From patchwork Tue Oct 20 22:02:40 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Davide Caratti X-Patchwork-Id: 288246 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=-9.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS 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 1BD37C4363A for ; Tue, 20 Oct 2020 22:03:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 980702225C for ; Tue, 20 Oct 2020 22:03:31 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="HVXyIxEq" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2393567AbgJTWDa (ORCPT ); Tue, 20 Oct 2020 18:03:30 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:39726 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2392433AbgJTWDa (ORCPT ); Tue, 20 Oct 2020 18:03:30 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1603231408; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=Hit0A3zU+BLs5Zn3mD9VZrgVkzbagQuBiVegcEx1zq8=; b=HVXyIxEqBdgA3p9IMo7gHHBWCGLMwzMDI0uvC1eZbVFUlpE3//iAKmlEZG4Xl4KQF9J+hm 5141dlK0qJkYsfTjlgoyT9fNUz1dJRTiDp692MRoGrClJy4jPIsZRgecOd+pXqN8aEMh+i GCLMS7hy/QtqXMEywPD3j9RDmhECWwA= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-471-QkHrJi94Nv27XsNnTbNnog-1; Tue, 20 Oct 2020 18:03:24 -0400 X-MC-Unique: QkHrJi94Nv27XsNnTbNnog-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id AD9861084D61; Tue, 20 Oct 2020 22:03:22 +0000 (UTC) Received: from new-host-6.redhat.com (unknown [10.40.193.216]) by smtp.corp.redhat.com (Postfix) with ESMTP id 066306266E; Tue, 20 Oct 2020 22:03:19 +0000 (UTC) From: Davide Caratti To: Jakub Kicinski , "David S. Miller" , Jiri Pirko , Cong Wang , Jamal Hadi Salim Cc: Simon Horman , Shuang Li , netdev@vger.kernel.org Subject: [PATCH net] net/sched: act_tunnel_key: fix OOB write in case of IPv6 ERSPAN tunnels Date: Wed, 21 Oct 2020 00:02:40 +0200 Message-Id: <36ebe969f6d13ff59912d6464a4356fe6f103766.1603231100.git.dcaratti@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org the following command # tc action add action tunnel_key \ > set src_ip 2001:db8::1 dst_ip 2001:db8::2 id 10 erspan_opts 1:6789:0:0 generates the following splat: BUG: KASAN: slab-out-of-bounds in tunnel_key_copy_opts+0xcc9/0x1010 [act_tunnel_key] Write of size 4 at addr ffff88813f5f1cc8 by task tc/873 CPU: 2 PID: 873 Comm: tc Not tainted 5.9.0+ #282 Hardware name: Red Hat KVM, BIOS 1.11.1-4.module+el8.1.0+4066+0f1aadab 04/01/2014 Call Trace: dump_stack+0x99/0xcb print_address_description.constprop.7+0x1e/0x230 kasan_report.cold.13+0x37/0x7c tunnel_key_copy_opts+0xcc9/0x1010 [act_tunnel_key] tunnel_key_init+0x160c/0x1f40 [act_tunnel_key] tcf_action_init_1+0x5b5/0x850 tcf_action_init+0x15d/0x370 tcf_action_add+0xd9/0x2f0 tc_ctl_action+0x29b/0x3a0 rtnetlink_rcv_msg+0x341/0x8d0 netlink_rcv_skb+0x120/0x380 netlink_unicast+0x439/0x630 netlink_sendmsg+0x719/0xbf0 sock_sendmsg+0xe2/0x110 ____sys_sendmsg+0x5ba/0x890 ___sys_sendmsg+0xe9/0x160 __sys_sendmsg+0xd3/0x170 do_syscall_64+0x33/0x40 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7f872a96b338 Code: 89 02 48 c7 c0 ff ff ff ff eb b5 0f 1f 80 00 00 00 00 f3 0f 1e fa 48 8d 05 25 43 2c 00 8b 00 85 c0 75 17 b8 2e 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 58 c3 0f 1f 80 00 00 00 00 41 54 41 89 d4 55 RSP: 002b:00007ffffe367518 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 000000005f8f5aed RCX: 00007f872a96b338 RDX: 0000000000000000 RSI: 00007ffffe367580 RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000001 R09: 000000000000001c R10: 000000000000000b R11: 0000000000000246 R12: 0000000000000001 R13: 0000000000686760 R14: 0000000000000601 R15: 0000000000000000 Allocated by task 873: kasan_save_stack+0x19/0x40 __kasan_kmalloc.constprop.7+0xc1/0xd0 __kmalloc+0x151/0x310 metadata_dst_alloc+0x20/0x40 tunnel_key_init+0xfff/0x1f40 [act_tunnel_key] tcf_action_init_1+0x5b5/0x850 tcf_action_init+0x15d/0x370 tcf_action_add+0xd9/0x2f0 tc_ctl_action+0x29b/0x3a0 rtnetlink_rcv_msg+0x341/0x8d0 netlink_rcv_skb+0x120/0x380 netlink_unicast+0x439/0x630 netlink_sendmsg+0x719/0xbf0 sock_sendmsg+0xe2/0x110 ____sys_sendmsg+0x5ba/0x890 ___sys_sendmsg+0xe9/0x160 __sys_sendmsg+0xd3/0x170 do_syscall_64+0x33/0x40 entry_SYSCALL_64_after_hwframe+0x44/0xa9 The buggy address belongs to the object at ffff88813f5f1c00 which belongs to the cache kmalloc-256 of size 256 The buggy address is located 200 bytes inside of 256-byte region [ffff88813f5f1c00, ffff88813f5f1d00) The buggy address belongs to the page: page:0000000011b48a19 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x13f5f0 head:0000000011b48a19 order:1 compound_mapcount:0 flags: 0x17ffffc0010200(slab|head) raw: 0017ffffc0010200 0000000000000000 0000000d00000001 ffff888107c43400 raw: 0000000000000000 0000000080100010 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88813f5f1b80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88813f5f1c00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff88813f5f1c80: 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc ^ ffff88813f5f1d00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88813f5f1d80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc using IPv6 tunnels, act_tunnel_key allocates a fixed amount of memory for the tunnel metadata, but then it expects additional bytes to store tunnel specific metadata with tunnel_key_copy_opts(). Fix the arguments of __ipv6_tun_set_dst(), so that 'md_size' contains the size previously computed by tunnel_key_get_opts_len(), like it's done for IPv4 tunnels. Fixes: 0ed5269f9e41 ("net/sched: add tunnel option support to act_tunnel_key") Reported-by: Shuang Li Signed-off-by: Davide Caratti Acked-by: Cong Wang --- net/sched/act_tunnel_key.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/sched/act_tunnel_key.c b/net/sched/act_tunnel_key.c index a229751ee8c4..85c0d0d5b9da 100644 --- a/net/sched/act_tunnel_key.c +++ b/net/sched/act_tunnel_key.c @@ -459,7 +459,7 @@ static int tunnel_key_init(struct net *net, struct nlattr *nla, metadata = __ipv6_tun_set_dst(&saddr, &daddr, tos, ttl, dst_port, 0, flags, - key_id, 0); + key_id, opts_len); } else { NL_SET_ERR_MSG(extack, "Missing either ipv4 or ipv6 src and dst"); ret = -EINVAL;