ip6_tnl_changelink() operates on at most two netns, dev_net(dev) and the tunnel link netns t->net. They differ once the device is created in or moved to a netns other than the one the request runs in. The rtnl changelink path checks CAP_NET_ADMIN only against dev_net(dev), so a caller privileged there but not in t->net can rewrite a tunnel that lives in t->net. Gate ip6_tnl_changelink() on rtnl_dev_link_net_capable() at its top, before any attribute is parsed. Reported-by: Xiao Liang Closes: https://lore.kernel.org/netdev/CABAhCOSzP1vaThGV35_VnsRCb=87_CPjPVsTHbq905k8A+BuUg@mail.gmail.com/ Fixes: 0bd8762824e7 ("ip6tnl: add x-netns support") Cc: stable@vger.kernel.org Signed-off-by: Maoyi Xie Reviewed-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20260612085941.3158249-5-maoyixie.tju@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- net/ipv6/ip6_tunnel.c | 3 +++ 1 file changed, 3 insertions(+) --- a/net/ipv6/ip6_tunnel.c +++ b/net/ipv6/ip6_tunnel.c @@ -2053,6 +2053,9 @@ static int ip6_tnl_changelink(struct net struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); struct ip_tunnel_encap ipencap; + if (!rtnl_dev_link_net_capable(dev, net)) + return -EPERM; + if (dev == ip6n->fb_tnl_dev) return -EINVAL;