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 0885A42B309 for ; Thu, 2 Jul 2026 08:28:23 +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=1782980905; cv=none; b=jwpm+XiwluPYwSnTUt5YopIY8g7dvrhFC/wxOx1RlAi0Q+QihO+nSQHgmL87gcyB/vpNpmDaJVyioplhO2KdCmoGRAgVHkyGedzVOZDmRxikkOya9ambR/1vDRL651/m0f1q5vKoUFaiNMmEoyD/c3sciX9NeRrahCsmNL3fTNg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782980905; c=relaxed/simple; bh=E/bWaJ+Zxtahb9IMbUcSYWh5B6sPKGVLbPJR3L6z07E=; h=Subject:To:Cc:From:Date:Message-ID:MIME-Version:Content-Type; b=f45oeyr4XEKWOqVFy0Ml6r2C9W+AfmHq8AmDdj634MMyy7/SMo9q08VJMW+r85ACUamEiUAKlnmTin6jBQN1DMyPTe3mwieL4FFA5c6Zc+40PwSnyRPEet9jtmmhBWo/f+KgyWWOZqZAy3Tp49a4qKH8GLuGtBT8Ie2Lf5NvtTM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Zxx3tzCc; 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="Zxx3tzCc" Received: by smtp.kernel.org (Postfix) with ESMTPSA id BE5971F00A3A; Thu, 2 Jul 2026 08:28:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1782980903; bh=DpsV2FnfK94qWmlXshyFaGlL9RCQE4AU9IyaMhyQItM=; h=Subject:To:Cc:From:Date; b=Zxx3tzCc50FuZwbY12aS2NmXNnsrMBfGnNcj811GG9kGVgUlraEzv5CnaPqco9XI5 wac88D3ndSv4HlkVWS4TmI1XWnPEvaXhStaxPu+lFA9OVRWEdy1yR6XdNA1RDLXHgu ZGMxEJqV8NZLhzDeqkNJohGV6Bsy6KEezx9EdpTI= Subject: FAILED: patch "[PATCH] net: ip_gre: require CAP_NET_ADMIN in the device netns for" failed to apply to 6.6-stable tree To: maoyixie.tju@gmail.com,kuba@kernel.org,kuniyu@google.com,shaw.leon@gmail.com Cc: From: Date: Thu, 02 Jul 2026 10:28:21 +0200 Message-ID: <2026070221-liberty-skimpily-9ea5@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit The patch below does not apply to the 6.6-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y git checkout FETCH_HEAD git cherry-pick -x 8165f7ff57d9667d2bb477ef6af83ede7fed4ad7 # git commit -s git send-email --to '' --in-reply-to '2026070221-liberty-skimpily-9ea5@gregkh' --subject-prefix 'PATCH 6.6.y' 'HEAD^..' Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 8165f7ff57d9667d2bb477ef6af83ede7fed4ad7 Mon Sep 17 00:00:00 2001 From: Maoyi Xie Date: Fri, 12 Jun 2026 16:59:35 +0800 Subject: [PATCH] net: ip_gre: require CAP_NET_ADMIN in the device netns for changelink A tunnel 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. Add rtnl_dev_link_net_capable() next to rtnl_get_net_ns_capable() in net/core/rtnetlink.c. It requires CAP_NET_ADMIN in the link netns and is skipped when the link netns is dev_net(dev), where the rtnl path already checked it. The other patches in this series use the same helper. Gate ipgre_changelink() and erspan_changelink() with it, at the top of the op before any attribute is parsed, because the parsers update live tunnel fields first. ipgre_netlink_parms() sets t->collect_md before ip_tunnel_changelink() runs. Commit 8b484efd5cb4 ("ip6: vti: Use ip6_tnl.net in vti6_siocdevprivate().") added the same check on the ioctl path. This adds it on RTM_NEWLINK. Reported-by: Xiao Liang Closes: https://lore.kernel.org/netdev/CABAhCOSzP1vaThGV35_VnsRCb=87_CPjPVsTHbq905k8A+BuUg@mail.gmail.com/ Fixes: b57708add314 ("gre: add x-netns support") Cc: stable@vger.kernel.org Signed-off-by: Maoyi Xie Reviewed-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20260612085941.3158249-2-maoyixie.tju@gmail.com Signed-off-by: Jakub Kicinski diff --git a/include/net/rtnetlink.h b/include/net/rtnetlink.h index ec65a8cebb99..2bff41aacc98 100644 --- a/include/net/rtnetlink.h +++ b/include/net/rtnetlink.h @@ -256,6 +256,8 @@ int rtnl_configure_link(struct net_device *dev, const struct ifinfomsg *ifm, int rtnl_nla_parse_ifinfomsg(struct nlattr **tb, const struct nlattr *nla_peer, struct netlink_ext_ack *exterr); struct net *rtnl_get_net_ns_capable(struct sock *sk, int netnsid); +bool rtnl_dev_link_net_capable(const struct net_device *dev, + const struct net *link_net); #define MODULE_ALIAS_RTNL_LINK(kind) MODULE_ALIAS("rtnl-link-" kind) diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index 61d095ce1b3b..12aa3aa1688b 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -2438,6 +2438,14 @@ struct net *rtnl_get_net_ns_capable(struct sock *sk, int netnsid) } EXPORT_SYMBOL_GPL(rtnl_get_net_ns_capable); +bool rtnl_dev_link_net_capable(const struct net_device *dev, + const struct net *link_net) +{ + return net_eq(link_net, dev_net(dev)) || + ns_capable(link_net->user_ns, CAP_NET_ADMIN); +} +EXPORT_SYMBOL_GPL(rtnl_dev_link_net_capable); + static int rtnl_valid_dump_ifinfo_req(const struct nlmsghdr *nlh, bool strict_check, struct nlattr **tb, struct netlink_ext_ack *extack) diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c index 208dd48012d9..3efdfb4ffa21 100644 --- a/net/ipv4/ip_gre.c +++ b/net/ipv4/ip_gre.c @@ -1457,6 +1457,9 @@ static int ipgre_changelink(struct net_device *dev, struct nlattr *tb[], __u32 fwmark = t->fwmark; int err; + if (!rtnl_dev_link_net_capable(dev, t->net)) + return -EPERM; + err = ipgre_newlink_encap_setup(dev, data); if (err) return err; @@ -1486,6 +1489,9 @@ static int erspan_changelink(struct net_device *dev, struct nlattr *tb[], __u32 fwmark = t->fwmark; int err; + if (!rtnl_dev_link_net_capable(dev, t->net)) + return -EPERM; + err = ipgre_newlink_encap_setup(dev, data); if (err) return err;