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 2A698451996; Thu, 30 Jul 2026 16:19:13 +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=1785428355; cv=none; b=CmqM3FjIrQc0//l8VGzblM5ylhaasBRvHYAZecDTcDok11c+Py/+1aZJhhrOJ8RUiaMEqrX+OsVy1u8QQEzNNhtYEuduMekXn/+3+mBPukW2U7RNLvvjJDkF+DI8r0cdCuE0U+AtGADYjrc0j8ITcDhDHZPVsqB24Mx0HrjHFXo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785428355; c=relaxed/simple; bh=aAbuq0SpajKcVOB0YK8WmMRZX0EfSYzxcp53iccQu64=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ByjJlnh06WViY9MG9qdvTjh0JzXa1CNBXu8jkW0gK6R5PPKo5ar3wpxre1wvG8atoz5JUPvuOOBl9D6M+HhRSc+cLLDPty/DCrITwLWEp0guJ18tPA4NO5stgMAtqSNxV5XvCaLgJVw0BRTnP5Fm5A4CD0CUNn2KlsRokVZ6Jbk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=e4LrcAZJ; 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="e4LrcAZJ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3CF541F000E9; Thu, 30 Jul 2026 16:19:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1785428353; bh=xPd0nHzvQ5DCmNeK99qX1nvtFaeDl+Kb+l47PcTUE5o=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=e4LrcAZJUF/QnarrLtbeIIDUymQe0ws2eKnqdiCeAGwmPRFfEpIoTWa/cu2T7nFPl lQ1i1GWWHng+a8Q2n7TR2clOufu+zCYiLhOSDfPWa3isYmZ+Kth4T//xWdZxcXKdZt /gnKIiuIOWNv/3TOCYaOWrvA0y5D6ZbVrWjNVAts= 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 6.6 463/484] net: ip6_tunnel: require CAP_NET_ADMIN in the device netns for changelink Date: Thu, 30 Jul 2026 16:16:00 +0200 Message-ID: <20260730141433.543668535@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260730141423.392222816@linuxfoundation.org> References: <20260730141423.392222816@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 6.6-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 @@ -2055,6 +2055,9 @@ 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;