=====================================
WARNING: bad unlock balance detected!
syzkaller #0 Not tainted
-------------------------------------
dhcpcd-run-hook/5582 is trying to release lock (rcu_read_lock) at:
[<ffffffff82193a9b>] do_pte_missing+0x125b/0x33f0
but there are no more locks to release!

other info that might help us debug this:
1 lock held by dhcpcd-run-hook/5582:
 #0: ffff8881104f5d08 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0x1d1/0x500

stack backtrace:
CPU: 0 UID: 0 PID: 5582 Comm: dhcpcd-run-hook Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150
 print_unlock_imbalance_bug+0xdc/0xf0
 lock_release+0x248/0x3c0
 do_pte_missing+0x1fc4/0x33f0
 handle_mm_fault+0x1bd7/0x3170
 do_user_addr_fault+0xa73/0x1340
 exc_page_fault+0x6a/0xc0
 asm_exc_page_fault+0x26/0x30
RIP: 0033:0x7fa176079bf5
Code: 00 00 00 00 00 49 89 c0 4c 8d 68 ff 48 8b 85 a0 fd ff ff 49 c7 87 58 03 00 00 ff ff ff ff 49 f7 d8 48 39 d8 0f 83 05 02 00 00 <8b> 10 83 fa 07 77 1c 85 d2 0f 84 c5 01 00 00 ff ca 83 fa 06 0f 87
RSP: 002b:00007ffdc6ae7b80 EFLAGS: 00010297
RAX: 0000564e49480040 RBX: 0000564e49480318 RCX: 00007fa176088958
RDX: 0000000000000692 RSI: 00007fa176086bb6 RDI: 0000000000000000
RBP: 00007ffdc6ae7e20 R08: fffffffffffff000 R09: 00007fa176082cdc
R10: 00007fa176091240 R11: 00007fa176091220 R12: 0000000000000000
R13: 0000000000000fff R14: 0000000000000000 R15: 00007fa1760912a0
 </TASK>
------------[ cut here ]------------
rrln < 0 || rrln > RCU_NEST_PMAX
WARNING: kernel/rcu/tree_plugin.h:443 at __rcu_read_unlock+0x79/0xe0, CPU#0: dhcpcd-run-hook/5582
Modules linked in:
CPU: 0 UID: 0 PID: 5582 Comm: dhcpcd-run-hook Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:__rcu_read_unlock+0x79/0xe0
Code: 75 66 41 83 3e 00 75 27 43 0f b6 04 3c 84 c0 75 41 8b 03 3d 00 00 00 40 73 0f 5b 41 5c 41 5d 41 5e 41 5f c3 cc cc cc cc cc 90 <0f> 0b 90 eb eb e8 6d 00 00 00 eb d2 89 d9 80 e1 07 80 c1 03 38 c1
RSP: 0000:ffffc90004627b10 EFLAGS: 00010286
RAX: 00000000ffffffff RBX: ffff888172a3bfc4 RCX: 0000000000000046
RDX: 0000000000000000 RSI: ffffffff8e217007 RDI: ffff888172a3bb00
RBP: 0000000000000000 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffffbfff1d06d14 R12: 1ffff1102e5477f8
R13: 0000000000000100 R14: 0000000000000000 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff88818dc93000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000564e49480040 CR3: 0000000111282000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 do_pte_missing+0x1fc9/0x33f0
 handle_mm_fault+0x1bd7/0x3170
 do_user_addr_fault+0xa73/0x1340
 exc_page_fault+0x6a/0xc0
 asm_exc_page_fault+0x26/0x30
RIP: 0033:0x7fa176079bf5
Code: 00 00 00 00 00 49 89 c0 4c 8d 68 ff 48 8b 85 a0 fd ff ff 49 c7 87 58 03 00 00 ff ff ff ff 49 f7 d8 48 39 d8 0f 83 05 02 00 00 <8b> 10 83 fa 07 77 1c 85 d2 0f 84 c5 01 00 00 ff ca 83 fa 06 0f 87
RSP: 002b:00007ffdc6ae7b80 EFLAGS: 00010297
RAX: 0000564e49480040 RBX: 0000564e49480318 RCX: 00007fa176088958
RDX: 0000000000000692 RSI: 00007fa176086bb6 RDI: 0000000000000000
RBP: 00007ffdc6ae7e20 R08: fffffffffffff000 R09: 00007fa176082cdc
R10: 00007fa176091240 R11: 00007fa176091220 R12: 0000000000000000
R13: 0000000000000fff R14: 0000000000000000 R15: 00007fa1760912a0
 </TASK>
