BUG: unable to handle page fault for address: ffffffff7ef66200
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 8e70067 P4D 8e70067 PUD 0 
Oops: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 21 Comm: kworker/u4:1 Not tainted 5.3.0+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: writeback wb_workfn (flush-8:0)
RIP: 0010:variable_test_bit arch/x86/include/asm/bitops.h:214 [inline]
RIP: 0010:test_bit include/asm-generic/bitops-instrumented.h:238 [inline]
RIP: 0010:__lock_acquire+0x1575/0x4e70 kernel/locking/lockdep.c:3925
Code: 4c 89 9d 40 ff ff ff 49 8d 45 3f 4d 85 ed 4c 89 95 48 ff ff ff 49 0f 49 c5 48 c1 f8 06 48 8d 3c c5 60 89 77 8a e8 8b 3e 54 00 <4c> 0f a3 2d 13 20 1f 09 4c 8b 95 48 ff ff ff 4c 8b 9d 40 ff ff ff
RSP: 0018:ffff8880a9a3f938 EFLAGS: 00010046
RAX: 0000000000000001 RBX: 0000000000000000 RCX: ffffffff81586945
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff7ef66208
RBP: ffff8880a9a3fa48 R08: 1fffffffefdecc41 R09: fffffbffefdecc42
R10: fffffbffefdecc41 R11: ffffffff7ef6620f R12: a23c1e8ba3f6c51a
R13: ffffffffa3f6c51a R14: 0000000000000000 R15: 00000000000c051a
FS:  0000000000000000(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffff7ef66200 CR3: 000000006bafb000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
Call Trace:
 lock_acquire+0x190/0x410 kernel/locking/lockdep.c:4487
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0x95/0xcd kernel/locking/spinlock.c:159
 __wake_up_common_lock+0xc8/0x150 kernel/sched/wait.c:122
 __wake_up+0xe/0x10 kernel/sched/wait.c:142
 finish_writeback_work.isra.0+0xf6/0x120 fs/fs-writeback.c:168
 wb_do_writeback fs/fs-writeback.c:2030 [inline]
 wb_workfn+0x34f/0x11e0 fs/fs-writeback.c:2070
 process_one_work+0x9af/0x1740 kernel/workqueue.c:2269
 worker_thread+0x98/0xe40 kernel/workqueue.c:2415
 kthread+0x361/0x430 kernel/kthread.c:255
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
Modules linked in:
CR2: ffffffff7ef66200
---[ end trace 311cd2cfbc9dd6fe ]---
RIP: 0010:variable_test_bit arch/x86/include/asm/bitops.h:214 [inline]
RIP: 0010:test_bit include/asm-generic/bitops-instrumented.h:238 [inline]
RIP: 0010:__lock_acquire+0x1575/0x4e70 kernel/locking/lockdep.c:3925
Code: 4c 89 9d 40 ff ff ff 49 8d 45 3f 4d 85 ed 4c 89 95 48 ff ff ff 49 0f 49 c5 48 c1 f8 06 48 8d 3c c5 60 89 77 8a e8 8b 3e 54 00 <4c> 0f a3 2d 13 20 1f 09 4c 8b 95 48 ff ff ff 4c 8b 9d 40 ff ff ff
RSP: 0018:ffff8880a9a3f938 EFLAGS: 00010046
RAX: 0000000000000001 RBX: 0000000000000000 RCX: ffffffff81586945
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff7ef66208
RBP: ffff8880a9a3fa48 R08: 1fffffffefdecc41 R09: fffffbffefdecc42
R10: fffffbffefdecc41 R11: ffffffff7ef6620f R12: a23c1e8ba3f6c51a
R13: ffffffffa3f6c51a R14: 0000000000000000 R15: 00000000000c051a
FS:  0000000000000000(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffff7ef66200 CR3: 000000006bafb000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600