kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] SMP KASAN
Dumping ftrace buffer:
   (ftrace buffer empty)
Modules linked in:
CPU: 0 PID: 17021 Comm: udevd Not tainted 4.16.0+ #1
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:__delayacct_blkio_end+0x4f/0xc0 kernel/delayacct.c:82
RSP: 0018:ffff8801db006888 EFLAGS: 00010002
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffff8801a5934660
RDX: 0000000000000007 RSI: ffffffff8177ee11 RDI: 0000000000000038
RBP: ffff8801db0068a0 R08: ffffed003b6046c3 R09: 0000000000000001
R10: ffff8801db006930 R11: ffff8801db023613 R12: ffff8801a5b46400
R13: ffff8801a5934600 R14: ffff8801a5934664 R15: 0000000000000002
FS:  00007f4a08b077a0(0000) GS:ffff8801db000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffe1ec28dd0 CR3: 00000001bad86000 CR4: 00000000001406f0
DR0: 00000000200003c0 DR1: 00000000200003c0 DR2: 0000000020000000
DR3: 0000000020000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 delayacct_blkio_end include/linux/delayacct.h:128 [inline]
 try_to_wake_up+0xa9e/0x11b0 kernel/sched/core.c:2034
 default_wake_function+0x30/0x50 kernel/sched/core.c:3743
 autoremove_wake_function+0x7a/0x350 kernel/sched/wait.c:373
 wake_page_function+0x15f/0x1c0 mm/filemap.c:1009
 __wake_up_common+0x189/0x730 kernel/sched/wait.c:90
 __wake_up_locked_key_bookmark+0x16/0x20 kernel/sched/wait.c:165
 wake_up_page_bit+0x297/0x580 mm/filemap.c:1029
 wake_up_page mm/filemap.c:1070 [inline]
 end_page_writeback+0x24c/0x320 mm/filemap.c:1232
 ext4_finish_bio+0x593/0x940 fs/ext4/page-io.c:118
 ext4_end_bio+0x18f/0x6d0 fs/ext4/page-io.c:342
 bio_endio+0x4b8/0x920 block/bio.c:1775
 req_bio_endio block/blk-core.c:208 [inline]
 blk_update_request+0x3a3/0xcb0 block/blk-core.c:2990
 scsi_end_request+0xd3/0x870 drivers/scsi/scsi_lib.c:660
 scsi_io_completion+0xcb2/0x1a20 drivers/scsi/scsi_lib.c:868
 scsi_finish_command+0x542/0x8d0 drivers/scsi/scsi.c:248
 scsi_softirq_done+0x3d9/0x4b0 drivers/scsi/scsi_lib.c:1653
 __blk_mq_complete_request+0x4c8/0x9f0 block/blk-mq.c:559
 blk_mq_complete_request+0x2a5/0x370 block/blk-mq.c:644
 scsi_mq_done+0xe2/0x430 drivers/scsi/scsi_lib.c:1964
 virtscsi_complete_cmd+0x573/0x740 drivers/scsi/virtio_scsi.c:207
 virtscsi_vq_done+0xc3/0x170 drivers/scsi/virtio_scsi.c:223
 virtscsi_req_done+0xa7/0xd0 drivers/scsi/virtio_scsi.c:238
 vring_interrupt+0x128/0x170 drivers/virtio/virtio_ring.c:951
 __handle_irq_event_percpu+0x1c0/0xad0 kernel/irq/handle.c:147
 handle_irq_event_percpu+0x98/0x1c0 kernel/irq/handle.c:187
 handle_irq_event+0xa7/0x135 kernel/irq/handle.c:204
 handle_edge_irq+0x20f/0x870 kernel/irq/chip.c:793
 generic_handle_irq_desc include/linux/irqdesc.h:159 [inline]
 handle_irq+0x18c/0x2e7 arch/x86/kernel/irq_64.c:77
 do_IRQ+0x78/0x190 arch/x86/kernel/irq.c:238
 common_interrupt+0xf/0xf arch/x86/entry/entry_64.S:641
 </IRQ>
RIP: 0010:lock_is_held_type+0x42/0x210 kernel/locking/lockdep.c:3951
RSP: 0018:ffff88019e197b40 EFLAGS: 00000202 ORIG_RAX: ffffffffffffffda
RAX: 0000000000000007 RBX: ffff8801a5b46400 RCX: 1ffff10034b68d8d
RDX: 0000000000000000 RSI: 00000000ffffffff RDI: ffff8801a5b46c74
RBP: ffff88019e197b60 R08: 1ffff10033c32f65 R09: ffff88019e197968
R10: 0000000000000003 R11: 0000000000000000 R12: 0000000000000000
R13: ffffffff88b90ce0 R14: 00000000000001a4 R15: 00000000014000c0
 lock_is_held include/linux/lockdep.h:344 [inline]
 rcu_preempt_sleep_check include/linux/rcupdate.h:303 [inline]
 ___might_sleep+0x246/0x320 kernel/sched/core.c:6152
 __might_sleep+0x95/0x190 kernel/sched/core.c:6140
 slab_pre_alloc_hook mm/slab.h:420 [inline]
 slab_alloc mm/slab.c:3366 [inline]
 kmem_cache_alloc+0x2a0/0x760 mm/slab.c:3540
 getname_flags+0xd0/0x5a0 fs/namei.c:138
 getname+0x19/0x20 fs/namei.c:209
 do_sys_open+0x39a/0x740 fs/open.c:1095
 SYSC_open fs/open.c:1119 [inline]
 SyS_open+0x2d/0x40 fs/open.c:1114
 do_syscall_64+0x29e/0x9d0 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x7f4a0820f120
RSP: 002b:00007ffe1ec28e38 EFLAGS: 00000246 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 0000000000a594d0 RCX: 00007f4a0820f120
RDX: 00000000000001b6 RSI: 0000000000080241 RDI: 00007ffe1ec29320
RBP: 00007ffe1ec28eb0 R08: 0000000000000004 R09: 0000000000000001
R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000004
R13: 0000000000420721 R14: 00007ffe1ec28f20 R15: 0000000000000000
Code: fa 48 c1 ea 03 80 3c 02 00 0f 85 80 00 00 00 48 8b 9b 70 12 00 00 48 b8 00 00 00 00 00 fc ff df 48 8d 7b 38 48 89 fa 48 c1 ea 03 <0f> b6 04 02 84 c0 74 04 3c 03 7e 51 44 8b 63 38 31 ff 41 83 e4 
RIP: __delayacct_blkio_end+0x4f/0xc0 kernel/delayacct.c:82 RSP: ffff8801db006888

======================================================
WARNING: possible circular locking dependency detected
4.16.0+ #1 Not tainted
------------------------------------------------------
udevd/17021 is trying to acquire lock:
000000009847d2c0 ((console_sem).lock){-...}, at: down_trylock+0x13/0x70 kernel/locking/semaphore.c:136

but task is already holding lock:
000000005a9f89f3 (&p->pi_lock){-.-.}, at: try_to_wake_up+0xca/0x11b0 kernel/sched/core.c:1963

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&p->pi_lock){-.-.}:
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0x96/0xc0 kernel/locking/spinlock.c:152
       try_to_wake_up+0xca/0x11b0 kernel/sched/core.c:1963
       wake_up_process+0x10/0x20 kernel/sched/core.c:2126
       __up.isra.1+0x1b8/0x290 kernel/locking/semaphore.c:262
       up+0x12f/0x1b0 kernel/locking/semaphore.c:187
       __up_console_sem+0xbe/0x1b0 kernel/printk/printk.c:242
       console_unlock+0x7d6/0x1100 kernel/printk/printk.c:2417
       do_con_write+0x12b2/0x2280 drivers/tty/vt/vt.c:2433
       con_write+0x25/0xc0 drivers/tty/vt/vt.c:2782
       process_output_block drivers/tty/n_tty.c:579 [inline]
       n_tty_write+0x6b9/0x1180 drivers/tty/n_tty.c:2308
       do_tty_write drivers/tty/tty_io.c:958 [inline]
       tty_write+0x3f1/0x880 drivers/tty/tty_io.c:1042
       __vfs_write+0x10b/0x880 fs/read_write.c:485
       vfs_write+0x1f8/0x560 fs/read_write.c:549
       ksys_write+0xf9/0x250 fs/read_write.c:598
       SYSC_write fs/read_write.c:610 [inline]
       SyS_write+0x24/0x30 fs/read_write.c:607
       do_syscall_64+0x29e/0x9d0 arch/x86/entry/common.c:287
       entry_SYSCALL_64_after_hwframe+0x42/0xb7

-> #0 ((console_sem).lock){-...}:
       lock_acquire+0x1dc/0x520 kernel/locking/lockdep.c:3920
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0x96/0xc0 kernel/locking/spinlock.c:152
       down_trylock+0x13/0x70 kernel/locking/semaphore.c:136
       __down_trylock_console_sem+0xae/0x200 kernel/printk/printk.c:225
       console_trylock+0x15/0xa0 kernel/printk/printk.c:2229
       console_trylock_spinning kernel/printk/printk.c:1643 [inline]
       vprintk_emit+0x694/0xdd0 kernel/printk/printk.c:1906
       vprintk_default+0x28/0x30 kernel/printk/printk.c:1947
       vprintk_func+0x7a/0xe7 kernel/printk/printk_safe.c:379
       printk+0x9e/0xba kernel/printk/printk.c:1980
       kasan_die_handler.cold.22+0x11/0x30 arch/x86/mm/kasan_init_64.c:253
       notifier_call_chain+0x178/0x380 kernel/notifier.c:93
       __atomic_notifier_call_chain kernel/notifier.c:183 [inline]
       atomic_notifier_call_chain+0x98/0x190 kernel/notifier.c:193
       notify_die+0x1a3/0x2b0 kernel/notifier.c:549
       do_general_protection+0x248/0x2f0 arch/x86/kernel/traps.c:558
       general_protection+0x25/0x50 arch/x86/entry/entry_64.S:1155
       __delayacct_blkio_end+0x4f/0xc0 kernel/delayacct.c:82
       delayacct_blkio_end include/linux/delayacct.h:128 [inline]
       try_to_wake_up+0xa9e/0x11b0 kernel/sched/core.c:2034
       default_wake_function+0x30/0x50 kernel/sched/core.c:3743
       autoremove_wake_function+0x7a/0x350 kernel/sched/wait.c:373
       wake_page_function+0x15f/0x1c0 mm/filemap.c:1009
       __wake_up_common+0x189/0x730 kernel/sched/wait.c:90
       __wake_up_locked_key_bookmark+0x16/0x20 kernel/sched/wait.c:165
       wake_up_page_bit+0x297/0x580 mm/filemap.c:1029
       wake_up_page mm/filemap.c:1070 [inline]
       end_page_writeback+0x24c/0x320 mm/filemap.c:1232
       ext4_finish_bio+0x593/0x940 fs/ext4/page-io.c:118
       ext4_end_bio+0x18f/0x6d0 fs/ext4/page-io.c:342
       bio_endio+0x4b8/0x920 block/bio.c:1775
       req_bio_endio block/blk-core.c:208 [inline]
       blk_update_request+0x3a3/0xcb0 block/blk-core.c:2990
       scsi_end_request+0xd3/0x870 drivers/scsi/scsi_lib.c:660
       scsi_io_completion+0xcb2/0x1a20 drivers/scsi/scsi_lib.c:868
       scsi_finish_command+0x542/0x8d0 drivers/scsi/scsi.c:248
       scsi_softirq_done+0x3d9/0x4b0 drivers/scsi/scsi_lib.c:1653
       __blk_mq_complete_request+0x4c8/0x9f0 block/blk-mq.c:559
       blk_mq_complete_request+0x2a5/0x370 block/blk-mq.c:644
       scsi_mq_done+0xe2/0x430 drivers/scsi/scsi_lib.c:1964
       virtscsi_complete_cmd+0x573/0x740 drivers/scsi/virtio_scsi.c:207
       virtscsi_vq_done+0xc3/0x170 drivers/scsi/virtio_scsi.c:223
       virtscsi_req_done+0xa7/0xd0 drivers/scsi/virtio_scsi.c:238
       vring_interrupt+0x128/0x170 drivers/virtio/virtio_ring.c:951
       __handle_irq_event_percpu+0x1c0/0xad0 kernel/irq/handle.c:147
       handle_irq_event_percpu+0x98/0x1c0 kernel/irq/handle.c:187
       handle_irq_event+0xa7/0x135 kernel/irq/handle.c:204
       handle_edge_irq+0x20f/0x870 kernel/irq/chip.c:793
       generic_handle_irq_desc include/linux/irqdesc.h:159 [inline]
       handle_irq+0x18c/0x2e7 arch/x86/kernel/irq_64.c:77
       do_IRQ+0x78/0x190 arch/x86/kernel/irq.c:238
       ret_from_intr+0x0/0x1e
       lock_is_held_type+0x42/0x210 kernel/locking/lockdep.c:3951
       lock_is_held include/linux/lockdep.h:344 [inline]
       rcu_preempt_sleep_check include/linux/rcupdate.h:303 [inline]
       ___might_sleep+0x246/0x320 kernel/sched/core.c:6152
       __might_sleep+0x95/0x190 kernel/sched/core.c:6140
       slab_pre_alloc_hook mm/slab.h:420 [inline]
       slab_alloc mm/slab.c:3366 [inline]
       kmem_cache_alloc+0x2a0/0x760 mm/slab.c:3540
       getname_flags+0xd0/0x5a0 fs/namei.c:138
       getname+0x19/0x20 fs/namei.c:209
       do_sys_open+0x39a/0x740 fs/open.c:1095
       SYSC_open fs/open.c:1119 [inline]
       SyS_open+0x2d/0x40 fs/open.c:1114
       do_syscall_64+0x29e/0x9d0 arch/x86/entry/common.c:287
       entry_SYSCALL_64_after_hwframe+0x42/0xb7

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&p->pi_lock);
                               lock((console_sem).lock);
                               lock(&p->pi_lock);
  lock((console_sem).lock);

 *** DEADLOCK ***

5 locks held by udevd/17021:
 #0: 0000000022114d85 (&(&virtscsi_vq->vq_lock)->rlock){-.-.}, at: virtscsi_vq_done+0x9d/0x170 drivers/scsi/virtio_scsi.c:219
 #1: 0000000041d7bb96 (rcu_read_lock){....}, at: hctx_lock+0x7a/0x1d0 block/blk-mq.c:578
 #2: 0000000033f08fe1 (&page_wait_table[i]){-.-.}, at: wake_up_page_bit+0x27d/0x580 mm/filemap.c:1028
 #3: 000000005a9f89f3 (&p->pi_lock){-.-.}, at: try_to_wake_up+0xca/0x11b0 kernel/sched/core.c:1963
 #4: 0000000041d7bb96 (rcu_read_lock){....}, at: atomic_notifier_call_chain+0x0/0x190 include/linux/compiler.h:188

stack backtrace:
CPU: 0 PID: 17021 Comm: udevd Not tainted 4.16.0+ #1
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x1b9/0x29f lib/dump_stack.c:53
 print_circular_bug.isra.36.cold.54+0x1bd/0x27d kernel/locking/lockdep.c:1223
 check_prev_add kernel/locking/lockdep.c:1863 [inline]
 check_prevs_add kernel/locking/lockdep.c:1976 [inline]
 validate_chain kernel/locking/lockdep.c:2417 [inline]
 __lock_acquire+0x343e/0x5140 kernel/locking/lockdep.c:3431
 lock_acquire+0x1dc/0x520 kernel/locking/lockdep.c:3920
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0x96/0xc0 kernel/locking/spinlock.c:152
 down_trylock+0x13/0x70 kernel/locking/semaphore.c:136
 __down_trylock_console_sem+0xae/0x200 kernel/printk/printk.c:225
 console_trylock+0x15/0xa0 kernel/printk/printk.c:2229
 console_trylock_spinning kernel/printk/printk.c:1643 [inline]
 vprintk_emit+0x694/0xdd0 kernel/printk/printk.c:1906
 vprintk_default+0x28/0x30 kernel/printk/printk.c:1947
 vprintk_func+0x7a/0xe7 kernel/printk/printk_safe.c:379
 printk+0x9e/0xba kernel/printk/printk.c:1980
 kasan_die_handler.cold.22+0x11/0x30 arch/x86/mm/kasan_init_64.c:253
 notifier_call_chain+0x178/0x380 kernel/notifier.c:93
 __atomic_notifier_call_chain kernel/notifier.c:183 [inline]
 atomic_notifier_call_chain+0x98/0x190 kernel/notifier.c:193
 notify_die+0x1a3/0x2b0 kernel/notifier.c:549
 do_general_protection+0x248/0x2f0 arch/x86/kernel/traps.c:558
 general_protection+0x25/0x50 arch/x86/entry/entry_64.S:1155
RIP: 0010:__delayacct_blkio_end+0x4f/0xc0 kernel/delayacct.c:82
RSP: 0018:ffff8801db006888 EFLAGS: 00010002
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffff8801a5934660
RDX: 0000000000000007 RSI: ffffffff8177ee11 RDI: 0000000000000038
RBP: ffff8801db0068a0 R08: ffffed003b6046c3 R09: 0000000000000001
R10: ffff8801db006930 R11: ffff8801db023613 R12: ffff8801a5b46400
R13: ffff8801a5934600 R14: ffff8801a5934664 R15: 0000000000000002
 delayacct_blkio_end include/linux/delayacct.h:128 [inline]
 try_to_wake_up+0xa9e/0x11b0 kernel/sched/core.c:2034
 default_wake_function+0x30/0x50 kernel/sched/core.c:3743
 autoremove_wake_function+0x7a/0x350 kernel/sched/wait.c:373
 wake_page_function+0x15f/0x1c0 mm/filemap.c:1009
 __wake_up_common+0x189/0x730 kernel/sched/wait.c:90
 __wake_up_locked_key_bookmark+0x16/0x20 kernel/sched/wait.c:165
 wake_up_page_bit+0x297/0x580 mm/filemap.c:1029
 wake_up_page mm/filemap.c:1070 [inline]
 end_page_writeback+0x24c/0x320 mm/filemap.c:1232
 ext4_finish_bio+0x593/0x940 fs/ext4/page-io.c:118
 ext4_end_bio+0x18f/0x6d0 fs/ext4/page-io.c:342
 ? ext4_put_io_end_def
Lost 110 message(s)!
---[ end trace f2eb6bd6466cab58 ]---