RBP: 000000000072bea0 R08: 00000000200d5000 R09: 0000000000000000
R10: 0000000020f8b000 R11: 0000000000000246 R12: 0000000000000015
R13: 0000000000000051 R14: 00000000006f3838 R15: 0000000000000002
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: 4574 Comm: syz-executor6 Not tainted 4.17.0-rc1+ #6
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: 0000:ffff8801db006888 EFLAGS: 00010002
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffff88018a2d0038
RDX: 0000000000000007 RSI: ffffffff817a3b51 RDI: 0000000000000038
RBP: ffff8801db0068a0 R08: ffffed003b6046c3 R09: 0000000000000001
R10: ffff8801db006930 R11: ffff8801db023613 R12: ffff880190744400
R13: ffff88018a2d0000 R14: ffff88018a2d003c R15: 0000000000000002
FS:  00000000011ce940(0000) GS:ffff8801db000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000093002d CR3: 0000000190722000 CR4: 00000000001406f0
DR0: 0000000020000000 DR1: 0000000020000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 delayacct_blkio_end include/linux/delayacct.h:128 [inline]
 try_to_wake_up+0xa89/0x1190 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:1010
 __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:1030
 wake_up_page mm/filemap.c:1071 [inline]
 end_page_writeback+0x24c/0x320 mm/filemap.c:1233
 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:280 [inline]
 blk_update_request+0x3a3/0xcb0 block/blk-core.c:3099
 scsi_end_request+0xd3/0x870 drivers/scsi/scsi_lib.c:672
 scsi_io_completion+0xca9/0x1d10 drivers/scsi/scsi_lib.c:898
 scsi_finish_command+0x542/0x8d0 drivers/scsi/scsi.c:248
 scsi_softirq_done+0x3d9/0x4b0 drivers/scsi/scsi_lib.c:1683
 __blk_mq_complete_request+0x4c8/0x9f0 block/blk-mq.c:551
 blk_mq_complete_request+0x2a5/0x370 block/blk-mq.c:636
 scsi_mq_done+0xe2/0x430 drivers/scsi/scsi_lib.c:1994
 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:950
 __handle_irq_event_percpu+0x1c0/0xad0 kernel/irq/handle.c:149
 handle_irq_event_percpu+0x98/0x1c0 kernel/irq/handle.c:189
 handle_irq_event+0xa7/0x135 kernel/irq/handle.c:206
 handle_edge_irq+0x20f/0x870 kernel/irq/chip.c:791
 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:245
 common_interrupt+0xf/0xf arch/x86/entry/entry_64.S:642
 </IRQ>
RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:783 [inline]
RIP: 0010:count_memcg_events include/linux/memcontrol.h:677 [inline]
RIP: 0010:count_memcg_event_mm include/linux/memcontrol.h:698 [inline]
RIP: 0010:handle_mm_fault+0x8fa/0xc70 mm/memory.c:4104
RSP: 0000:ffff88019076fc50 EFLAGS: 00000293 ORIG_RAX: ffffffffffffffda
RAX: ffff880190744400 RBX: 1ffff100320edf8e RCX: 1ffff100320e898b
RDX: 0000000000000000 RSI: ffffffff81a7fc05 RDI: 0000000000000293
RBP: ffff88019076fcf8 R08: ffff880190744c38 R09: 0000000000000006
R10: ffff880190744400 R11: 0000000000000000 R12: ffff8801aee2a318
R13: 0000000000000200 R14: 0000000000000055 R15: 0000000000000293
 __do_page_fault+0x60b/0xe40 arch/x86/mm/fault.c:1399
 do_page_fault+0xee/0x8a7 arch/x86/mm/fault.c:1474
 page_fault+0x1e/0x30 arch/x86/entry/entry_64.S:1160
RIP: 0033:0x4071e8
RSP: 002b:00007fff6e3b4e98 EFLAGS: 00010246
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 000000000040f380
RDX: 0000000000000038 RSI: 0000000000000000 RDI: 00000000000000f2
RBP: 0000000000000013 R08: 0000000000000000 R09: 000000000000000a
R10: 0000000000000075 R11: 0000000000000246 R12: 0000000000000013
R13: 0000000000000000 R14: 00000000006fe800 R15: 0000000000001380
Code: fa 48 c1 ea 03 80 3c 02 00 0f 85 80 00 00 00 48 8b 9b 30 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
4.17.0-rc1+ #6 Not tainted
------------------------------------------------------
syz-executor6/4574 is trying to acquire lock:
00000000aab1a832 ((console_sem).lock){-.-.}, at: down_trylock+0x13/0x70 kernel/locking/semaphore.c:136

but task is already holding lock:
0000000023c0ecad (&p->pi_lock){-.-.}, at: try_to_wake_up+0xca/0x1190 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/0x1190 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:2437
       con_write+0x25/0xc0 drivers/tty/vt/vt.c:2786
       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
       __do_sys_write fs/read_write.c:610 [inline]
       __se_sys_write fs/read_write.c:607 [inline]
       __x64_sys_write+0x73/0xb0 fs/read_write.c:607
       do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287
       entry_SYSCALL_64_after_hwframe+0x49/0xbe

-> #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+0x1e/0x30 arch/x86/entry/entry_64.S:1159
       __delayacct_blkio_end+0x4f/0xc0 kernel/delayacct.c:82
       delayacct_blkio_end include/linux/delayacct.h:128 [inline]
       try_to_wake_up+0xa89/0x1190 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:1010
       __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:1030
       wake_up_page mm/filemap.c:1071 [inline]
       end_page_writeback+0x24c/0x320 mm/filemap.c:1233
       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:280 [inline]
       blk_update_request+0x3a3/0xcb0 block/blk-core.c:3099
       scsi_end_request+0xd3/0x870 drivers/scsi/scsi_lib.c:672
       scsi_io_completion+0xca9/0x1d10 drivers/scsi/scsi_lib.c:898
       scsi_finish_command+0x542/0x8d0 drivers/scsi/scsi.c:248
       scsi_softirq_done+0x3d9/0x4b0 drivers/scsi/scsi_lib.c:1683
       __blk_mq_complete_request+0x4c8/0x9f0 block/blk-mq.c:551
       blk_mq_complete_request+0x2a5/0x370 block/blk-mq.c:636
       scsi_mq_done+0xe2/0x430 drivers/scsi/scsi_lib.c:1994
       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:950
       __handle_irq_event_percpu+0x1c0/0xad0 kernel/irq/handle.c:149
       handle_irq_event_percpu+0x98/0x1c0 kernel/irq/handle.c:189
       handle_irq_event+0xa7/0x135 kernel/irq/handle.c:206
       handle_edge_irq+0x20f/0x870 kernel/irq/chip.c:791
       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:245
       ret_from_intr+0x0/0x1e
       arch_local_irq_restore arch/x86/include/asm/paravirt.h:783 [inline]
       count_memcg_events include/linux/memcontrol.h:677 [inline]
       count_memcg_event_mm include/linux/memcontrol.h:698 [inline]
       handle_mm_fault+0x8fa/0xc70 mm/memory.c:4104
       __do_page_fault+0x60b/0xe40 arch/x86/mm/fault.c:1399
       do_page_fault+0xee/0x8a7 arch/x86/mm/fault.c:1474
       page_fault+0x1e/0x30 arch/x86/entry/entry_64.S:1160

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 ***

7 locks held by syz-executor6/4574:
 #0: 00000000b080687c (&mm->mmap_sem){++++}, at: __do_page_fault+0x381/0xe40 arch/x86/mm/fault.c:1328
 #1: 00000000dc90722c (rcu_read_lock){....}, at: handle_mm_fault+0x107/0xc70 mm/memory.c:4104
 #2: 00000000d3c0eab0 (&(&virtscsi_vq->vq_lock)->rlock){-.-.}, at: virtscsi_vq_done+0x9d/0x170 drivers/scsi/virtio_scsi.c:219
 #3: 00000000dc90722c (rcu_read_lock){....}, at: hctx_lock+0x7a/0x1d0 block/blk-mq.c:570
 #4: 00000000737bd99d (&page_wait_table[i]){-.-.}, at: wake_up_page_bit+0x27d/0x580 mm/filemap.c:1029
 #5: 0000000023c0ecad (&p->pi_lock){-.-.}, at: try_to_wake_up+0xca/0x1190 kernel/sched/core.c:1963
 #6: 00000000dc90722c (rcu_read_lock){....}, at: atomic_notifier_call_chain+0x0/0x190 include/linux/compiler.h:188

stack backtrace:
CPU: 0 PID: 4574 Comm: syz-executor6 Not tainted 4.17.0-rc1+ #6
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1b9/0x294 lib/dump_stack.c:113
 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+0x1e/0x30 arch/x86/entry/entry_64.S:1159
RIP: 0010:__delayacct_blkio_end+0x4f/0xc0 kernel/delayacct.c:82
RSP: 0000:ffff8801db006888 EFLAGS: 00010002
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffff88018a2d0038
RDX: 0000000000000007 RSI: ffffffff817a3b51 RDI: 0000000000000038
RBP: ffff8801db0068a0 R08: ffffed003b6046c3 R09: 0000000000000001
R10: ffff8801db006930 R11: ffff8801db023613 R12: ffff880190744400
R13: ffff88018a2d0000 R14: ffff88018a2d003c R15: 0000000000000002
 delayacct_blkio_end include/linux/delayacct.h:128 [inline]
 try_to_wake_up+0xa89/0x1190 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:1010
 __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:1030
 wake_up_page mm/filemap.c:1071 [inline]
 end_page_writeback+0x24c/0x320 mm/filemap.c:1233
 ext4_finish_bio+0x593/0x940 fs/ext4/page-io.c:118
 ext4_end_bio+0x18f/0x6d0 fs/ext4/page-io.c:342
Lost 115 message(s)!
---[ end trace c4e907980e07a058 ]---