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 ECD4C42FCDF for ; Tue, 28 Jul 2026 12:11:19 +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=1785240681; cv=none; b=D66kg6R8uP8HXJGINM5xmkEkojfONmHO+ZMd992bh9Ybp2Q4LjWKlqA+hQYe3Ha46eUiK306YJTT6Gvlcal0VXYFnjGyI/8Nmn3l6mpC23JF4S2UH0QpLNNnMKaMLJ1VUoTW89Ubma7ZM2koDVkFhovM5KFRMrSjs9AYA7mBlio= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785240681; c=relaxed/simple; bh=PyFm6IReYBg1THXaXLm4DqSrxy4wTK7TUT6CDBOV5Hg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=NCCVSR8xAbYLXG0cdYkANfI10p85L1V6g6qlD+90UsqFgBHDDCk25jx5bc+7H+UbujOVReW4e7GcpKV2RdqfcZJCTVl6RI/jnHAt434lGGWl6nuDtPXPsq1CupjYUkkAWtSAd2LL1mC+yPpaTs8cwPy9sxU8YA1t/4HpyJ3zEjE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=c2zJrjyd; 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="c2zJrjyd" Received: by smtp.kernel.org (Postfix) with ESMTPSA id BDAA61F00A3D; Tue, 28 Jul 2026 12:11:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1785240679; bh=ghuphc54DuyJ0SRC2B3/c7k0zTSFneeIGv319symQpo=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=c2zJrjydh6MwYV6IZQ751ZHPkOk8q88rqs/qqI9lNSVV07hSkLrQun5bFfPno9+k2 9B0LbjMPnS9qgYCrpOigSx4tQgcJHzVk35I50ssMRG78n8lw4FihDh5PY668WpFszn 6HNxShRqFR6xwvEGUTt2KIpdhVfITZQ60na1pZ5URDYOIOdJOMAblBrdNITAz6Nf4S skSNcyj6UegkqLZ43wWHw7Yq1I4TQDGy9vptisQOmOrUG5XCEOA/vTZBPwAX5u9cHg FZa0mlmF7rgzluUSigcojLEigDDDvy0l9M4rYlA1HFBJtUtOGaiFZNXgKu6l6mriD2 uOt0NguWDIQ8w== From: Sasha Levin To: stable@vger.kernel.org Cc: Maoyi Xie , Xiao Liang , Kuniyuki Iwashima , Jakub Kicinski , Sasha Levin Subject: [PATCH 5.15.y 2/2] net: ipip: require CAP_NET_ADMIN in the device netns for changelink Date: Tue, 28 Jul 2026 08:11:16 -0400 Message-ID: <20260728121116.3703252-2-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260728121116.3703252-1-sashal@kernel.org> References: <2026072005-sabotage-stylized-6dae@gregkh> <20260728121116.3703252-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Maoyi Xie [ Upstream commit 8211a26324667980a463c069469a818e71207e02 ] ipip_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 ipip_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: 6c742e714d8c ("ipip: add x-netns support") Cc: stable@vger.kernel.org Signed-off-by: Maoyi Xie Reviewed-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20260612085941.3158249-3-maoyixie.tju@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/ipv4/ipip.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/ipv4/ipip.c b/net/ipv4/ipip.c index ae4bd3a3ef8156..d22d8e5f4abc1b 100644 --- a/net/ipv4/ipip.c +++ b/net/ipv4/ipip.c @@ -478,6 +478,9 @@ static int ipip_changelink(struct net_device *dev, struct nlattr *tb[], bool collect_md; __u32 fwmark = t->fwmark; + if (!rtnl_dev_link_net_capable(dev, t->net)) + return -EPERM; + if (ip_tunnel_netlink_encap_parms(data, &ipencap)) { int err = ip_tunnel_encap_setup(t, &ipencap); -- 2.53.0