From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id AF3CBC2D0C6 for ; Fri, 27 Dec 2019 17:52:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7FB522173E for ; Fri, 27 Dec 2019 17:52:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1577469141; bh=KVVau5kx2AZE+Txbor4CtEyVXuiFUWTZ6k2C6FlSwmQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=efGSzeWSGuBEMFXcmCScs4N+EAim9gzy2AsQBpHsugE0YK7uxYaH10V2VJBxrvbKS M/X2jmYmuu72gPi5jCWVRQTwLd+wpFi+HMVesOb9XpYmHyQhglO5FgpQrEfeovIUMp Bwmq4OWwOg+uvZbLGjcOTxNPDGtMMBpF2rrGUNFY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728331AbfL0RwU (ORCPT ); Fri, 27 Dec 2019 12:52:20 -0500 Received: from mail.kernel.org ([198.145.29.99]:40592 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728134AbfL0RnN (ORCPT ); Fri, 27 Dec 2019 12:43:13 -0500 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id E6F942176D; Fri, 27 Dec 2019 17:43:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1577468592; bh=KVVau5kx2AZE+Txbor4CtEyVXuiFUWTZ6k2C6FlSwmQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=MOaoWtryahjnXNg9PEiqphHAH16n6f1woL+kcPwuSAmFmvHjHu/gI1idwxUJhy7UZ 2kRIftp7Un0wNbok+JS0jeJeGT2jkz66X38rrxm8eLXE5Pi5qwg7VB9zuYv9J66GC1 ikYtsK55UYs4wVbv9I886ZLHFxYxY212J6+tfANk= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Taehee Yoo , Jakub Kicinski , Sasha Levin , osmocom-net-gprs@lists.osmocom.org, netdev@vger.kernel.org Subject: [PATCH AUTOSEL 5.4 114/187] gtp: fix an use-after-free in ipv4_pdp_find() Date: Fri, 27 Dec 2019 12:39:42 -0500 Message-Id: <20191227174055.4923-114-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20191227174055.4923-1-sashal@kernel.org> References: <20191227174055.4923-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Taehee Yoo [ Upstream commit 94dc550a5062030569d4aa76e10e50c8fc001930 ] ipv4_pdp_find() is called in TX packet path of GTP. ipv4_pdp_find() internally uses gtp->tid_hash to lookup pdp context. In the current code, gtp->tid_hash and gtp->addr_hash are freed by ->dellink(), which is gtp_dellink(). But gtp_dellink() would be called while packets are processing. So, gtp_dellink() should not free gtp->tid_hash and gtp->addr_hash. Instead, dev->priv_destructor() would be used because this callback is called after all packet processing safely. Test commands: ip link add veth1 type veth peer name veth2 ip a a 172.0.0.1/24 dev veth1 ip link set veth1 up ip a a 172.99.0.1/32 dev lo gtp-link add gtp1 & gtp-tunnel add gtp1 v1 200 100 172.99.0.2 172.0.0.2 ip r a 172.99.0.2/32 dev gtp1 ip link set gtp1 mtu 1500 ip netns add ns2 ip link set veth2 netns ns2 ip netns exec ns2 ip a a 172.0.0.2/24 dev veth2 ip netns exec ns2 ip link set veth2 up ip netns exec ns2 ip a a 172.99.0.2/32 dev lo ip netns exec ns2 ip link set lo up ip netns exec ns2 gtp-link add gtp2 & ip netns exec ns2 gtp-tunnel add gtp2 v1 100 200 172.99.0.1 172.0.0.1 ip netns exec ns2 ip r a 172.99.0.1/32 dev gtp2 ip netns exec ns2 ip link set gtp2 mtu 1500 hping3 172.99.0.2 -2 --flood & ip link del gtp1 Splat looks like: [ 72.568081][ T1195] BUG: KASAN: use-after-free in ipv4_pdp_find.isra.12+0x130/0x170 [gtp] [ 72.568916][ T1195] Read of size 8 at addr ffff8880b9a35d28 by task hping3/1195 [ 72.569631][ T1195] [ 72.569861][ T1195] CPU: 2 PID: 1195 Comm: hping3 Not tainted 5.5.0-rc1 #199 [ 72.570547][ T1195] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006 [ 72.571438][ T1195] Call Trace: [ 72.571764][ T1195] dump_stack+0x96/0xdb [ 72.572171][ T1195] ? ipv4_pdp_find.isra.12+0x130/0x170 [gtp] [ 72.572761][ T1195] print_address_description.constprop.5+0x1be/0x360 [ 72.573400][ T1195] ? ipv4_pdp_find.isra.12+0x130/0x170 [gtp] [ 72.573971][ T1195] ? ipv4_pdp_find.isra.12+0x130/0x170 [gtp] [ 72.574544][ T1195] __kasan_report+0x12a/0x16f [ 72.575014][ T1195] ? ipv4_pdp_find.isra.12+0x130/0x170 [gtp] [ 72.575593][ T1195] kasan_report+0xe/0x20 [ 72.576004][ T1195] ipv4_pdp_find.isra.12+0x130/0x170 [gtp] [ 72.576577][ T1195] gtp_build_skb_ip4+0x199/0x1420 [gtp] [ ... ] [ 72.647671][ T1195] BUG: unable to handle page fault for address: ffff8880b9a35d28 [ 72.648512][ T1195] #PF: supervisor read access in kernel mode [ 72.649158][ T1195] #PF: error_code(0x0000) - not-present page [ 72.649849][ T1195] PGD a6c01067 P4D a6c01067 PUD 11fb07067 PMD 11f939067 PTE 800fffff465ca060 [ 72.652958][ T1195] Oops: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN PTI [ 72.653834][ T1195] CPU: 2 PID: 1195 Comm: hping3 Tainted: G B 5.5.0-rc1 #199 [ 72.668062][ T1195] RIP: 0010:ipv4_pdp_find.isra.12+0x86/0x170 [gtp] [ ... ] [ 72.679168][ T1195] Call Trace: [ 72.679603][ T1195] gtp_build_skb_ip4+0x199/0x1420 [gtp] [ 72.681915][ T1195] ? ipv4_pdp_find.isra.12+0x170/0x170 [gtp] [ 72.682513][ T1195] ? lock_acquire+0x164/0x3b0 [ 72.682966][ T1195] ? gtp_dev_xmit+0x35e/0x890 [gtp] [ 72.683481][ T1195] gtp_dev_xmit+0x3c2/0x890 [gtp] [ ... ] Fixes: 459aa660eb1d ("gtp: add initial driver for datapath of GPRS Tunneling Protocol (GTP-U)") Signed-off-by: Taehee Yoo Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- drivers/net/gtp.c | 34 +++++++++++++++++----------------- 1 file changed, 17 insertions(+), 17 deletions(-) diff --git a/drivers/net/gtp.c b/drivers/net/gtp.c index a010e0a11c33..5450b1099c6d 100644 --- a/drivers/net/gtp.c +++ b/drivers/net/gtp.c @@ -640,9 +640,16 @@ static void gtp_link_setup(struct net_device *dev) } static int gtp_hashtable_new(struct gtp_dev *gtp, int hsize); -static void gtp_hashtable_free(struct gtp_dev *gtp); static int gtp_encap_enable(struct gtp_dev *gtp, struct nlattr *data[]); +static void gtp_destructor(struct net_device *dev) +{ + struct gtp_dev *gtp = netdev_priv(dev); + + kfree(gtp->addr_hash); + kfree(gtp->tid_hash); +} + static int gtp_newlink(struct net *src_net, struct net_device *dev, struct nlattr *tb[], struct nlattr *data[], struct netlink_ext_ack *extack) @@ -677,13 +684,15 @@ static int gtp_newlink(struct net *src_net, struct net_device *dev, gn = net_generic(dev_net(dev), gtp_net_id); list_add_rcu(>p->list, &gn->gtp_dev_list); + dev->priv_destructor = gtp_destructor; netdev_dbg(dev, "registered new GTP interface\n"); return 0; out_hashtable: - gtp_hashtable_free(gtp); + kfree(gtp->addr_hash); + kfree(gtp->tid_hash); out_encap: gtp_encap_disable(gtp); return err; @@ -692,8 +701,13 @@ static int gtp_newlink(struct net *src_net, struct net_device *dev, static void gtp_dellink(struct net_device *dev, struct list_head *head) { struct gtp_dev *gtp = netdev_priv(dev); + struct pdp_ctx *pctx; + int i; + + for (i = 0; i < gtp->hash_size; i++) + hlist_for_each_entry_rcu(pctx, >p->tid_hash[i], hlist_tid) + pdp_context_delete(pctx); - gtp_hashtable_free(gtp); list_del_rcu(>p->list); unregister_netdevice_queue(dev, head); } @@ -771,20 +785,6 @@ static int gtp_hashtable_new(struct gtp_dev *gtp, int hsize) return -ENOMEM; } -static void gtp_hashtable_free(struct gtp_dev *gtp) -{ - struct pdp_ctx *pctx; - int i; - - for (i = 0; i < gtp->hash_size; i++) - hlist_for_each_entry_rcu(pctx, >p->tid_hash[i], hlist_tid) - pdp_context_delete(pctx); - - synchronize_rcu(); - kfree(gtp->addr_hash); - kfree(gtp->tid_hash); -} - static struct sock *gtp_encap_enable_socket(int fd, int type, struct gtp_dev *gtp) { -- 2.20.1