Free memory is -13316kB above reserved
lowmemorykiller: Killing 'syz-executor4' (22220) (tgid 22217), adj 1000,
   to free 51380kB on behalf of 'rs:main Q:Reg' (1887) because
   cache 748kB is below limit 6144kB for oom_score_adj 0
   Free memory is -13316kB above reserved
INFO: task syz-executor1:22178 blocked for more than 140 seconds.
      Not tainted 4.9.141+ #23
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor1   D30184 22178   2064 0x20020004
 ffff88009ea82f80 ffff8800730e9080 ffff8801ae6ec780 ffff88006e5217c0
 ffff8801db721018 ffff8800af247a88 ffffffff828075c2 ffff8800af247b08
 ffff88009ea82f80 ffffffff810efada 00fffc0000000000 ffff8801db7218f0
Call Trace:
 [<ffffffff82808aef>] schedule+0x7f/0x1b0 kernel/sched/core.c:3553
 [<ffffffff822acffc>] __lock_sock+0x13c/0x250 net/core/sock.c:2035
 [<ffffffff822ad206>] lock_sock_nested+0xf6/0x120 net/core/sock.c:2505
 [<ffffffff827d1f3f>] lock_sock include/net/sock.h:1404 [inline]
 [<ffffffff827d1f3f>] packet_setsockopt+0x50f/0x2630 net/packet/af_packet.c:3668
 [<ffffffff827d4141>] compat_packet_setsockopt+0xe1/0x140 net/packet/af_packet.c:4016
 [<ffffffff8238f7d9>] C_SYSC_setsockopt net/compat.c:399 [inline]
 [<ffffffff8238f7d9>] compat_SyS_setsockopt+0x169/0x550 net/compat.c:382
lowmemorykiller: Killing 'syz-executor4' (22220) (tgid 22217), adj 1000,
   to free 51380kB on behalf of 'cron' (1941) because
   cache 664kB is below limit 6144kB for oom_score_adj 0
   Free memory is -13184kB above reserved
 [<ffffffff81006311>] do_syscall_32_irqs_on arch/x86/entry/common.c:328 [inline]
 [<ffffffff81006311>] do_fast_syscall_32+0x2f1/0xa10 arch/x86/entry/common.c:390
 [<ffffffff82818de0>] entry_SYSENTER_compat+0x90/0xa2 arch/x86/entry/entry_64_compat.S:137

Showing all locks held in the system:
2 locks held by khungtaskd/24:
 #0:  (rcu_read_lock){......}, at: [<ffffffff8131c2c0>] rcu_read_unlock include/linux/rcupdate.h:927 [inline]
 #0:  (rcu_read_lock){......}, at: [<ffffffff8131c2c0>] rcu_lock_break kernel/hung_task.c:143 [inline]
 #0:  (rcu_read_lock){......}, at: [<ffffffff8131c2c0>] check_hung_uninterruptible_tasks kernel/hung_task.c:177 [inline]
 #0:  (rcu_read_lock){......}, at: [<ffffffff8131c2c0>] watchdog+0x310/0xa20 kernel/hung_task.c:239
 #1:  (tasklist_lock){.+.+..}, at: [<ffffffff813fe63f>] debug_show_all_locks+0x79/0x218 kernel/locking/lockdep.c:4336
2 locks held by getty/2017:
 #0:  (&tty->ldisc_sem){++++++}, at: [<ffffffff82815952>] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367
 #1:  (&ldata->atomic_read_lock){+.+.+.}, at: [<ffffffff81d37362>] n_tty_read+0x202/0x16e0 drivers/tty/n_tty.c:2142
1 lock held by syz-executor0/10489:
 #0:  (&sig->cred_guard_mutex){+.+.+.}, at: [<ffffffff81520d73>] prepare_bprm_creds+0x53/0x110 fs/exec.c:1369
3 locks held by kworker/0:4/18077:
 #0:  ("%s"("ipv6_addrconf")){.+.+..}, at: [<ffffffff81130f0c>] process_one_work+0x73c/0x15f0 kernel/workqueue.c:2085
 #1:  ((addr_chk_work).work){+.+...}, at: [<ffffffff81130f44>] process_one_work+0x774/0x15f0 kernel/workqueue.c:2089
 #2:  (rtnl_mutex){+.+.+.}, at: [<ffffffff823412d7>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
1 lock held by syz-executor4/22220:
 #0:  (net_mutex){+.+.+.}, at: [<ffffffff822e70e5>] copy_net_ns+0x155/0x330 net/core/net_namespace.c:406
1 lock held by syz-executor3/22240:
 #0:  (net_mutex){+.+.+.}, at: [<ffffffff822e70e5>] copy_net_ns+0x155/0x330 net/core/net_namespace.c:406
1 lock held by syz-executor5/22239:
 #0:  (net_mutex){+.+.+.}, at: [<ffffffff822e70e5>] copy_net_ns+0x155/0x330 net/core/net_namespace.c:406

=============================================

NMI backtrace for cpu 0
CPU: 0 PID: 24 Comm: khungtaskd Not tainted 4.9.141+ #23
 ffff8801d9907d08 ffffffff81b42e79 0000000000000000 0000000000000000
 0000000000000000 0000000000000001 ffffffff810983b0 ffff8801d9907d40
 ffffffff81b4df89 0000000000000000 0000000000000000 0000000000000003
Call Trace:
 [<ffffffff81b42e79>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81b42e79>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff81b4df89>] nmi_cpu_backtrace.cold.0+0x48/0x87 lib/nmi_backtrace.c:99
 [<ffffffff81b4df1c>] nmi_trigger_cpumask_backtrace+0x12c/0x151 lib/nmi_backtrace.c:60
 [<ffffffff810984b4>] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37
lowmemorykiller: Killing 'syz-executor4' (22220) (tgid 22217), adj 1000,
   to free 51380kB on behalf of 'kswapd0' (33) because
   cache 664kB is below limit 6144kB for oom_score_adj 0
   Free memory is -13184kB above reserved
 [<ffffffff8131c65d>] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline]
 [<ffffffff8131c65d>] check_hung_task kernel/hung_task.c:125 [inline]
 [<ffffffff8131c65d>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<ffffffff8131c65d>] watchdog+0x6ad/0xa20 kernel/hung_task.c:239
 [<ffffffff81142c3d>] kthread+0x26d/0x300 kernel/kthread.c:211
 [<ffffffff82817a5c>] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:373
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 33 Comm: kswapd0 Not tainted 4.9.141+ #23
task: ffff8801d8410000 task.stack: ffff8801d8418000
RIP: 0010:[<ffffffff81215556>] 
c [<ffffffff81215556>] debug_spin_unlock kernel/locking/spinlock_debug.c:103 [inline]
RIP: 0010:[<ffffffff81215556>] 
c [<ffffffff81215556>] do_raw_spin_unlock+0x116/0x210 kernel/locking/spinlock_debug.c:134
RSP: 0000:ffff8801d841f8b0  EFLAGS: 00000a02
RAX: dffffc0000000000 RBX: ffff88009a9ee6c0 RCX: 0000000000000002
RDX: 1ffff1001353dcd9 RSI: 0000000000000002 RDI: ffff88009a9ee6c4
RBP: ffff8801d841f8c8 R08: ffff8801d8410920 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000001 R12: ffff88009a9ee6c8
R13: ffff88009a9ee6d0 R14: ffff88009a9edf00 R15: 0000000000000600
FS:  0000000000000000(0000) GS:ffff8801db700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000418601 CR3: 00000001d62a8000 CR4: 00000000001606b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 ffff88009a9ee6c0
c dffffc0000000000
c 0000000000002204
c ffff8801d841f8e0
c
 ffffffff82816ef2
c ffff88009a9edf00
c ffff8801d841f990
c ffffffff821f0166
c
 ffffffff821efede
c ffff880100000021
c 0000000000000298
c 0000000000000246
c
Call Trace:
 [<ffffffff82816ef2>] __raw_spin_unlock include/linux/spinlock_api_smp.h:153 [inline]
 [<ffffffff82816ef2>] _raw_spin_unlock+0x22/0x50 kernel/locking/spinlock.c:183
 [<ffffffff821f0166>] spin_unlock include/linux/spinlock.h:347 [inline]
 [<ffffffff821f0166>] task_unlock include/linux/sched.h:3262 [inline]
 [<ffffffff821f0166>] lowmem_scan+0x4d6/0xaf0 drivers/staging/android/lowmemorykiller.c:150
 [<ffffffff81449cc6>] do_shrink_slab mm/vmscan.c:398 [inline]
 [<ffffffff81449cc6>] shrink_slab.part.8+0x3c6/0xa00 mm/vmscan.c:501
 [<ffffffff814557fd>] shrink_slab mm/vmscan.c:465 [inline]
 [<ffffffff814557fd>] shrink_node+0x1ed/0x740 mm/vmscan.c:2602
 [<ffffffff814570b9>] kswapd_shrink_node mm/vmscan.c:3202 [inline]
 [<ffffffff814570b9>] balance_pgdat mm/vmscan.c:3319 [inline]
 [<ffffffff814570b9>] kswapd+0x7e9/0x13b0 mm/vmscan.c:3512
 [<ffffffff81142c3d>] kthread+0x26d/0x300 kernel/kthread.c:211
 [<ffffffff82817a5c>] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:373
Code: 
cdf 
c4c 
c89 
cea 
c48 
cc1 
cea 
c03 
c80 
c3c 
c02 
c00 
c0f 
c85 
cf6 
c00 
c00 
c00 
c4c 
c89 
ce2 
c48 
cc7 
c43 
c10 
cff 
cff 
cff 
cff 
c48 
cb8 
c00 
c00 
c00 
c00 
c00 
cfc 
cff 
cdf 
c48 
cc1 
cea 
c03 
c<0f> 
cb6 
c04 
c02 
c84 
cc0 
c74 
c08 
c3c 
c03 
c0f 
c8e 
cc0 
c00 
c00 
c00 
cc7 
c43 
c08 
cff 
cff 
c
lowmemorykiller: Killing 'syz-executor4' (22220) (tgid 22217), adj 1000,
   to free 51380kB on behalf of 'syz-executor0' (2061) because
   cache 600kB is below limit 6144kB for oom_score_adj 0
   Free memory is -13184kB above reserved
lowmemorykiller: Killing 'syz-executor4' (22220) (tgid 22217), adj 1000,
   to free 51380kB on behalf of 'init' (1) because
   cache 600kB is below limit 6144kB for oom_score_adj 0
   Free memory is -13184kB above reserved