Free memory is -12976kB above reserved
lowmemorykiller: Killing 'syz-executor3' (28730) (tgid 28714), adj 1000,
   to free 39100kB on behalf of 'syz-fuzzer' (2046) because
   cache -12172kB is below limit 6144kB for oom_score_adj 0
   Free memory is -12976kB above reserved
INFO: task syz-executor5:28711 blocked for more than 140 seconds.
      Not tainted 4.9.141+ #72
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor5   D30264 28711   2107 0x10000004
 ffff8801c4f04740 0000000000000000 ffff8801cc84a680 ffff8801a0efdf00
 ffff8801db721018 ffff88006d5ffad8 ffffffff82807952 ffff88006d5ffb58
 ffff8801c4f04740 ffffffff810efada 00fffc0000000000 ffff8801db7218f0
Call Trace:
 [<ffffffff82808e7f>] schedule+0x7f/0x1b0 kernel/sched/core.c:3553
 [<ffffffff822ad38c>] __lock_sock+0x13c/0x250 net/core/sock.c:2035
 [<ffffffff822ad596>] lock_sock_nested+0xf6/0x120 net/core/sock.c:2505
 [<ffffffff827d287f>] lock_sock include/net/sock.h:1404 [inline]
 [<ffffffff827d287f>] packet_setsockopt+0xabf/0x2630 net/packet/af_packet.c:3807
 [<ffffffff822a5106>] SYSC_setsockopt net/socket.c:1785 [inline]
 [<ffffffff822a5106>] SyS_setsockopt+0x166/0x260 net/socket.c:1764
 [<ffffffff810056ef>] do_syscall_64+0x19f/0x550 arch/x86/entry/common.c:285
 [<ffffffff82817c13>] 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: [<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/2021:
 #0:  (&tty->ldisc_sem){++++++}, at: [<ffffffff82815ce2>] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367
 #1:  (&ldata->atomic_read_lock){+.+.+.}, at: [<ffffffff81d376f2>] n_tty_read+0x202/0x16e0 drivers/tty/n_tty.c:2142
3 locks held by kworker/0:0/25512:
 #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: [<ffffffff82341667>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
1 lock held by syz-executor0/28720:
 #0:  (rtnl_mutex){+.+.+.}, at: [<ffffffff8234af7b>] rtnl_lock net/core/rtnetlink.c:70 [inline]
 #0:  (rtnl_mutex){+.+.+.}, at: [<ffffffff8234af7b>] rtnetlink_rcv+0x1b/0x40 net/core/rtnetlink.c:4083
1 lock held by syz-executor3/28730:
 #0:  (rtnl_mutex){+.+.+.}, at: [<ffffffff82341667>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
1 lock held by syz-executor4/28725:
 #0:  (rtnl_mutex){+.+.+.}, at: [<ffffffff82341667>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
1 lock held by syz-executor2/28726:
 #0:  (rtnl_mutex){+.+.+.}, at: [<ffffffff82341667>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70

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

NMI backtrace for cpu 1
CPU: 1 PID: 24 Comm: khungtaskd Not tainted 4.9.141+ #72
 ffff8801d9907d08 ffffffff81b43209 0000000000000000 0000000000000001
 0000000000000001 0000000000000001 ffffffff810983b0 ffff8801d9907d40
 ffffffff81b4e319 0000000000000001 0000000000000000 0000000000000003
Call Trace:
 [<ffffffff81b43209>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81b43209>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff81b4e319>] nmi_cpu_backtrace.cold.0+0x48/0x87 lib/nmi_backtrace.c:99
 [<ffffffff81b4e2ac>] 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
 [<ffffffff82817ddc>] 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: 28708 Comm: syz-executor5 Not tainted 4.9.141+ #72
task: ffff8801d2d2df00 task.stack: ffff8800b7cd8000
RIP: 0010:[<ffffffff8120cc1c>] 
c [<ffffffff8120cc1c>] lock_release+0x9c/0xc20 kernel/locking/lockdep.c:3773
RSP: 0018:ffff8800b7cdf288  EFLAGS: 00000807
RAX: ffff8801d2d2e7ac RBX: ffffffff830cc360 RCX: ffffc9000098f000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff8801d2d2e7ac
RBP: ffff8800b7cdf330 R08: ffff8801d2d2e870 R09: 9f21189aa22ea1a2
R10: 0000000000000000 R11: 0000000000000001 R12: ffff8801a120df00
R13: ffff8801d2d2df00 R14: ffff8801a120e6c0 R15: ffff8801a120e638
FS:  00007fdc85eb1700(0000) GS:ffff8801db600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000004236d0 CR3: 00000000a663a000 CR4: 00000000001606b0
DR0: 0000000020000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
Stack:
 0000000000000000
c 0000000000000000
c ffff8800b7cdf310
c 0000000000000246
c
 0000000000000000
c ffffffff8141a061
c ffff880000000000
c ffff8800b7cdf300
c
 ffffffff81ba810b
c ffffffff81419f70
c ffff8801a120df00
c 0000000000000246
c
Call Trace:
 [<ffffffff8141a0cb>] rcu_lock_release include/linux/rcupdate.h:498 [inline]
 [<ffffffff8141a0cb>] rcu_read_unlock include/linux/rcupdate.h:931 [inline]
 [<ffffffff8141a0cb>] find_lock_task_mm+0x15b/0x270 mm/oom_kill.c:122
 [<ffffffff821f036f>] 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
 [<ffffffff827cff5e>] alloc_one_pg_vec_page net/packet/af_packet.c:4208 [inline]
 [<ffffffff827cff5e>] alloc_pg_vec net/packet/af_packet.c:4233 [inline]
 [<ffffffff827cff5e>] packet_set_ring+0x51e/0x1810 net/packet/af_packet.c:4323
 [<ffffffff827d2d63>] packet_setsockopt+0xfa3/0x2630 net/packet/af_packet.c:3685
 [<ffffffff822a5106>] SYSC_setsockopt net/socket.c:1785 [inline]
 [<ffffffff822a5106>] SyS_setsockopt+0x166/0x260 net/socket.c:1764
 [<ffffffff810056ef>] do_syscall_64+0x19f/0x550 arch/x86/entry/common.c:285
 [<ffffffff82817c13>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb
Code: 
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c