FAULT_INJECTION: forcing a failure.
name fail_usercopy, interval 1, probability 0, space 0, times 0
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.1.955/6806 is trying to acquire lock:
ffffffff8c3139a0 (console_owner){-.-.}-{0:0}, at: console_lock_spinning_enable+0x2c/0x60 kernel/printk/printk.c:1802

but task is already holding lock:
ffff8880b903a358 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x25/0x130 kernel/sched/core.c:475

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #4 (&rq->__lock){-.-.}-{2:2}:
       _raw_spin_lock_nested+0x2e/0x40 kernel/locking/spinlock.c:368
       raw_spin_rq_lock_nested+0x25/0x130 kernel/sched/core.c:475
       raw_spin_rq_lock kernel/sched/sched.h:1326 [inline]
       rq_lock kernel/sched/sched.h:1621 [inline]
       task_fork_fair+0x5c/0x360 kernel/sched/fair.c:11499
       sched_cgroup_fork+0x2e8/0x340 kernel/sched/core.c:4485
       copy_process+0x2348/0x3ec0 kernel/fork.c:2397
       kernel_clone+0x23f/0x990 kernel/fork.c:2681
       kernel_thread+0xfa/0x160 kernel/fork.c:2733
       rest_init+0x21/0x330 init/main.c:720
       start_kernel+0x489/0x540 init/main.c:1153
       secondary_startup_64_no_verify+0xb1/0xbb

-> #3 (&p->pi_lock){-.-.}-{2:2}:
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0xb0/0x100 kernel/locking/spinlock.c:162
       try_to_wake_up+0x5a/0x1020 kernel/sched/core.c:4049
       __wake_up_common+0x28e/0x4d0 kernel/sched/wait.c:108
       __wake_up_common_lock kernel/sched/wait.c:138 [inline]
       __wake_up+0x10e/0x180 kernel/sched/wait.c:157
       tty_port_default_wakeup+0xa5/0xf0 drivers/tty/tty_port.c:51
       serial8250_tx_chars+0x615/0x800 drivers/tty/serial/8250/8250_port.c:1828
       serial8250_handle_irq+0x4f5/0x5f0 drivers/tty/serial/8250/8250_port.c:1924
       serial8250_default_handle_irq+0xb4/0x1a0 drivers/tty/serial/8250/8250_port.c:1941
       serial8250_interrupt+0x9b/0x1c0 drivers/tty/serial/8250/8250_core.c:127
       __handle_irq_event_percpu+0x299/0x9d0 kernel/irq/handle.c:156
       handle_irq_event_percpu kernel/irq/handle.c:196 [inline]
       handle_irq_event+0xa5/0x220 kernel/irq/handle.c:213
       handle_edge_irq+0x242/0xb20 kernel/irq/chip.c:819
       generic_handle_irq_desc include/linux/irqdesc.h:158 [inline]
       handle_irq arch/x86/kernel/irq.c:233 [inline]
       __common_interrupt+0xd7/0x1e0 arch/x86/kernel/irq.c:252
       common_interrupt+0xb0/0xd0 arch/x86/kernel/irq.c:242
       asm_common_interrupt+0x22/0x40 arch/x86/include/asm/idtentry.h:667
       stack_depot_save+0x157/0x460 lib/stackdepot.c:280
       kasan_save_stack mm/kasan/common.c:40 [inline]
       kasan_set_track+0x62/0x70 mm/kasan/common.c:46
       kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360
       ____kasan_slab_free+0xd5/0x110 mm/kasan/common.c:366
       kasan_slab_free include/linux/kasan.h:230 [inline]
       slab_free_hook mm/slub.c:1710 [inline]
       slab_free_freelist_hook+0xec/0x170 mm/slub.c:1736
       slab_free mm/slub.c:3504 [inline]
       kfree+0xef/0x2a0 mm/slub.c:4564
       tomoyo_realpath_from_path+0x5ad/0x5e0 security/tomoyo/realpath.c:291
       tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
       tomoyo_path_perm+0x23f/0x5d0 security/tomoyo/file.c:822
       security_inode_getattr+0xcf/0x120 security/security.c:1349
       vfs_getattr+0x26/0x3a0 fs/stat.c:157
       vfs_fstat fs/stat.c:182 [inline]
       __do_sys_newfstat fs/stat.c:421 [inline]
       __se_sys_newfstat fs/stat.c:418 [inline]
       __x64_sys_newfstat+0x137/0x210 fs/stat.c:418
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x66/0xd0

-> #2 (&tty->write_wait){-...}-{2:2}:
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0xb0/0x100 kernel/locking/spinlock.c:162
       __wake_up_common_lock kernel/sched/wait.c:137 [inline]
       __wake_up+0xf4/0x180 kernel/sched/wait.c:157
       tty_port_default_wakeup+0xa5/0xf0 drivers/tty/tty_port.c:51
       serial8250_tx_chars+0x615/0x800 drivers/tty/serial/8250/8250_port.c:1828
       serial8250_handle_irq+0x4f5/0x5f0 drivers/tty/serial/8250/8250_port.c:1924
       serial8250_default_handle_irq+0xb4/0x1a0 drivers/tty/serial/8250/8250_port.c:1941
       serial8250_interrupt+0x9b/0x1c0 drivers/tty/serial/8250/8250_core.c:127
       __handle_irq_event_percpu+0x299/0x9d0 kernel/irq/handle.c:156
       handle_irq_event_percpu kernel/irq/handle.c:196 [inline]
       handle_irq_event+0xa5/0x220 kernel/irq/handle.c:213
       handle_edge_irq+0x242/0xb20 kernel/irq/chip.c:819
       generic_handle_irq_desc include/linux/irqdesc.h:158 [inline]
       handle_irq arch/x86/kernel/irq.c:233 [inline]
       __common_interrupt+0xd7/0x1e0 arch/x86/kernel/irq.c:252
       common_interrupt+0xb0/0xd0 arch/x86/kernel/irq.c:242
       asm_common_interrupt+0x22/0x40 arch/x86/include/asm/idtentry.h:667
       native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline]
       arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline]
       default_idle+0xb/0x10 arch/x86/kernel/process.c:729
       default_idle_call+0x81/0xc0 kernel/sched/idle.c:112
       cpuidle_idle_call kernel/sched/idle.c:202 [inline]
       do_idle+0x251/0x650 kernel/sched/idle.c:326
       cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:424
       start_kernel+0x489/0x540 init/main.c:1153
       secondary_startup_64_no_verify+0xb1/0xbb

-> #1 (&port_lock_key){-.-.}-{2:2}:
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0xb0/0x100 kernel/locking/spinlock.c:162
       serial8250_console_write+0x16c/0xf50 drivers/tty/serial/8250/8250_port.c:3368
       call_console_drivers kernel/printk/printk.c:-1 [inline]
       console_unlock+0xb47/0x10f0 kernel/printk/printk.c:2744
       vprintk_emit+0xc0/0x150 kernel/printk/printk.c:2274
       _printk+0xda/0x130 kernel/printk/printk.c:2299
       register_console+0x693/0x970 kernel/printk/printk.c:3107
       univ8250_console_init+0x41/0x50 drivers/tty/serial/8250/8250_core.c:690
       console_init+0x177/0x5d0 kernel/printk/printk.c:3207
       start_kernel+0x2fc/0x540 init/main.c:1089
       secondary_startup_64_no_verify+0xb1/0xbb

-> #0 (console_owner){-.-.}-{0:0}:
       check_prev_add kernel/locking/lockdep.c:3053 [inline]
       check_prevs_add kernel/locking/lockdep.c:3172 [inline]
       validate_chain kernel/locking/lockdep.c:3788 [inline]
       __lock_acquire+0x2c66/0x7b50 kernel/locking/lockdep.c:5012
       lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623
       console_lock_spinning_enable+0x51/0x60 kernel/printk/printk.c:1805
       console_unlock+0x8b5/0x10f0 kernel/printk/printk.c:2741
       vprintk_emit+0xc0/0x150 kernel/printk/printk.c:2274
       _printk+0xda/0x130 kernel/printk/printk.c:2299
       fail_dump lib/fault-inject.c:45 [inline]
       should_fail+0x364/0x4b0 lib/fault-inject.c:146
       strncpy_from_user+0x32/0x350 lib/strncpy_from_user.c:118
       strncpy_from_user_nofault+0x6d/0x140 mm/maccess.c:295
       bpf_probe_read_user_str_common kernel/trace/bpf_trace.c:194 [inline]
       ____bpf_probe_read_user_str kernel/trace/bpf_trace.c:203 [inline]
       bpf_probe_read_user_str+0x26/0x70 kernel/trace/bpf_trace.c:200
       bpf_prog_cbd2ad7029fad3e7+0x3d/0xfe8
       bpf_dispatcher_nop_func include/linux/bpf.h:888 [inline]
       __bpf_prog_run include/linux/filter.h:628 [inline]
       bpf_prog_run include/linux/filter.h:635 [inline]
       BPF_PROG_RUN_ARRAY include/linux/bpf.h:1439 [inline]
       trace_call_bpf+0x2b1/0x5b0 kernel/trace/bpf_trace.c:127
       perf_trace_run_bpf_submit+0x79/0x1c0 kernel/events/core.c:10016
       perf_trace_lock_acquire+0x341/0x3f0 include/trace/events/lock.h:13
       trace_lock_acquire include/trace/events/lock.h:13 [inline]
       lock_acquire+0x3d7/0x400 kernel/locking/lockdep.c:5594
       __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
       _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154
       perf_event_context_sched_out kernel/events/core.c:3620 [inline]
       __perf_event_task_sched_out+0x6ba/0xec0 kernel/events/core.c:3729
       perf_event_task_sched_out include/linux/perf_event.h:1253 [inline]
       prepare_task_switch kernel/sched/core.c:4853 [inline]
       context_switch kernel/sched/core.c:5001 [inline]
       __schedule+0x20ec/0x4350 kernel/sched/core.c:6395
       preempt_schedule_notrace+0xd9/0x120 kernel/sched/core.c:6650
       preempt_schedule_notrace_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:35
       trace_lock_acquire include/trace/events/lock.h:13 [inline]
       lock_acquire+0x3ed/0x400 kernel/locking/lockdep.c:5594
       rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:313
       rcu_read_lock include/linux/rcupdate.h:740 [inline]
       __fget_files+0x2f/0x470 fs/file.c:902
       __fget fs/file.c:912 [inline]
       __fget_light fs/file.c:1016 [inline]
       __fdget+0x17e/0x210 fs/file.c:1024
       fdget include/linux/file.h:66 [inline]
       __do_sys_ioctl fs/ioctl.c:862 [inline]
       __se_sys_ioctl+0x20/0x170 fs/ioctl.c:860
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x66/0xd0

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 ***

3 locks held by syz.1.955/6806:
 #0: ffff8880b903a358 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x25/0x130 kernel/sched/core.c:475
 #1: ffffffff8c31ef20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:312
 #2: ffffffff8c313a80 (console_lock){+.+.}-{0:0}, at: vprintk_emit+0xa7/0x150 kernel/printk/printk.c:2273

stack backtrace:
CPU: 0 PID: 6806 Comm: syz.1.955 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
 check_noncircular+0x296/0x330 kernel/locking/lockdep.c:2133
 check_prev_add kernel/locking/lockdep.c:3053 [inline]
 check_prevs_add kernel/locking/lockdep.c:3172 [inline]
 validate_chain kernel/locking/lockdep.c:3788 [inline]
 __lock_acquire+0x2c66/0x7b50 kernel/locking/lockdep.c:5012
 lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623
 console_lock_spinning_enable+0x51/0x60 kernel/printk/printk.c:1805
 console_unlock+0x8b5/0x10f0 kernel/printk/printk.c:2741
 vprintk_emit+0xc0/0x150 kernel/printk/printk.c:2274
 _printk+0xda/0x130 kernel/printk/printk.c:2299
 fail_dump lib/fault-inject.c:45 [inline]
 should_fail+0x364/0x4b0 lib/fault-inject.c:146
 strncpy_from_user+0x32/0x350 lib/strncpy_from_user.c:118
 strncpy_from_user_nofault+0x6d/0x140 mm/maccess.c:295
 bpf_probe_read_user_str_common kernel/trace/bpf_trace.c:194 [inline]
 ____bpf_probe_read_user_str kernel/trace/bpf_trace.c:203 [inline]
 bpf_probe_read_user_str+0x26/0x70 kernel/trace/bpf_trace.c:200
 bpf_prog_cbd2ad7029fad3e7+0x3d/0xfe8
 bpf_dispatcher_nop_func include/linux/bpf.h:888 [inline]
 __bpf_prog_run include/linux/filter.h:628 [inline]
 bpf_prog_run include/linux/filter.h:635 [inline]
 BPF_PROG_RUN_ARRAY include/linux/bpf.h:1439 [inline]
 trace_call_bpf+0x2b1/0x5b0 kernel/trace/bpf_trace.c:127
 perf_trace_run_bpf_submit+0x79/0x1c0 kernel/events/core.c:10016
 perf_trace_lock_acquire+0x341/0x3f0 include/trace/events/lock.h:13
 trace_lock_acquire include/trace/events/lock.h:13 [inline]
 lock_acquire+0x3d7/0x400 kernel/locking/lockdep.c:5594
 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
 _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154
 perf_event_context_sched_out kernel/events/core.c:3620 [inline]
 __perf_event_task_sched_out+0x6ba/0xec0 kernel/events/core.c:3729
 perf_event_task_sched_out include/linux/perf_event.h:1253 [inline]
 prepare_task_switch kernel/sched/core.c:4853 [inline]
 context_switch kernel/sched/core.c:5001 [inline]
 __schedule+0x20ec/0x4350 kernel/sched/core.c:6395
 preempt_schedule_notrace+0xd9/0x120 kernel/sched/core.c:6650
 preempt_schedule_notrace_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:35
 trace_lock_acquire include/trace/events/lock.h:13 [inline]
 lock_acquire+0x3ed/0x400 kernel/locking/lockdep.c:5594
 rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:313
 rcu_read_lock include/linux/rcupdate.h:740 [inline]
 __fget_files+0x2f/0x470 fs/file.c:902
 __fget fs/file.c:912 [inline]
 __fget_light fs/file.c:1016 [inline]
 __fdget+0x17e/0x210 fs/file.c:1024
 fdget include/linux/file.h:66 [inline]
 __do_sys_ioctl fs/ioctl.c:862 [inline]
 __se_sys_ioctl+0x20/0x170 fs/ioctl.c:860
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fbbcee23e59
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fbbcd07d028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fbbcf09cfa0 RCX: 00007fbbcee23e59
RDX: 0000200000000080 RSI: 00000000000089f1 RDI: 0000000000000007
RBP: 00007fbbcd07d090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007fbbcf09d038 R14: 00007fbbcf09cfa0 R15: 00007ffea2acece8
 </TASK>
CPU: 0 PID: 6806 Comm: syz.1.955 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
 fail_dump lib/fault-inject.c:52 [inline]
 should_fail+0x383/0x4b0 lib/fault-inject.c:146
 strncpy_from_user+0x32/0x350 lib/strncpy_from_user.c:118
 strncpy_from_user_nofault+0x6d/0x140 mm/maccess.c:295
 bpf_probe_read_user_str_common kernel/trace/bpf_trace.c:194 [inline]
 ____bpf_probe_read_user_str kernel/trace/bpf_trace.c:203 [inline]
 bpf_probe_read_user_str+0x26/0x70 kernel/trace/bpf_trace.c:200
 bpf_prog_cbd2ad7029fad3e7+0x3d/0xfe8
 bpf_dispatcher_nop_func include/linux/bpf.h:888 [inline]
 __bpf_prog_run include/linux/filter.h:628 [inline]
 bpf_prog_run include/linux/filter.h:635 [inline]
 BPF_PROG_RUN_ARRAY include/linux/bpf.h:1439 [inline]
 trace_call_bpf+0x2b1/0x5b0 kernel/trace/bpf_trace.c:127
 perf_trace_run_bpf_submit+0x79/0x1c0 kernel/events/core.c:10016
 perf_trace_lock_acquire+0x341/0x3f0 include/trace/events/lock.h:13
 trace_lock_acquire include/trace/events/lock.h:13 [inline]
 lock_acquire+0x3d7/0x400 kernel/locking/lockdep.c:5594
 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
 _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154
 perf_event_context_sched_out kernel/events/core.c:3620 [inline]
 __perf_event_task_sched_out+0x6ba/0xec0 kernel/events/core.c:3729
 perf_event_task_sched_out include/linux/perf_event.h:1253 [inline]
 prepare_task_switch kernel/sched/core.c:4853 [inline]
 context_switch kernel/sched/core.c:5001 [inline]
 __schedule+0x20ec/0x4350 kernel/sched/core.c:6395
 preempt_schedule_notrace+0xd9/0x120 kernel/sched/core.c:6650
 preempt_schedule_notrace_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:35
 trace_lock_acquire include/trace/events/lock.h:13 [inline]
 lock_acquire+0x3ed/0x400 kernel/locking/lockdep.c:5594
 rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:313
 rcu_read_lock include/linux/rcupdate.h:740 [inline]
 __fget_files+0x2f/0x470 fs/file.c:902
 __fget fs/file.c:912 [inline]
 __fget_light fs/file.c:1016 [inline]
 __fdget+0x17e/0x210 fs/file.c:1024
 fdget include/linux/file.h:66 [inline]
 __do_sys_ioctl fs/ioctl.c:862 [inline]
 __se_sys_ioctl+0x20/0x170 fs/ioctl.c:860
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fbbcee23e59
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fbbcd07d028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fbbcf09cfa0 RCX: 00007fbbcee23e59
RDX: 0000200000000080 RSI: 00000000000089f1 RDI: 0000000000000007
RBP: 00007fbbcd07d090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007fbbcf09d038 R14: 00007fbbcf09cfa0 R15: 00007ffea2acece8
 </TASK>