[PATCH 4.15 111/146] netfilter: x_tables: fix missing timer initialization in xt_LED

2018-03-13 Thread Greg Kroah-Hartman 
4.15-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:  [#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: 0018:8801d24fe9f8 EFLAGS: 00010293
RAX: 8801d25246c0 RBX: 8801aec6cb50 RCX: 816052c6
RDX:  RSI: fffbd14b RDI: 8801aec6cb68
RBP: 8801d24fec98 R08:  R09: 11003a49fd6c
R10: 8801d24feb28 R11: 0005 R12: dc00
R13: 8801d24fec70 R14: fffbd14b R15: 8801af608f90
FS:  () GS:8801db50() knlGS:
CS:  0010 DS:  ES:  CR0: 80050033
CR2: 206d6fd0 CR3: 06a22001 CR4: 001606e0
DR0:  DR1:  DR2: 
DR3:  DR6: fffe0ff0 DR7: 0400
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: 8801d24fe9f8
RIP: mod_timer+0x7d6/0x13c0 kernel/time/timer.c:1102 RSP: 8801d24fe9f8
---[ 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+10c98dc5725c6c8fc...@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 |   10 +-
 1 file changed, 5 insertions(+), 5 deletions(-)

--- a/net/netfilter/xt_LED.c
+++ b/net/netfilter/xt_LED.c
@@ -142,9 +142,10 @@ static int led_tg_check(const struct xt_
goto exit_alloc;
}
 
-   /* See if we need to set up a timer */
-   if (ledinfo->delay > 0)
-   timer_setup(>timer, led_timeout_callback, 0);
+   /* Since the letinternal timer can be shared between multiple targets,
+* always set it up, even if the current target does not need it
+*/
+   timer_setup(>timer, led_timeout_callback, 0);
 
list_add_tail(>list, _led_triggers);
 
@@ -181,8 +182,7 @@ static void led_tg_destroy(const struct
 
list_del(>list);
 
-   if (ledinfo->delay > 0)
-   del_timer_sync(>timer);
+   del_timer_sync(>timer);
 
led_trigger_unregister(>netfilter_led_trigger);

[PATCH 4.15 111/146] netfilter: x_tables: fix missing timer initialization in xt_LED

2018-03-13 Thread Greg Kroah-Hartman 
4.15-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:  [#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: 0018:8801d24fe9f8 EFLAGS: 00010293
RAX: 8801d25246c0 RBX: 8801aec6cb50 RCX: 816052c6
RDX:  RSI: fffbd14b RDI: 8801aec6cb68
RBP: 8801d24fec98 R08:  R09: 11003a49fd6c
R10: 8801d24feb28 R11: 0005 R12: dc00
R13: 8801d24fec70 R14: fffbd14b R15: 8801af608f90
FS:  () GS:8801db50() knlGS:
CS:  0010 DS:  ES:  CR0: 80050033
CR2: 206d6fd0 CR3: 06a22001 CR4: 001606e0
DR0:  DR1:  DR2: 
DR3:  DR6: fffe0ff0 DR7: 0400
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: 8801d24fe9f8
RIP: mod_timer+0x7d6/0x13c0 kernel/time/timer.c:1102 RSP: 8801d24fe9f8
---[ 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+10c98dc5725c6c8fc...@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 |   10 +-
 1 file changed, 5 insertions(+), 5 deletions(-)

--- a/net/netfilter/xt_LED.c
+++ b/net/netfilter/xt_LED.c
@@ -142,9 +142,10 @@ static int led_tg_check(const struct xt_
goto exit_alloc;
}
 
-   /* See if we need to set up a timer */
-   if (ledinfo->delay > 0)
-   timer_setup(>timer, led_timeout_callback, 0);
+   /* Since the letinternal timer can be shared between multiple targets,
+* always set it up, even if the current target does not need it
+*/
+   timer_setup(>timer, led_timeout_callback, 0);
 
list_add_tail(>list, _led_triggers);
 
@@ -181,8 +182,7 @@ static void led_tg_destroy(const struct
 
list_del(>list);
 
-   if (ledinfo->delay > 0)
-   del_timer_sync(>timer);
+   del_timer_sync(>timer);
 
led_trigger_unregister(>netfilter_led_trigger);