Free memory is -13444kB above reserved
lowmemorykiller: Killing 'syz-executor.3' (31883) (tgid 31881), adj 1000,
   to free 51404kB on behalf of 'syz-fuzzer' (2044) because
   cache 424kB is below limit 6144kB for oom_score_adj 0
   Free memory is -13444kB above reserved
INFO: task syz-executor.5:2088 blocked for more than 140 seconds.
      Not tainted 4.9.141+ #1
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.5  D24648  2088   2082 0x00000000
 ffff8801d114df00 0000000000000000 ffff8801cf741b80 ffff8801d9942f80
 ffff8801db621018 ffff8801b30cf7d8 ffffffff828075c2 0000000000000000
 ffff8801d114e7b0 ffffed003a229cf5 00ff8801d114df00 ffff8801db6218f0
Call Trace:
 [<ffffffff82808aef>] schedule+0x7f/0x1b0 kernel/sched/core.c:3553
 [<ffffffff828094a3>] schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3586
 [<ffffffff8280b51d>] __mutex_lock_common kernel/locking/mutex.c:582 [inline]
 [<ffffffff8280b51d>] mutex_lock_nested+0x38d/0x900 kernel/locking/mutex.c:621
 [<ffffffff8244fa1c>] xt_find_table_lock+0x3c/0x3d0 net/netfilter/x_tables.c:1027
 [<ffffffff8261a90d>] get_info+0x13d/0x510 net/ipv6/netfilter/ip6_tables.c:1012
 [<ffffffff8261c36b>] do_arpt_get_ctl+0x38b/0x860 net/ipv4/netfilter/arp_tables.c:1492
 [<ffffffff823e2840>] nf_sockopt net/netfilter/nf_sockopt.c:103 [inline]
 [<ffffffff823e2840>] nf_getsockopt+0x70/0xd0 net/netfilter/nf_sockopt.c:121
 [<ffffffff824bd877>] ip_getsockopt+0x127/0x170 net/ipv4/ip_sockglue.c:1557
 [<ffffffff824e0228>] tcp_getsockopt+0x88/0xe0 net/ipv4/tcp.c:3106
 [<ffffffff822a706a>] sock_common_getsockopt+0x9a/0xe0 net/core/sock.c:2665
 [<ffffffff822a4fc0>] SYSC_getsockopt net/socket.c:1816 [inline]
 [<ffffffff822a4fc0>] SyS_getsockopt+0x150/0x240 net/socket.c:1798
 [<ffffffff810056ef>] do_syscall_64+0x19f/0x550 arch/x86/entry/common.c:285
 [<ffffffff82817893>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb

Showing all locks held in the system:
2 locks held by khungtaskd/24:
 #0:  (rcu_read_lock){......}, at: [<ffffffff8131c0cc>] check_hung_uninterruptible_tasks kernel/hung_task.c:168 [inline]
 #0:  (rcu_read_lock){......}, at: [<ffffffff8131c0cc>] watchdog+0x11c/0xa20 kernel/hung_task.c:239
 #1:  (tasklist_lock){.+.+..}, at: [<ffffffff813fe63f>] debug_show_all_locks+0x79/0x218 kernel/locking/lockdep.c:4336
1 lock held by rsyslogd/1891:
 #0:  (&f->f_pos_lock){+.+.+.}, at: [<ffffffff8156cc7c>] __fdget_pos+0xac/0xd0 fs/file.c:781
2 locks held by getty/2018:
 #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-executor.5/2088:
 #0:  (&xt[i].mutex){+.+.+.}, at: [<ffffffff8244fa1c>] xt_find_table_lock+0x3c/0x3d0 net/netfilter/x_tables.c:1027
3 locks held by kworker/1:5/6287:
 #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
3 locks held by kworker/u4:31/15694:
 #0:  ("%s""netns"){.+.+.+}, at: [<ffffffff81130f0c>] process_one_work+0x73c/0x15f0 kernel/workqueue.c:2085
 #1:  (net_cleanup_work){+.+.+.}, at: [<ffffffff81130f44>] process_one_work+0x774/0x15f0 kernel/workqueue.c:2089
 #2:  (net_mutex){+.+.+.}, at: [<ffffffff822e681f>] cleanup_net+0x13f/0x8b0 net/core/net_namespace.c:439
1 lock held by syz-executor.0/21354:
 #0:  (&xt[i].mutex){+.+.+.}, at: [<ffffffff8244fa1c>] xt_find_table_lock+0x3c/0x3d0 net/netfilter/x_tables.c:1027
2 locks held by syz-executor.2/23093:
 #0:  (&tty->ldisc_sem){++++++}, at: [<ffffffff82815952>] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367
 #1:  (&tty->atomic_write_lock){+.+.+.}, at: [<ffffffff81d1f7e1>] tty_write_lock+0x21/0x60 drivers/tty/tty_io.c:1107
1 lock held by syz-executor.3/31883:
 #0:  (net_mutex){+.+.+.}, at: [<ffffffff822e70e5>] copy_net_ns+0x155/0x330 net/core/net_namespace.c:406

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

NMI backtrace for cpu 1
CPU: 1 PID: 24 Comm: khungtaskd Not tainted 4.9.141+ #1
 ffff8801d9907d08 ffffffff81b42e79 0000000000000000 0000000000000001
 0000000000000001 0000000000000001 ffffffff810983b0 ffff8801d9907d40
 ffffffff81b4df89 0000000000000001 0000000000000000 0000000000000002
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
 [<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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 31916 Comm: syz-executor.1 Not tainted 4.9.141+ #1
task: ffff8801d9fe8000 task.stack: ffff88010b150000
RIP: 0010:[<ffffffff8120c91d>] 
c [<ffffffff8120c91d>] lock_acquire+0x17d/0x3e0 kernel/locking/lockdep.c:3760
RSP: 0018:ffff88010b1572f0  EFLAGS: 00000286
RAX: 0000000000000007 RBX: ffff8801976a07c0 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffff8801d9fe8950 RDI: 0000000000000246
RBP: ffff88010b157310 R08: ffff8801d9fe8970 R09: 069fa0192f184961
R10: ffff8801d9fe8000 R11: 0000000000000001 R12: ffff8801d9fe8000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
FS:  00007fc669a95700(0000) GS:ffff8801db600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f76dc47afda CR3: 000000017b006000 CR4: 00000000001606b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Stack:
 ffff8801976a0000
c dffffc0000000000
c ffff8801976a07c0
c ffff8801976a0738
c
 ffff88010b157330
c ffffffff82816c26
c ffffffff8141a061
c ffff8801976a0000
c
 ffff88010b157378
c ffffffff8141a061
c ffffffff81419f70
c ffffed0032ed40e7
c
Call Trace:
 [<ffffffff82816c26>] __raw_spin_lock include/linux/spinlock_api_smp.h:144 [inline]
 [<ffffffff82816c26>] _raw_spin_lock+0x36/0x50 kernel/locking/spinlock.c:151
 [<ffffffff8141a061>] spin_lock include/linux/spinlock.h:302 [inline]
 [<ffffffff8141a061>] task_lock include/linux/sched.h:3257 [inline]
 [<ffffffff8141a061>] find_lock_task_mm+0xf1/0x270 mm/oom_kill.c:115
 [<ffffffff821effdf>] lowmem_scan+0x34f/0xaf0 drivers/staging/android/lowmemorykiller.c:134
 [<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
 [<ffffffff814560c7>] shrink_zones mm/vmscan.c:2749 [inline]
 [<ffffffff814560c7>] do_try_to_free_pages mm/vmscan.c:2791 [inline]
 [<ffffffff814560c7>] try_to_free_pages+0x377/0xb80 mm/vmscan.c:3002
 [<ffffffff81428a01>] __perform_reclaim mm/page_alloc.c:3324 [inline]
 [<ffffffff81428a01>] __alloc_pages_direct_reclaim mm/page_alloc.c:3345 [inline]
 [<ffffffff81428a01>] __alloc_pages_slowpath mm/page_alloc.c:3697 [inline]
 [<ffffffff81428a01>] __alloc_pages_nodemask+0x981/0x1bd0 mm/page_alloc.c:3862
 [<ffffffff814c9e8b>] __alloc_pages include/linux/gfp.h:433 [inline]
 [<ffffffff814c9e8b>] __alloc_pages_node include/linux/gfp.h:446 [inline]
 [<ffffffff814c9e8b>] alloc_pages_node include/linux/gfp.h:460 [inline]
 [<ffffffff814c9e8b>] __vmalloc_area_node mm/vmalloc.c:1644 [inline]
 [<ffffffff814c9e8b>] __vmalloc_node_range+0x25b/0x600 mm/vmalloc.c:1702
 [<ffffffff814ca63b>] __vmalloc_node mm/vmalloc.c:1745 [inline]
 [<ffffffff814ca63b>] __vmalloc_node_flags mm/vmalloc.c:1759 [inline]
 [<ffffffff814ca63b>] vzalloc+0x5b/0x70 mm/vmalloc.c:1791
 [<ffffffff827cfbce>] alloc_one_pg_vec_page net/packet/af_packet.c:4208 [inline]
 [<ffffffff827cfbce>] alloc_pg_vec net/packet/af_packet.c:4233 [inline]
 [<ffffffff827cfbce>] packet_set_ring+0x51e/0x1810 net/packet/af_packet.c:4323
 [<ffffffff827d29d3>] packet_setsockopt+0xfa3/0x2630 net/packet/af_packet.c:3685
 [<ffffffff822a4d76>] SYSC_setsockopt net/socket.c:1785 [inline]
 [<ffffffff822a4d76>] SyS_setsockopt+0x166/0x260 net/socket.c:1764
 [<ffffffff810056ef>] do_syscall_64+0x19f/0x550 arch/x86/entry/common.c:285
 [<ffffffff82817893>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb
Code: 
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