syzbot

FAULT_INJECTION: forcing a failure.
name fail_usercopy, interval 1, probability 0, space 0, times 1
======================================================
WARNING: possible circular locking dependency detected
6.14.0-rc3-syzkaller-00060-g6537cfb395f3 #0 Not tainted
------------------------------------------------------
syz-executor316/5849 is trying to acquire lock:
ffffffff8ea14ac0 (console_owner){-...}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:342 [inline]
ffffffff8ea14ac0 (console_owner){-...}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:304 [inline]
ffffffff8ea14ac0 (console_owner){-...}-{0:0}, at: console_srcu_read_lock kernel/printk/printk.c:288 [inline]
ffffffff8ea14ac0 (console_owner){-...}-{0:0}, at: console_flush_all+0x1a3/0xeb0 kernel/printk/printk.c:3187

but task is already holding lock:
ffff8880b873e7d8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:598

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #4 (&rq->__lock){-.-.}-{2:2}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851
       _raw_spin_lock_nested+0x31/0x40 kernel/locking/spinlock.c:378
       raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:598
       raw_spin_rq_lock kernel/sched/sched.h:1521 [inline]
       task_rq_lock+0xc6/0x360 kernel/sched/core.c:700
       cgroup_move_task+0x9b/0x5a0 kernel/sched/psi.c:1161
       css_set_move_task+0x72e/0x950 kernel/cgroup/cgroup.c:898
       cgroup_post_fork+0x284/0x8b0 kernel/cgroup/cgroup.c:6695
       copy_process+0x398a/0x3cf0 kernel/fork.c:2629
       kernel_clone+0x223/0x870 kernel/fork.c:2815
       user_mode_thread+0x144/0x1c0 kernel/fork.c:2893
       rest_init+0x23/0x300 init/main.c:708
       start_kernel+0x484/0x510 init/main.c:1099
       x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:515
       x86_64_start_kernel+0x66/0x70 arch/x86/kernel/head64.c:496
       common_startup_64+0x13e/0x147

-> #3 (&p->pi_lock){-.-.}-{2:2}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162
       class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:551 [inline]
       try_to_wake_up+0xc2/0x1470 kernel/sched/core.c:4214
       __wake_up_common kernel/sched/wait.c:89 [inline]
       __wake_up_common_lock+0x130/0x1e0 kernel/sched/wait.c:106
       tty_port_default_wakeup+0xa6/0xf0 drivers/tty/tty_port.c:69
       serial8250_tx_chars+0x6e2/0x930 drivers/tty/serial/8250/8250_port.c:1844
       serial8250_handle_irq+0x631/0xb80 drivers/tty/serial/8250/8250_port.c:1952
       serial8250_default_handle_irq+0xd1/0x1f0 drivers/tty/serial/8250/8250_port.c:1972
       serial8250_interrupt+0xa9/0x1f0 drivers/tty/serial/8250/8250_core.c:86
       __handle_irq_event_percpu+0x29a/0xa60 kernel/irq/handle.c:158
       handle_irq_event_percpu kernel/irq/handle.c:193 [inline]
       handle_irq_event+0x89/0x1f0 kernel/irq/handle.c:210
       handle_edge_irq+0x25f/0xc20 kernel/irq/chip.c:831
       generic_handle_irq_desc include/linux/irqdesc.h:173 [inline]
       handle_irq arch/x86/kernel/irq.c:247 [inline]
       call_irq_handler arch/x86/kernel/irq.c:259 [inline]
       __common_interrupt+0x136/0x230 arch/x86/kernel/irq.c:285
       common_interrupt+0xb4/0xd0 arch/x86/kernel/irq.c:278
       asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:693
       native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline]
       arch_safe_halt arch/x86/include/asm/irqflags.h:106 [inline]
       acpi_safe_halt+0x21/0x30 drivers/acpi/processor_idle.c:111
       acpi_idle_enter+0xe4/0x140 drivers/acpi/processor_idle.c:699
       cpuidle_enter_state+0x109/0x470 drivers/cpuidle/cpuidle.c:268
       cpuidle_enter+0x5d/0xa0 drivers/cpuidle/cpuidle.c:389
       call_cpuidle kernel/sched/idle.c:155 [inline]
       cpuidle_idle_call kernel/sched/idle.c:230 [inline]
       do_idle+0x372/0x5c0 kernel/sched/idle.c:325
       cpu_startup_entry+0x42/0x60 kernel/sched/idle.c:423
       rest_init+0x2dc/0x300 init/main.c:743
       start_kernel+0x484/0x510 init/main.c:1099
       x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:515
       x86_64_start_kernel+0x66/0x70 arch/x86/kernel/head64.c:496
       common_startup_64+0x13e/0x147

-> #2 (&tty->write_wait){-.-.}-{3:3}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162
       __wake_up_common_lock+0x25/0x1e0 kernel/sched/wait.c:105
       tty_port_default_wakeup+0xa6/0xf0 drivers/tty/tty_port.c:69
       serial8250_tx_chars+0x6e2/0x930 drivers/tty/serial/8250/8250_port.c:1844
       serial8250_handle_irq+0x631/0xb80 drivers/tty/serial/8250/8250_port.c:1952
       serial8250_default_handle_irq+0xd1/0x1f0 drivers/tty/serial/8250/8250_port.c:1972
       serial8250_interrupt+0xa9/0x1f0 drivers/tty/serial/8250/8250_core.c:86
       __handle_irq_event_percpu+0x29a/0xa60 kernel/irq/handle.c:158
       handle_irq_event_percpu kernel/irq/handle.c:193 [inline]
       handle_irq_event+0x89/0x1f0 kernel/irq/handle.c:210
       handle_edge_irq+0x25f/0xc20 kernel/irq/chip.c:831
       generic_handle_irq_desc include/linux/irqdesc.h:173 [inline]
       handle_irq arch/x86/kernel/irq.c:247 [inline]
       call_irq_handler arch/x86/kernel/irq.c:259 [inline]
       __common_interrupt+0x136/0x230 arch/x86/kernel/irq.c:285
       common_interrupt+0xb4/0xd0 arch/x86/kernel/irq.c:278
       asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:693
       __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
       _raw_spin_unlock_irqrestore+0xd8/0x140 kernel/locking/spinlock.c:194
       spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]
       uart_port_unlock_irqrestore include/linux/serial_core.h:786 [inline]
       uart_write+0x3e4/0xa40 drivers/tty/serial/serial_core.c:636
       process_output_block drivers/tty/n_tty.c:574 [inline]
       n_tty_write+0xd62/0x1230 drivers/tty/n_tty.c:2389
       iterate_tty_write drivers/tty/tty_io.c:1015 [inline]
       file_tty_write+0x546/0x9b0 drivers/tty/tty_io.c:1090
       new_sync_write fs/read_write.c:586 [inline]
       vfs_write+0xacf/0xd10 fs/read_write.c:679
       ksys_write+0x18f/0x2b0 fs/read_write.c:731
       do_syscall_x64 arch/x86/entry/common.c:52 [inline]
       do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #1 (&port_lock_key){-.-.}-{3:3}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162
       uart_port_lock_irqsave include/linux/serial_core.h:715 [inline]
       serial8250_console_write+0x1ae/0x1e00 drivers/tty/serial/8250/8250_port.c:3424
       console_emit_next_record kernel/printk/printk.c:3122 [inline]
       console_flush_all+0x86b/0xeb0 kernel/printk/printk.c:3210
       __console_flush_and_unlock kernel/printk/printk.c:3269 [inline]
       console_unlock+0x14f/0x3b0 kernel/printk/printk.c:3309
       vprintk_emit+0x730/0xa10 kernel/printk/printk.c:2432
       _printk+0xd5/0x120 kernel/printk/printk.c:2457
       register_console+0xbf5/0xfd0 kernel/printk/printk.c:4099
       univ8250_console_init+0x52/0x90 drivers/tty/serial/8250/8250_core.c:513
       console_init+0x1b8/0x6f0 kernel/printk/printk.c:4292
       start_kernel+0x2dd/0x510 init/main.c:1034
       x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:515
       x86_64_start_kernel+0x66/0x70 arch/x86/kernel/head64.c:496
       common_startup_64+0x13e/0x147

-> #0 (console_owner){-...}-{0:0}:
       check_prev_add kernel/locking/lockdep.c:3163 [inline]
       check_prevs_add kernel/locking/lockdep.c:3282 [inline]
       validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3906
       __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5228
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851
       console_lock_spinning_enable kernel/printk/printk.c:1924 [inline]
       console_emit_next_record kernel/printk/printk.c:3116 [inline]
       console_flush_all+0x7f8/0xeb0 kernel/printk/printk.c:3210
       __console_flush_and_unlock kernel/printk/printk.c:3269 [inline]
       console_unlock+0x14f/0x3b0 kernel/printk/printk.c:3309
       vprintk_emit+0x730/0xa10 kernel/printk/printk.c:2432
       _printk+0xd5/0x120 kernel/printk/printk.c:2457
       fail_dump lib/fault-inject.c:66 [inline]
       should_fail_ex+0x3eb/0x550 lib/fault-inject.c:174
       strncpy_from_user+0x36/0x270 lib/strncpy_from_user.c:118
       strncpy_from_user_nofault+0x71/0x140 mm/maccess.c:193
       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+0xe9/0x180 kernel/trace/bpf_trace.c:306
       bpf_prog_c1796171ffc7efef+0x3e/0x40
       bpf_dispatcher_nop_func include/linux/bpf.h:1290 [inline]
       __bpf_prog_run include/linux/filter.h:701 [inline]
       bpf_prog_run include/linux/filter.h:708 [inline]
       __bpf_trace_run kernel/trace/bpf_trace.c:2371 [inline]
       bpf_trace_run4+0x334/0x590 kernel/trace/bpf_trace.c:2414
       __bpf_trace_sched_switch+0x294/0x3d0 include/trace/events/sched.h:222
       __traceiter_sched_switch+0x98/0xd0 include/trace/events/sched.h:222
       __do_trace_sched_switch include/trace/events/sched.h:222 [inline]
       trace_sched_switch include/trace/events/sched.h:222 [inline]
       __schedule+0x235b/0x4c40 kernel/sched/core.c:6762
       __schedule_loop kernel/sched/core.c:6842 [inline]
       schedule+0x14b/0x320 kernel/sched/core.c:6857
       ptrace_stop+0x5b4/0x940 kernel/signal.c:2476
       ptrace_do_notify kernel/signal.c:2513 [inline]
       ptrace_notify+0x255/0x380 kernel/signal.c:2525
       ptrace_report_syscall include/linux/ptrace.h:415 [inline]
       ptrace_report_syscall_exit include/linux/ptrace.h:477 [inline]
       syscall_exit_work+0xc7/0x1d0 kernel/entry/common.c:173
       syscall_exit_to_user_mode_prepare kernel/entry/common.c:200 [inline]
       __syscall_exit_to_user_mode_work kernel/entry/common.c:205 [inline]
       syscall_exit_to_user_mode+0x24a/0x340 kernel/entry/common.c:218
       do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89
       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 ***

4 locks held by syz-executor316/5849:
 #0: ffff8880b873e7d8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:598
 #1: ffffffff8eb38f60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
 #1: ffffffff8eb38f60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #1: ffffffff8eb38f60 (rcu_read_lock){....}-{1:3}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2370 [inline]
 #1: ffffffff8eb38f60 (rcu_read_lock){....}-{1:3}, at: bpf_trace_run4+0x244/0x590 kernel/trace/bpf_trace.c:2414
 #2: ffffffff8ea14b20 (console_lock){+.+.}-{0:0}, at: _printk+0xd5/0x120 kernel/printk/printk.c:2457
 #3: ffffffff8ea14730 (console_srcu){....}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:342 [inline]
 #3: ffffffff8ea14730 (console_srcu){....}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:304 [inline]
 #3: ffffffff8ea14730 (console_srcu){....}-{0:0}, at: console_srcu_read_lock kernel/printk/printk.c:288 [inline]
 #3: ffffffff8ea14730 (console_srcu){....}-{0:0}, at: console_flush_all+0x1a3/0xeb0 kernel/printk/printk.c:3187

stack backtrace:
CPU: 1 UID: 0 PID: 5849 Comm: syz-executor316 Not tainted 6.14.0-rc3-syzkaller-00060-g6537cfb395f3 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 print_circular_bug+0x13a/0x1b0 kernel/locking/lockdep.c:2076
 check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2208
 check_prev_add kernel/locking/lockdep.c:3163 [inline]
 check_prevs_add kernel/locking/lockdep.c:3282 [inline]
 validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3906
 __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5228
 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851
 console_lock_spinning_enable kernel/printk/printk.c:1924 [inline]
 console_emit_next_record kernel/printk/printk.c:3116 [inline]
 console_flush_all+0x7f8/0xeb0 kernel/printk/printk.c:3210
 __console_flush_and_unlock kernel/printk/printk.c:3269 [inline]
 console_unlock+0x14f/0x3b0 kernel/printk/printk.c:3309
 vprintk_emit+0x730/0xa10 kernel/printk/printk.c:2432
 _printk+0xd5/0x120 kernel/printk/printk.c:2457
 fail_dump lib/fault-inject.c:66 [inline]
 should_fail_ex+0x3eb/0x550 lib/fault-inject.c:174
 strncpy_from_user+0x36/0x270 lib/strncpy_from_user.c:118
 strncpy_from_user_nofault+0x71/0x140 mm/maccess.c:193
 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+0xe9/0x180 kernel/trace/bpf_trace.c:306
 bpf_prog_c1796171ffc7efef+0x3e/0x40
 bpf_dispatcher_nop_func include/linux/bpf.h:1290 [inline]
 __bpf_prog_run include/linux/filter.h:701 [inline]
 bpf_prog_run include/linux/filter.h:708 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:2371 [inline]
 bpf_trace_run4+0x334/0x590 kernel/trace/bpf_trace.c:2414
 __bpf_trace_sched_switch+0x294/0x3d0 include/trace/events/sched.h:222
 __traceiter_sched_switch+0x98/0xd0 include/trace/events/sched.h:222
 __do_trace_sched_switch include/trace/events/sched.h:222 [inline]
 trace_sched_switch include/trace/events/sched.h:222 [inline]
 __schedule+0x235b/0x4c40 kernel/sched/core.c:6762
 __schedule_loop kernel/sched/core.c:6842 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6857
 ptrace_stop+0x5b4/0x940 kernel/signal.c:2476
 ptrace_do_notify kernel/signal.c:2513 [inline]
 ptrace_notify+0x255/0x380 kernel/signal.c:2525
 ptrace_report_syscall include/linux/ptrace.h:415 [inline]
 ptrace_report_syscall_exit include/linux/ptrace.h:477 [inline]
 syscall_exit_work+0xc7/0x1d0 kernel/entry/common.c:173
 syscall_exit_to_user_mode_prepare kernel/entry/common.c:200 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:205 [inline]
 syscall_exit_to_user_mode+0x24a/0x340 kernel/entry/common.c:218
 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f27dd62877f
Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 89 5e 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 dc 5e 02 00 48
RSP: 002b:00007f27dd5bb1d0 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: 0000000000000001 RBX: 00007f27dd6ac3f8 RCX: 00007f27dd62877f
RDX: 0000000000000001 RSI: 00007f27dd5bb210 RDI: 0000000000000005
RBP: 00007f27dd6ac3f0 R08: 0000000000000000 R09: 00007f27dd5baf97
R10: 0000000000000000 R11: 0000000000000293 R12: 00007f27dd5bb210
R13: 00007f27dd679284 R14: 0000000000000005 R15: 00004000000000c0
 </TASK>
CPU: 1 UID: 0 PID: 5849 Comm: syz-executor316 Not tainted 6.14.0-rc3-syzkaller-00060-g6537cfb395f3 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 fail_dump lib/fault-inject.c:73 [inline]
 should_fail_ex+0x40a/0x550 lib/fault-inject.c:174
 strncpy_from_user+0x36/0x270 lib/strncpy_from_user.c:118
 strncpy_from_user_nofault+0x71/0x140 mm/maccess.c:193
 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+0xe9/0x180 kernel/trace/bpf_trace.c:306
 bpf_prog_c1796171ffc7efef+0x3e/0x40
 bpf_dispatcher_nop_func include/linux/bpf.h:1290 [inline]
 __bpf_prog_run include/linux/filter.h:701 [inline]
 bpf_prog_run include/linux/filter.h:708 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:2371 [inline]
 bpf_trace_run4+0x334/0x590 kernel/trace/bpf_trace.c:2414
 __bpf_trace_sched_switch+0x294/0x3d0 include/trace/events/sched.h:222
 __traceiter_sched_switch+0x98/0xd0 include/trace/events/sched.h:222
 __do_trace_sched_switch include/trace/events/sched.h:222 [inline]
 trace_sched_switch include/trace/events/sched.h:222 [inline]
 __schedule+0x235b/0x4c40 kernel/sched/core.c:6762
 __schedule_loop kernel/sched/core.c:6842 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6857
 ptrace_stop+0x5b4/0x940 kernel/signal.c:2476
 ptrace_do_notify kernel/signal.c:2513 [inline]
 ptrace_notify+0x255/0x380 kernel/signal.c:2525
 ptrace_report_syscall include/linux/ptrace.h:415 [inline]
 ptrace_report_syscall_exit include/linux/ptrace.h:477 [inline]
 syscall_exit_work+0xc7/0x1d0 kernel/entry/common.c:173
 syscall_exit_to_user_mode_prepare kernel/entry/common.c:200 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:205 [inline]
 syscall_exit_to_user_mode+0x24a/0x340 kernel/entry/common.c:218
 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f27dd62877f
Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 89 5e 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 dc 5e 02 00 48
RSP: 002b:00007f27dd5bb1d0 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: 0000000000000001 RBX: 00007f27dd6ac3f8 RCX: 00007f27dd62877f
RDX: 0000000000000001 RSI: 00007f27dd5bb210 RDI: 0000000000000005
RBP: 00007f27dd6ac3f0 R08: 0000000000000000 R09: 00007f27dd5baf97
R10: 0000000000000000 R11: 0000000000000293 R12: 00007f27dd5bb210
R13: 00007f27dd679284 R14: 0000000000000005 R15: 00004000000000c0
 </TASK>