| From 10414014bc085aac9f787a5890b33b5605fbcfc4 Mon Sep 17 00:00:00 2001 |
| From: Paolo Abeni <pabeni@redhat.com> |
| Date: Mon, 12 Feb 2018 18:49:39 +0100 |
| Subject: netfilter: x_tables: fix missing timer initialization in xt_LED |
| |
| From: Paolo Abeni <pabeni@redhat.com> |
| |
| 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 <pabeni@redhat.com> |
| Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| 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); |
| |