From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp.codeaurora.org by pdx-caf-mail.web.codeaurora.org (Dovecot) with LMTP id ktfqMYM/GVvjWgAAmS7hNA ; Thu, 07 Jun 2018 14:22:03 +0000 Received: by smtp.codeaurora.org (Postfix, from userid 1000) id BC1BE608D4; Thu, 7 Jun 2018 14:22:03 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on pdx-caf-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI autolearn=ham autolearn_force=no version=3.4.0 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by smtp.codeaurora.org (Postfix) with ESMTP id 13EBA608CE; Thu, 7 Jun 2018 14:22:03 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 13EBA608CE Authentication-Results: pdx-caf-mail.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=decadent.org.uk Authentication-Results: pdx-caf-mail.web.codeaurora.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933558AbeFGOWB (ORCPT + 25 others); Thu, 7 Jun 2018 10:22:01 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:39434 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933072AbeFGOJK (ORCPT ); Thu, 7 Jun 2018 10:09:10 -0400 Received: from [148.252.241.226] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.84_2) (envelope-from ) id 1fQvbA-0005Zx-Lh; Thu, 07 Jun 2018 15:09:08 +0100 Received: from ben by deadeye with local (Exim 4.91) (envelope-from ) id 1fQvb7-00033X-HU; Thu, 07 Jun 2018 15:09:05 +0100 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Pablo Neira Ayuso" , syzbot+10c98dc5725c6c8fc7fb@syzkaller.appspotmail.com, "Paolo Abeni" Date: Thu, 07 Jun 2018 15:05:21 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 236/410] netfilter: x_tables: fix missing timer initialization in xt_LED In-Reply-To: X-SA-Exim-Connect-IP: 148.252.241.226 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.57-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Paolo Abeni commit 10414014bc085aac9f787a5890b33b5605fbcfc4 upstream. syzbot reported that xt_LED may try to use the ledinternal->timer without previously initializing it: ------------[ cut here ]------------ kernel BUG at kernel/time/timer.c:958! invalid opcode: 0000 [#1] SMP KASAN Dumping ftrace buffer: (ftrace buffer empty) Modules linked in: CPU: 1 PID: 1826 Comm: kworker/1:2 Not tainted 4.15.0+ #306 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: ipv6_addrconf addrconf_dad_work RIP: 0010:__mod_timer kernel/time/timer.c:958 [inline] RIP: 0010:mod_timer+0x7d6/0x13c0 kernel/time/timer.c:1102 RSP: 0018:ffff8801d24fe9f8 EFLAGS: 00010293 RAX: ffff8801d25246c0 RBX: ffff8801aec6cb50 RCX: ffffffff816052c6 RDX: 0000000000000000 RSI: 00000000fffbd14b RDI: ffff8801aec6cb68 RBP: ffff8801d24fec98 R08: 0000000000000000 R09: 1ffff1003a49fd6c R10: ffff8801d24feb28 R11: 0000000000000005 R12: dffffc0000000000 R13: ffff8801d24fec70 R14: 00000000fffbd14b R15: ffff8801af608f90 FS: 0000000000000000(0000) GS:ffff8801db500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000206d6fd0 CR3: 0000000006a22001 CR4: 00000000001606e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: led_tg+0x1db/0x2e0 net/netfilter/xt_LED.c:75 ip6t_do_table+0xc2a/0x1a30 net/ipv6/netfilter/ip6_tables.c:365 ip6table_raw_hook+0x65/0x80 net/ipv6/netfilter/ip6table_raw.c:42 nf_hook_entry_hookfn include/linux/netfilter.h:120 [inline] nf_hook_slow+0xba/0x1a0 net/netfilter/core.c:483 nf_hook.constprop.27+0x3f6/0x830 include/linux/netfilter.h:243 NF_HOOK include/linux/netfilter.h:286 [inline] ndisc_send_skb+0xa51/0x1370 net/ipv6/ndisc.c:491 ndisc_send_ns+0x38a/0x870 net/ipv6/ndisc.c:633 addrconf_dad_work+0xb9e/0x1320 net/ipv6/addrconf.c:4008 process_one_work+0xbbf/0x1af0 kernel/workqueue.c:2113 worker_thread+0x223/0x1990 kernel/workqueue.c:2247 kthread+0x33c/0x400 kernel/kthread.c:238 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:429 Code: 85 2a 0b 00 00 4d 8b 3c 24 4d 85 ff 75 9f 4c 8b bd 60 fd ff ff e8 bb 57 10 00 65 ff 0d 94 9a a1 7e e9 d9 fc ff ff e8 aa 57 10 00 <0f> 0b e8 a3 57 10 00 e9 14 fb ff ff e8 99 57 10 00 4c 89 bd 70 RIP: __mod_timer kernel/time/timer.c:958 [inline] RSP: ffff8801d24fe9f8 RIP: mod_timer+0x7d6/0x13c0 kernel/time/timer.c:1102 RSP: ffff8801d24fe9f8 ---[ end trace f661ab06f5dd8b3d ]--- The ledinternal struct can be shared between several different xt_LED targets, but the related timer is currently initialized only if the first target requires it. Fix it by unconditionally initializing the timer struct. v1 -> v2: call del_timer_sync() unconditionally, too. Fixes: 268cb38e1802 ("netfilter: x_tables: add LED trigger target") Reported-by: syzbot+10c98dc5725c6c8fc7fb@syzkaller.appspotmail.com Signed-off-by: Paolo Abeni Signed-off-by: Pablo Neira Ayuso [bwh: Backported to 3.16: Keep using setup_timer()] Signed-off-by: Ben Hutchings --- --- a/net/netfilter/xt_LED.c +++ b/net/netfilter/xt_LED.c @@ -139,10 +139,11 @@ static int led_tg_check(const struct xt_ goto exit_alloc; } - /* See if we need to set up a timer */ - if (ledinfo->delay > 0) - setup_timer(&ledinternal->timer, led_timeout_callback, - (unsigned long)ledinternal); + /* Since the letinternal timer can be shared between multiple targets, + * always set it up, even if the current target does not need it + */ + setup_timer(&ledinternal->timer, led_timeout_callback, + (unsigned long)ledinternal); list_add_tail(&ledinternal->list, &xt_led_triggers); @@ -179,8 +180,7 @@ static void led_tg_destroy(const struct list_del(&ledinternal->list); - if (ledinfo->delay > 0) - del_timer_sync(&ledinternal->timer); + del_timer_sync(&ledinternal->timer); led_trigger_unregister(&ledinternal->netfilter_led_trigger);