From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AG47ELsbxBYce7v5znExbi2jZgZ+iCvR68bn4Sq/EbCOAUkK/K8ChcRrOZqzlSx7brxxejHnhZj6 ARC-Seal: i=1; a=rsa-sha256; t=1521214325; cv=none; d=google.com; s=arc-20160816; b=JsdKSf1WTGKZ9scBgmeeEW5MNIu9KdZy1lDif62T6N6pGdEWDDdpKHXpmWCvcL3OQZ msKqTjhMPdjqnariC5ksx60cwidWDBDkGeOvaqZaNHRIDZNbXynHJj2ZoXou+vJsE4dO KU6pvP/uoKAi5cD9SN7DNtPX69LZSs4rMQKNhyqYnd7WcURxVgM1jWXT7SNGppTpWer3 +ttIVCyT9yLs3aNe0xjrQJ8/6RfyQT8Cwce/nHzE0EyYdwr8rProtNs59hOSxiOdj8hR UmsYD7ZY3uLSr2c/aBBoZBH0hpcoSes05E8AhZZGXwMfNR2wosKns73SNHBHoQwJr7Pb Z9EA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=mime-version:user-agent:references:in-reply-to:message-id:date :subject:cc:to:from:arc-authentication-results; bh=JJeOTaWflrbAvU6Pz7XvGUCy6fDr/ll8zFE3rbM/vVc=; b=h2VpS5pQgyuyByt6ZPT5FE68C3bxJi+LnLdF2RvRgQHp/mqOnrXeo61il4soEbMCe0 rsvC2IBZpOG6vFp7RrWfvOY30usz5BIYoc/yXht3GUKB1f2u3dKk9Xlpqk7mvCjU/x3Z 6rXlxCVTuUTlyq4L+DYZH18zPIZjIPK4iY/kPvsWZmaf436m4/JQYWDQAcwybHMBUdvV I4BhHqpIj2nduX6UGQoJjeA5lEXi7FKAc+JuGgS0AULPGUjnL1xx6NYXAv/QC7u4N8pv TdsblFOTsFJDEb+hub3vpqROT8cR1m47WgFJ24c2sKwFn3C6BT4STP6C3S35t1Ee7zGr qSCA== ARC-Authentication-Results: i=1; mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 90.92.61.202 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org Authentication-Results: mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 90.92.61.202 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, syzbot+10c98dc5725c6c8fc7fb@syzkaller.appspotmail.com, Paolo Abeni , Pablo Neira Ayuso Subject: [PATCH 4.9 55/86] netfilter: x_tables: fix missing timer initialization in xt_LED Date: Fri, 16 Mar 2018 16:23:18 +0100 Message-Id: <20180316152321.109695553@linuxfoundation.org> X-Mailer: git-send-email 2.16.2 In-Reply-To: <20180316152317.167709497@linuxfoundation.org> References: <20180316152317.167709497@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-LABELS: =?utf-8?b?IlxcU2VudCI=?= X-GMAIL-THRID: =?utf-8?q?1595108302199062197?= X-GMAIL-MSGID: =?utf-8?q?1595108832409245496?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.9-stable 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 Signed-off-by: Greg Kroah-Hartman --- net/netfilter/xt_LED.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) --- a/net/netfilter/xt_LED.c +++ b/net/netfilter/xt_LED.c @@ -141,10 +141,11 @@ 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); @@ -181,8 +182,7 @@ 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);