FAULT_INJECTION: forcing a failure.
name fail_usercopy, interval 1, probability 0, space 0, times 0
======================================================
WARNING: possible circular locking dependency detected
6.17.0-rc1-syzkaller-00116-gd7ee5bdce789 #0 Not tainted
------------------------------------------------------
syz.3.1305/11258 is trying to acquire lock:
ffffffff8e12e120 (console_owner){-.-.}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:336 [inline]
ffffffff8e12e120 (console_owner){-.-.}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:319 [inline]
ffffffff8e12e120 (console_owner){-.-.}-{0:0}, at: console_srcu_read_lock kernel/printk/printk.c:288 [inline]
ffffffff8e12e120 (console_owner){-.-.}-{0:0}, at: console_flush_all+0x13a/0xc40 kernel/printk/printk.c:3203

but task is already holding lock:
ffff8880b8639f98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:636

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #5 (&rq->__lock){-.-.}-{2:2}:
       lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
       _raw_spin_lock_nested+0x32/0x50 kernel/locking/spinlock.c:378
       raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:636
       raw_spin_rq_lock kernel/sched/sched.h:1519 [inline]
       task_rq_lock+0xbc/0x470 kernel/sched/core.c:736
       cgroup_move_task+0x92/0x2a0 kernel/sched/psi.c:1170
       css_set_move_task+0x658/0x9e0 kernel/cgroup/cgroup.c:918
       cgroup_post_fork+0x1ef/0x790 kernel/cgroup/cgroup.c:6759
       copy_process+0x3862/0x3c00 kernel/fork.c:2419
       kernel_clone+0x21e/0x840 kernel/fork.c:2605
       user_mode_thread+0xdd/0x140 kernel/fork.c:2683
       rest_init+0x23/0x300 init/main.c:709
       start_kernel+0x3a9/0x410 init/main.c:1097
       x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:307
       x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:288
       common_startup_64+0x13e/0x147

-> #4 (&p->pi_lock){-.-.}-{2:2}:
       lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0xa7/0xf0 kernel/locking/spinlock.c:162
       class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:557 [inline]
       try_to_wake_up+0x67/0x12b0 kernel/sched/core.c:4216
       create_worker+0x503/0x720 kernel/workqueue.c:2832
       workqueue_init+0x3f0/0x6a0 kernel/workqueue.c:7918
       kernel_init_freeable+0x302/0x4b0 init/main.c:1564
       kernel_init+0x1d/0x1d0 init/main.c:1469
       ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

-> #3 (&pool->lock){-.-.}-{2:2}:
       lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
       __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
       _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
       __queue_work+0x809/0xfb0 kernel/workqueue.c:-1
       queue_work_on+0x181/0x270 kernel/workqueue.c:2390
       queue_work include/linux/workqueue.h:669 [inline]
       rpm_suspend+0xe54/0x1720 drivers/base/power/runtime.c:685
       __pm_runtime_idle+0x12f/0x1a0 drivers/base/power/runtime.c:1124
       pm_runtime_put include/linux/pm_runtime.h:555 [inline]
       __device_attach+0x342/0x400 drivers/base/dd.c:1049
       bus_probe_device+0x185/0x260 drivers/base/bus.c:537
       device_add+0x7b6/0xb50 drivers/base/core.c:3689
       serial_base_port_add+0x2e3/0x410 drivers/tty/serial/serial_base_bus.c:183
       serial_core_port_device_add drivers/tty/serial/serial_core.c:3309 [inline]
       serial_core_register_port+0x369/0x27c0 drivers/tty/serial/serial_core.c:3348
       serial8250_register_8250_port+0x16db/0x2050 drivers/tty/serial/8250/8250_core.c:829
       serial_pnp_probe+0x527/0x790 drivers/tty/serial/8250/8250_pnp.c:480
       pnp_device_probe+0x30b/0x4c0 drivers/pnp/driver.c:111
       call_driver_probe drivers/base/dd.c:-1 [inline]
       really_probe+0x26d/0x9e0 drivers/base/dd.c:659
       __driver_probe_device+0x18c/0x2f0 drivers/base/dd.c:801
       driver_probe_device+0x4f/0x430 drivers/base/dd.c:831
       __driver_attach+0x452/0x700 drivers/base/dd.c:1217
       bus_for_each_dev+0x233/0x2b0 drivers/base/bus.c:370
       bus_add_driver+0x345/0x640 drivers/base/bus.c:678
       driver_register+0x23a/0x320 drivers/base/driver.c:249
       serial8250_init+0x8f/0x160 drivers/tty/serial/8250/8250_platform.c:315
       do_one_initcall+0x236/0x820 init/main.c:1269
       do_initcall_level+0x104/0x190 init/main.c:1331
       do_initcalls+0x59/0xa0 init/main.c:1347
       kernel_init_freeable+0x334/0x4b0 init/main.c:1579
       kernel_init+0x1d/0x1d0 init/main.c:1469
       ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

-> #2 (&dev->power.lock){-...}-{3:3}:
       lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0xa7/0xf0 kernel/locking/spinlock.c:162
       __pm_runtime_resume+0x10f/0x180 drivers/base/power/runtime.c:1191
       pm_runtime_get include/linux/pm_runtime.h:492 [inline]
       __uart_start+0x171/0x460 drivers/tty/serial/serial_core.c:149
       uart_write+0xdc/0x130 drivers/tty/serial/serial_core.c:636
       process_output_block drivers/tty/n_tty.c:561 [inline]
       n_tty_write+0xd2c/0x1200 drivers/tty/n_tty.c:2377
       iterate_tty_write drivers/tty/tty_io.c:1006 [inline]
       file_tty_write+0x554/0xa20 drivers/tty/tty_io.c:1081
       new_sync_write fs/read_write.c:593 [inline]
       vfs_write+0x5c9/0xb30 fs/read_write.c:686
       ksys_write+0x145/0x250 fs/read_write.c:738
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #1 (&port_lock_key){-.-.}-{3:3}:
       lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0xa7/0xf0 kernel/locking/spinlock.c:162
       uart_port_lock_irqsave include/linux/serial_core.h:717 [inline]
       serial8250_console_write+0x17e/0x1ba0 drivers/tty/serial/8250/8250_port.c:3355
       console_emit_next_record kernel/printk/printk.c:3138 [inline]
       console_flush_all+0x728/0xc40 kernel/printk/printk.c:3226
       __console_flush_and_unlock kernel/printk/printk.c:3285 [inline]
       console_unlock+0xc4/0x270 kernel/printk/printk.c:3325
       vprintk_emit+0x5b7/0x7a0 kernel/printk/printk.c:2450
       _printk+0xcf/0x120 kernel/printk/printk.c:2475
       register_console+0xa8b/0xf90 kernel/printk/printk.c:4126
       univ8250_console_init+0x3a/0x70 drivers/tty/serial/8250/8250_core.c:516
       console_init+0x10e/0x430 kernel/printk/printk.c:4325
       start_kernel+0x254/0x410 init/main.c:1035
       x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:307
       x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:288
       common_startup_64+0x13e/0x147

-> #0 (console_owner){-.-.}-{0:0}:
       check_prev_add kernel/locking/lockdep.c:3165 [inline]
       check_prevs_add kernel/locking/lockdep.c:3284 [inline]
       validate_chain+0xb9b/0x2140 kernel/locking/lockdep.c:3908
       __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5237
       lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
       console_lock_spinning_enable kernel/printk/printk.c:1924 [inline]
       console_emit_next_record kernel/printk/printk.c:3132 [inline]
       console_flush_all+0x6d2/0xc40 kernel/printk/printk.c:3226
       __console_flush_and_unlock kernel/printk/printk.c:3285 [inline]
       console_unlock+0xc4/0x270 kernel/printk/printk.c:3325
       vprintk_emit+0x5b7/0x7a0 kernel/printk/printk.c:2450
       _printk+0xcf/0x120 kernel/printk/printk.c:2475
       fail_dump lib/fault-inject.c:66 [inline]
       should_fail_ex+0x3f5/0x560 lib/fault-inject.c:174
       strncpy_from_user+0x36/0x290 lib/strncpy_from_user.c:118
       strncpy_from_user_nofault+0x72/0x150 mm/maccess.c:192
       bpf_probe_read_user_str_common kernel/trace/bpf_trace.c:215 [inline]
       ____bpf_probe_read_compat_str kernel/trace/bpf_trace.c:310 [inline]
       bpf_probe_read_compat_str+0xe2/0x180 kernel/trace/bpf_trace.c:306
       bpf_prog_c1796171ffc7efef+0x3e/0x44
       bpf_dispatcher_nop_func include/linux/bpf.h:1332 [inline]
       __bpf_prog_run include/linux/filter.h:718 [inline]
       bpf_prog_run include/linux/filter.h:725 [inline]
       __bpf_trace_run kernel/trace/bpf_trace.c:2257 [inline]
       bpf_trace_run4+0x28e/0x4a0 kernel/trace/bpf_trace.c:2300
       __bpf_trace_sched_switch+0x17a/0x1e0 include/trace/events/sched.h:220
       __traceiter_sched_switch+0x9d/0xd0 include/trace/events/sched.h:220
       __do_trace_sched_switch include/trace/events/sched.h:220 [inline]
       trace_sched_switch include/trace/events/sched.h:220 [inline]
       __schedule+0x238f/0x4cc0 kernel/sched/core.c:6958
       preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7288
       irqentry_exit+0x6f/0x90 kernel/entry/common.c:197
       asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:707
       fsnotify_sb_info include/linux/fsnotify_backend.h:577 [inline]
       fsnotify_sb_has_priority_watchers include/linux/fsnotify.h:24 [inline]
       fsnotify_sb_has_watchers include/linux/fsnotify.h:36 [inline]
       fsnotify_parent include/linux/fsnotify.h:81 [inline]
       fsnotify_path include/linux/fsnotify.h:113 [inline]
       fsnotify_file include/linux/fsnotify.h:127 [inline]
       fsnotify_modify include/linux/fsnotify.h:433 [inline]
       vfs_write+0x6f3/0xb30 fs/read_write.c:690
       ksys_write+0x145/0x250 fs/read_write.c:738
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

other info that might help us debug this:

Chain exists of:
  console_owner --> &p->pi_lock --> &rq->__lock

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&rq->__lock);
                               lock(&p->pi_lock);
                               lock(&rq->__lock);
  lock(console_owner);

 *** DEADLOCK ***

6 locks held by syz.3.1305/11258:
 #0: ffff88805c5d00f8 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x247/0x320 fs/file.c:1232
 #1: ffff888079c98428 (sb_writers#3){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3107 [inline]
 #1: ffff888079c98428 (sb_writers#3){.+.+}-{0:0}, at: vfs_write+0x211/0xb30 fs/read_write.c:682
 #2: ffff8880b8639f98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:636
 #3: ffffffff8e139ee0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #3: ffffffff8e139ee0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
 #3: ffffffff8e139ee0 (rcu_read_lock){....}-{1:3}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2256 [inline]
 #3: ffffffff8e139ee0 (rcu_read_lock){....}-{1:3}, at: bpf_trace_run4+0x19c/0x4a0 kernel/trace/bpf_trace.c:2300
 #4: ffffffff8e12e180 (console_lock){+.+.}-{0:0}, at: _printk+0xcf/0x120 kernel/printk/printk.c:2475
 #5: ffffffff8e015a50 (console_srcu){....}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:336 [inline]
 #5: ffffffff8e015a50 (console_srcu){....}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:319 [inline]
 #5: ffffffff8e015a50 (console_srcu){....}-{0:0}, at: console_srcu_read_lock kernel/printk/printk.c:288 [inline]
 #5: ffffffff8e015a50 (console_srcu){....}-{0:0}, at: console_flush_all+0x13a/0xc40 kernel/printk/printk.c:3203

stack backtrace:
CPU: 0 UID: 0 PID: 11258 Comm: syz.3.1305 Not tainted 6.17.0-rc1-syzkaller-00116-gd7ee5bdce789 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 print_circular_bug+0x2ee/0x310 kernel/locking/lockdep.c:2043
 check_noncircular+0x134/0x160 kernel/locking/lockdep.c:2175
 check_prev_add kernel/locking/lockdep.c:3165 [inline]
 check_prevs_add kernel/locking/lockdep.c:3284 [inline]
 validate_chain+0xb9b/0x2140 kernel/locking/lockdep.c:3908
 __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5237
 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
 console_lock_spinning_enable kernel/printk/printk.c:1924 [inline]
 console_emit_next_record kernel/printk/printk.c:3132 [inline]
 console_flush_all+0x6d2/0xc40 kernel/printk/printk.c:3226
 __console_flush_and_unlock kernel/printk/printk.c:3285 [inline]
 console_unlock+0xc4/0x270 kernel/printk/printk.c:3325
 vprintk_emit+0x5b7/0x7a0 kernel/printk/printk.c:2450
 _printk+0xcf/0x120 kernel/printk/printk.c:2475
 fail_dump lib/fault-inject.c:66 [inline]
 should_fail_ex+0x3f5/0x560 lib/fault-inject.c:174
 strncpy_from_user+0x36/0x290 lib/strncpy_from_user.c:118
 strncpy_from_user_nofault+0x72/0x150 mm/maccess.c:192
 bpf_probe_read_user_str_common kernel/trace/bpf_trace.c:215 [inline]
 ____bpf_probe_read_compat_str kernel/trace/bpf_trace.c:310 [inline]
 bpf_probe_read_compat_str+0xe2/0x180 kernel/trace/bpf_trace.c:306
 bpf_prog_c1796171ffc7efef+0x3e/0x44
 bpf_dispatcher_nop_func include/linux/bpf.h:1332 [inline]
 __bpf_prog_run include/linux/filter.h:718 [inline]
 bpf_prog_run include/linux/filter.h:725 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:2257 [inline]
 bpf_trace_run4+0x28e/0x4a0 kernel/trace/bpf_trace.c:2300
 __bpf_trace_sched_switch+0x17a/0x1e0 include/trace/events/sched.h:220
 __traceiter_sched_switch+0x9d/0xd0 include/trace/events/sched.h:220
 __do_trace_sched_switch include/trace/events/sched.h:220 [inline]
 trace_sched_switch include/trace/events/sched.h:220 [inline]
 __schedule+0x238f/0x4cc0 kernel/sched/core.c:6958
 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7288
 irqentry_exit+0x6f/0x90 kernel/entry/common.c:197
 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:707
RIP: 0010:fsnotify_sb_info include/linux/fsnotify_backend.h:577 [inline]
RIP: 0010:fsnotify_sb_has_priority_watchers include/linux/fsnotify.h:24 [inline]
RIP: 0010:fsnotify_sb_has_watchers include/linux/fsnotify.h:36 [inline]
RIP: 0010:fsnotify_parent include/linux/fsnotify.h:81 [inline]
RIP: 0010:fsnotify_path include/linux/fsnotify.h:113 [inline]
RIP: 0010:fsnotify_file include/linux/fsnotify.h:127 [inline]
RIP: 0010:fsnotify_modify include/linux/fsnotify.h:433 [inline]
RIP: 0010:vfs_write+0x6f3/0xb30 fs/read_write.c:690
Code: 8b 0b 48 89 4c 24 10 48 8d 59 28 48 89 d8 48 c1 e8 03 42 80 3c 20 00 74 08 48 89 df e8 96 84 ef ff 41 bc 68 06 00 00 4c 03 23 <4c> 89 e0 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 80 3c 08 00 74
RSP: 0018:ffffc90003c1fca0 EFLAGS: 00000282
RAX: 1ffff1100a57920c RBX: ffff888052bc9060 RCX: ffff888052bc9038
RDX: ffff888020bc5a00 RSI: 0000000004000000 RDI: 0000000002000000
RBP: ffffc90003c1fe10 R08: ffff888020bc5a2b R09: 1ffff11004178b45
R10: dffffc0000000000 R11: ffffed1004178b46 R12: ffff888079c98668
R13: ffff888058419be8 R14: 0000000000000001 R15: 1ffff92000783fa0
 ksys_write+0x145/0x250 fs/read_write.c:738
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb84038d69f
Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 f9 92 02 00 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 4c 93 02 00 48
RSP: 002b:00007fb841248030 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 000000000000000c RCX: 00007fb84038d69f
RDX: 0000000000000001 RSI: 00007fb841248090 RDI: 000000000000000c
RBP: 00007fb841248090 R08: 0000000000000000 R09: 00007fb841247df7
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000001
R13: 00007fb8405b6218 R14: 00007fb8405b6180 R15: 00007ffc61b7c218
 </TASK>
CPU: 0 UID: 0 PID: 11258 Comm: syz.3.1305 Not tainted 6.17.0-rc1-syzkaller-00116-gd7ee5bdce789 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 fail_dump lib/fault-inject.c:73 [inline]
 should_fail_ex+0x414/0x560 lib/fault-inject.c:174
 strncpy_from_user+0x36/0x290 lib/strncpy_from_user.c:118
 strncpy_from_user_nofault+0x72/0x150 mm/maccess.c:192
 bpf_probe_read_user_str_common kernel/trace/bpf_trace.c:215 [inline]
 ____bpf_probe_read_compat_str kernel/trace/bpf_trace.c:310 [inline]
 bpf_probe_read_compat_str+0xe2/0x180 kernel/trace/bpf_trace.c:306
 bpf_prog_c1796171ffc7efef+0x3e/0x44
 bpf_dispatcher_nop_func include/linux/bpf.h:1332 [inline]
 __bpf_prog_run include/linux/filter.h:718 [inline]
 bpf_prog_run include/linux/filter.h:725 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:2257 [inline]
 bpf_trace_run4+0x28e/0x4a0 kernel/trace/bpf_trace.c:2300
 __bpf_trace_sched_switch+0x17a/0x1e0 include/trace/events/sched.h:220
 __traceiter_sched_switch+0x9d/0xd0 include/trace/events/sched.h:220
 __do_trace_sched_switch include/trace/events/sched.h:220 [inline]
 trace_sched_switch include/trace/events/sched.h:220 [inline]
 __schedule+0x238f/0x4cc0 kernel/sched/core.c:6958
 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7288
 irqentry_exit+0x6f/0x90 kernel/entry/common.c:197
 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:707
RIP: 0010:fsnotify_sb_info include/linux/fsnotify_backend.h:577 [inline]
RIP: 0010:fsnotify_sb_has_priority_watchers include/linux/fsnotify.h:24 [inline]
RIP: 0010:fsnotify_sb_has_watchers include/linux/fsnotify.h:36 [inline]
RIP: 0010:fsnotify_parent include/linux/fsnotify.h:81 [inline]
RIP: 0010:fsnotify_path include/linux/fsnotify.h:113 [inline]
RIP: 0010:fsnotify_file include/linux/fsnotify.h:127 [inline]
RIP: 0010:fsnotify_modify include/linux/fsnotify.h:433 [inline]
RIP: 0010:vfs_write+0x6f3/0xb30 fs/read_write.c:690
Code: 8b 0b 48 89 4c 24 10 48 8d 59 28 48 89 d8 48 c1 e8 03 42 80 3c 20 00 74 08 48 89 df e8 96 84 ef ff 41 bc 68 06 00 00 4c 03 23 <4c> 89 e0 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 80 3c 08 00 74
RSP: 0018:ffffc90003c1fca0 EFLAGS: 00000282
RAX: 1ffff1100a57920c RBX: ffff888052bc9060 RCX: ffff888052bc9038
RDX: ffff888020bc5a00 RSI: 0000000004000000 RDI: 0000000002000000
RBP: ffffc90003c1fe10 R08: ffff888020bc5a2b R09: 1ffff11004178b45
R10: dffffc0000000000 R11: ffffed1004178b46 R12: ffff888079c98668
R13: ffff888058419be8 R14: 0000000000000001 R15: 1ffff92000783fa0
 ksys_write+0x145/0x250 fs/read_write.c:738
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb84038d69f
Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 f9 92 02 00 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 4c 93 02 00 48
RSP: 002b:00007fb841248030 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 000000000000000c RCX: 00007fb84038d69f
RDX: 0000000000000001 RSI: 00007fb841248090 RDI: 000000000000000c
RBP: 00007fb841248090 R08: 0000000000000000 R09: 00007fb841247df7
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000001
R13: 00007fb8405b6218 R14: 00007fb8405b6180 R15: 00007ffc61b7c218
 </TASK>
----------------
Code disassembly (best guess):
   0:	8b 0b                	mov    (%rbx),%ecx
   2:	48 89 4c 24 10       	mov    %rcx,0x10(%rsp)
   7:	48 8d 59 28          	lea    0x28(%rcx),%rbx
   b:	48 89 d8             	mov    %rbx,%rax
   e:	48 c1 e8 03          	shr    $0x3,%rax
  12:	42 80 3c 20 00       	cmpb   $0x0,(%rax,%r12,1)
  17:	74 08                	je     0x21
  19:	48 89 df             	mov    %rbx,%rdi
  1c:	e8 96 84 ef ff       	call   0xffef84b7
  21:	41 bc 68 06 00 00    	mov    $0x668,%r12d
  27:	4c 03 23             	add    (%rbx),%r12
* 2a:	4c 89 e0             	mov    %r12,%rax <-- trapping instruction
  2d:	48 c1 e8 03          	shr    $0x3,%rax
  31:	48 b9 00 00 00 00 00 	movabs $0xdffffc0000000000,%rcx
  38:	fc ff df
  3b:	80 3c 08 00          	cmpb   $0x0,(%rax,%rcx,1)
  3f:	74                   	.byte 0x74