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.0.5085/21120 is trying to acquire lock:
ffffffff8d1260a0 (console_owner){-.-.}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:339 [inline]
ffffffff8d1260a0 (console_owner){-.-.}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:232 [inline]
ffffffff8d1260a0 (console_owner){-.-.}-{0:0}, at: console_srcu_read_lock kernel/printk/printk.c:292 [inline]
ffffffff8d1260a0 (console_owner){-.-.}-{0:0}, at: console_flush_all+0x10b/0xcf0 kernel/printk/printk.c:2992

but task is already holding lock:
ffff8880b8f3c298 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x29/0x130 kernel/sched/core.c:559

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+0x32/0x50 kernel/locking/spinlock.c:378
       raw_spin_rq_lock_nested+0x29/0x130 kernel/sched/core.c:559
       raw_spin_rq_lock kernel/sched/sched.h:1379 [inline]
       rq_lock kernel/sched/sched.h:1688 [inline]
       task_fork_fair+0x62/0x1f0 kernel/sched/fair.c:12728
       sched_cgroup_fork+0x352/0x3e0 kernel/sched/core.c:4818
       copy_process+0x21fd/0x3da0 kernel/fork.c:2619
       kernel_clone+0x24b/0x8a0 kernel/fork.c:2919
       user_mode_thread+0x111/0x180 kernel/fork.c:2997
       rest_init+0x27/0x300 init/main.c:670
       arch_call_rest_init+0xe/0x10 init/main.c:801
       start_kernel+0x461/0x4e0 init/main.c:1046
       x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:555
       copy_bootdata+0x0/0xd0 arch/x86/kernel/head64.c:536
       secondary_startup_64_no_verify+0x179/0x17b

-> #3 (&p->pi_lock){-.-.}-{2:2}:
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0xb4/0x100 kernel/locking/spinlock.c:162
       class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:523 [inline]
       try_to_wake_up+0x5b/0x10e0 kernel/sched/core.c:4233
       __wake_up_common+0x28e/0x4d0 kernel/sched/wait.c:107
       __wake_up_common_lock kernel/sched/wait.c:138 [inline]
       __wake_up+0x125/0x1a0 kernel/sched/wait.c:160
       tty_port_default_wakeup+0xa2/0xf0 drivers/tty/tty_port.c:69
       serial8250_tx_chars+0x6a2/0x8b0 drivers/tty/serial/8250/8250_port.c:1837
       serial8250_handle_irq+0x567/0x730 drivers/tty/serial/8250/8250_port.c:1944
       serial8250_default_handle_irq+0xb8/0x1a0 drivers/tty/serial/8250/8250_port.c:1964
       serial8250_interrupt+0x9f/0x1c0 drivers/tty/serial/8250/8250_core.c:127
       __handle_irq_event_percpu+0x271/0x940 kernel/irq/handle.c:158
       handle_irq_event_percpu kernel/irq/handle.c:193 [inline]
       handle_irq_event+0x8b/0x1e0 kernel/irq/handle.c:210
       handle_edge_irq+0x246/0xb20 kernel/irq/chip.c:831
       generic_handle_irq_desc include/linux/irqdesc.h:161 [inline]
       handle_irq arch/x86/kernel/irq.c:240 [inline]
       __common_interrupt+0x13b/0x230 arch/x86/kernel/irq.c:259
       common_interrupt+0xb4/0xd0 arch/x86/kernel/irq.c:249
       asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:678
       native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline]
       pv_native_safe_halt+0xf/0x10 arch/x86/kernel/paravirt.c:147
       arch_safe_halt arch/x86/include/asm/paravirt.h:108 [inline]
       default_idle+0x13/0x20 arch/x86/kernel/process.c:753
       default_idle_call+0x6c/0xa0 kernel/sched/idle.c:97
       cpuidle_idle_call kernel/sched/idle.c:178 [inline]
       do_idle+0x221/0x5c0 kernel/sched/idle.c:302
       cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:401
       rest_init+0x2e2/0x300 init/main.c:705
       arch_call_rest_init+0xe/0x10 init/main.c:801
       start_kernel+0x461/0x4e0 init/main.c:1046
       x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:555
       copy_bootdata+0x0/0xd0 arch/x86/kernel/head64.c:536
       secondary_startup_64_no_verify+0x179/0x17b

-> #2 (&tty->write_wait){-.-.}-{2:2}:
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0xb4/0x100 kernel/locking/spinlock.c:162
       __wake_up_common_lock kernel/sched/wait.c:137 [inline]
       __wake_up+0x10b/0x1a0 kernel/sched/wait.c:160
       tty_port_default_wakeup+0xa2/0xf0 drivers/tty/tty_port.c:69
       serial8250_tx_chars+0x6a2/0x8b0 drivers/tty/serial/8250/8250_port.c:1837
       serial8250_handle_irq+0x567/0x730 drivers/tty/serial/8250/8250_port.c:1944
       serial8250_default_handle_irq+0xb8/0x1a0 drivers/tty/serial/8250/8250_port.c:1964
       serial8250_interrupt+0x9f/0x1c0 drivers/tty/serial/8250/8250_core.c:127
       __handle_irq_event_percpu+0x271/0x940 kernel/irq/handle.c:158
       handle_irq_event_percpu kernel/irq/handle.c:193 [inline]
       handle_irq_event+0x8b/0x1e0 kernel/irq/handle.c:210
       handle_edge_irq+0x246/0xb20 kernel/irq/chip.c:831
       generic_handle_irq_desc include/linux/irqdesc.h:161 [inline]
       handle_irq arch/x86/kernel/irq.c:240 [inline]
       __common_interrupt+0x13b/0x230 arch/x86/kernel/irq.c:259
       common_interrupt+0xb4/0xd0 arch/x86/kernel/irq.c:249
       asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:678
       native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline]
       pv_native_safe_halt+0xf/0x10 arch/x86/kernel/paravirt.c:147
       arch_safe_halt arch/x86/include/asm/paravirt.h:108 [inline]
       default_idle+0x13/0x20 arch/x86/kernel/process.c:753
       default_idle_call+0x6c/0xa0 kernel/sched/idle.c:97
       cpuidle_idle_call kernel/sched/idle.c:178 [inline]
       do_idle+0x221/0x5c0 kernel/sched/idle.c:302
       cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:401
       rest_init+0x2e2/0x300 init/main.c:705
       arch_call_rest_init+0xe/0x10 init/main.c:801
       start_kernel+0x461/0x4e0 init/main.c:1046
       x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:555
       copy_bootdata+0x0/0xd0 arch/x86/kernel/head64.c:536
       secondary_startup_64_no_verify+0x179/0x17b

-> #1 (&port_lock_key){-.-.}-{2:2}:
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0xb4/0x100 kernel/locking/spinlock.c:162
       serial8250_console_write+0x181/0x18b0 drivers/tty/serial/8250/8250_port.c:3439
       console_emit_next_record kernel/printk/printk.c:2944 [inline]
       console_flush_all+0x6ad/0xcf0 kernel/printk/printk.c:3000
       console_unlock+0xad/0x350 kernel/printk/printk.c:3069
       vprintk_emit+0x497/0x610 kernel/printk/printk.c:2341
       _printk+0xde/0x130 kernel/printk/printk.c:2366
       register_console+0xb96/0xf00 kernel/printk/printk.c:3583
       univ8250_console_init+0x45/0x50 drivers/tty/serial/8250/8250_core.c:717
       console_init+0x17b/0x5d0 kernel/printk/printk.c:3726
       start_kernel+0x2c8/0x4e0 init/main.c:982
       x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:555
       copy_bootdata+0x0/0xd0 arch/x86/kernel/head64.c:536
       secondary_startup_64_no_verify+0x179/0x17b

-> #0 (console_owner){-.-.}-{0:0}:
       check_prev_add kernel/locking/lockdep.c:3134 [inline]
       check_prevs_add kernel/locking/lockdep.c:3253 [inline]
       validate_chain kernel/locking/lockdep.c:3869 [inline]
       __lock_acquire+0x37ef/0x7d80 kernel/locking/lockdep.c:5137
       lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5754
       console_lock_spinning_enable kernel/printk/printk.c:1871 [inline]
       console_emit_next_record kernel/printk/printk.c:2938 [inline]
       console_flush_all+0x676/0xcf0 kernel/printk/printk.c:3000
       console_unlock+0xad/0x350 kernel/printk/printk.c:3069
       vprintk_emit+0x497/0x610 kernel/printk/printk.c:2341
       _printk+0xde/0x130 kernel/printk/printk.c:2366
       fail_dump lib/fault-inject.c:45 [inline]
       should_fail_ex+0x375/0x4c0 lib/fault-inject.c:153
       strncpy_from_user+0x36/0x2f0 lib/strncpy_from_user.c:118
       strncpy_from_user_nofault+0x71/0x140 mm/maccess.c:186
       bpf_probe_read_user_str_common kernel/trace/bpf_trace.c:212 [inline]
       ____bpf_probe_read_user_str kernel/trace/bpf_trace.c:221 [inline]
       bpf_probe_read_user_str+0x2a/0x70 kernel/trace/bpf_trace.c:218
       bpf_prog_c5968c940db16fdc+0x45/0x47
       bpf_dispatcher_nop_func include/linux/bpf.h:1224 [inline]
       __bpf_prog_run include/linux/filter.h:617 [inline]
       bpf_prog_run include/linux/filter.h:624 [inline]
       bpf_prog_run_array include/linux/bpf.h:1994 [inline]
       trace_call_bpf+0x333/0x6c0 kernel/trace/bpf_trace.c:143
       perf_trace_run_bpf_submit+0x7a/0x1c0 kernel/events/core.c:10287
       perf_trace_lock_acquire+0x342/0x400 include/trace/events/lock.h:24
       trace_lock_acquire include/trace/events/lock.h:24 [inline]
       lock_acquire+0x3ef/0x420 kernel/locking/lockdep.c:5725
       do_write_seqcount_begin_nested include/linux/seqlock.h:515 [inline]
       do_write_seqcount_begin include/linux/seqlock.h:541 [inline]
       psi_write_begin kernel/sched/psi.c:179 [inline]
       psi_account_irqtime+0x236/0x810 kernel/sched/psi.c:1034
       __schedule+0x8c8/0x4660 kernel/sched/core.c:6695
       preempt_schedule_notrace+0xdd/0x110 kernel/sched/core.c:6961
       preempt_schedule_notrace_thunk+0x1a/0x30 arch/x86/entry/thunk_64.S:46
       trace_lock_acquire include/trace/events/lock.h:24 [inline]
       lock_acquire+0x405/0x420 kernel/locking/lockdep.c:5725
       rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
       rcu_read_lock include/linux/rcupdate.h:786 [inline]
       aa_file_perm+0x138/0xee0 security/apparmor/file.c:600
       common_file_perm+0x18e/0x1f0 security/apparmor/lsm.c:522
       security_file_permission+0x69/0xa0 security/security.c:2622
       rw_verify_area fs/read_write.c:374 [inline]
       vfs_read+0x1e0/0x990 fs/read_write.c:461
       ksys_read+0x151/0x260 fs/read_write.c:613
       do_syscall_x64 arch/x86/entry/common.c:46 [inline]
       do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

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 ***

5 locks held by syz.0.5085/21120:
 #0: ffff888030b4aac8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2a3/0x330 fs/file.c:1040
 #1: ffff8880b8f3c298 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x29/0x130 kernel/sched/core.c:559
 #2: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
 #2: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
 #2: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: trace_call_bpf+0xc3/0x6c0 kernel/trace/bpf_trace.c:142
 #3: ffffffff8d126180 (console_lock){+.+.}-{0:0}, at: _printk+0xde/0x130 kernel/printk/printk.c:2366
 #4: ffffffff8d00d990 (console_srcu){....}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:339 [inline]
 #4: ffffffff8d00d990 (console_srcu){....}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:232 [inline]
 #4: ffffffff8d00d990 (console_srcu){....}-{0:0}, at: console_srcu_read_lock kernel/printk/printk.c:292 [inline]
 #4: ffffffff8d00d990 (console_srcu){....}-{0:0}, at: console_flush_all+0x10b/0xcf0 kernel/printk/printk.c:2992

stack backtrace:
CPU: 1 PID: 21120 Comm: syz.0.5085 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106
 check_noncircular+0x2fc/0x400 kernel/locking/lockdep.c:2187
 check_prev_add kernel/locking/lockdep.c:3134 [inline]
 check_prevs_add kernel/locking/lockdep.c:3253 [inline]
 validate_chain kernel/locking/lockdep.c:3869 [inline]
 __lock_acquire+0x37ef/0x7d80 kernel/locking/lockdep.c:5137
 lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5754
 console_lock_spinning_enable kernel/printk/printk.c:1871 [inline]
 console_emit_next_record kernel/printk/printk.c:2938 [inline]
 console_flush_all+0x676/0xcf0 kernel/printk/printk.c:3000
 console_unlock+0xad/0x350 kernel/printk/printk.c:3069
 vprintk_emit+0x497/0x610 kernel/printk/printk.c:2341
 _printk+0xde/0x130 kernel/printk/printk.c:2366
 fail_dump lib/fault-inject.c:45 [inline]
 should_fail_ex+0x375/0x4c0 lib/fault-inject.c:153
 strncpy_from_user+0x36/0x2f0 lib/strncpy_from_user.c:118
 strncpy_from_user_nofault+0x71/0x140 mm/maccess.c:186
 bpf_probe_read_user_str_common kernel/trace/bpf_trace.c:212 [inline]
 ____bpf_probe_read_user_str kernel/trace/bpf_trace.c:221 [inline]
 bpf_probe_read_user_str+0x2a/0x70 kernel/trace/bpf_trace.c:218
 bpf_prog_c5968c940db16fdc+0x45/0x47
 bpf_dispatcher_nop_func include/linux/bpf.h:1224 [inline]
 __bpf_prog_run include/linux/filter.h:617 [inline]
 bpf_prog_run include/linux/filter.h:624 [inline]
 bpf_prog_run_array include/linux/bpf.h:1994 [inline]
 trace_call_bpf+0x333/0x6c0 kernel/trace/bpf_trace.c:143
 perf_trace_run_bpf_submit+0x7a/0x1c0 kernel/events/core.c:10287
 perf_trace_lock_acquire+0x342/0x400 include/trace/events/lock.h:24
 trace_lock_acquire include/trace/events/lock.h:24 [inline]
 lock_acquire+0x3ef/0x420 kernel/locking/lockdep.c:5725
 do_write_seqcount_begin_nested include/linux/seqlock.h:515 [inline]
 do_write_seqcount_begin include/linux/seqlock.h:541 [inline]
 psi_write_begin kernel/sched/psi.c:179 [inline]
 psi_account_irqtime+0x236/0x810 kernel/sched/psi.c:1034
 __schedule+0x8c8/0x4660 kernel/sched/core.c:6695
 preempt_schedule_notrace+0xdd/0x110 kernel/sched/core.c:6961
 preempt_schedule_notrace_thunk+0x1a/0x30 arch/x86/entry/thunk_64.S:46
 trace_lock_acquire include/trace/events/lock.h:24 [inline]
 lock_acquire+0x405/0x420 kernel/locking/lockdep.c:5725
 rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
 rcu_read_lock include/linux/rcupdate.h:786 [inline]
 aa_file_perm+0x138/0xee0 security/apparmor/file.c:600
 common_file_perm+0x18e/0x1f0 security/apparmor/lsm.c:522
 security_file_permission+0x69/0xa0 security/security.c:2622
 rw_verify_area fs/read_write.c:374 [inline]
 vfs_read+0x1e0/0x990 fs/read_write.c:461
 ksys_read+0x151/0x260 fs/read_write.c:613
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f0f7715e90e
Code: 08 0f 85 a5 a8 ff ff 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 <c3> 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 80 00 00 00 00 48 83 ec 08
RSP: 002b:00007f0f7805ffe8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00007f0f780606c0 RCX: 00007f0f7715e90e
RDX: 000000000000000f RSI: 00007f0f780600a0 RDI: 0000000000000005
RBP: 00007f0f78060090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007f0f77426128 R14: 00007f0f77426090 R15: 00007ffd340f9c18
 </TASK>
CPU: 1 PID: 21120 Comm: syz.0.5085 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106
 fail_dump lib/fault-inject.c:52 [inline]
 should_fail_ex+0x394/0x4c0 lib/fault-inject.c:153
 strncpy_from_user+0x36/0x2f0 lib/strncpy_from_user.c:118
 strncpy_from_user_nofault+0x71/0x140 mm/maccess.c:186
 bpf_probe_read_user_str_common kernel/trace/bpf_trace.c:212 [inline]
 ____bpf_probe_read_user_str kernel/trace/bpf_trace.c:221 [inline]
 bpf_probe_read_user_str+0x2a/0x70 kernel/trace/bpf_trace.c:218
 bpf_prog_c5968c940db16fdc+0x45/0x47
 bpf_dispatcher_nop_func include/linux/bpf.h:1224 [inline]
 __bpf_prog_run include/linux/filter.h:617 [inline]
 bpf_prog_run include/linux/filter.h:624 [inline]
 bpf_prog_run_array include/linux/bpf.h:1994 [inline]
 trace_call_bpf+0x333/0x6c0 kernel/trace/bpf_trace.c:143
 perf_trace_run_bpf_submit+0x7a/0x1c0 kernel/events/core.c:10287
 perf_trace_lock_acquire+0x342/0x400 include/trace/events/lock.h:24
 trace_lock_acquire include/trace/events/lock.h:24 [inline]
 lock_acquire+0x3ef/0x420 kernel/locking/lockdep.c:5725
 do_write_seqcount_begin_nested include/linux/seqlock.h:515 [inline]
 do_write_seqcount_begin include/linux/seqlock.h:541 [inline]
 psi_write_begin kernel/sched/psi.c:179 [inline]
 psi_account_irqtime+0x236/0x810 kernel/sched/psi.c:1034
 __schedule+0x8c8/0x4660 kernel/sched/core.c:6695
 preempt_schedule_notrace+0xdd/0x110 kernel/sched/core.c:6961
 preempt_schedule_notrace_thunk+0x1a/0x30 arch/x86/entry/thunk_64.S:46
 trace_lock_acquire include/trace/events/lock.h:24 [inline]
 lock_acquire+0x405/0x420 kernel/locking/lockdep.c:5725
 rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
 rcu_read_lock include/linux/rcupdate.h:786 [inline]
 aa_file_perm+0x138/0xee0 security/apparmor/file.c:600
 common_file_perm+0x18e/0x1f0 security/apparmor/lsm.c:522
 security_file_permission+0x69/0xa0 security/security.c:2622
 rw_verify_area fs/read_write.c:374 [inline]
 vfs_read+0x1e0/0x990 fs/read_write.c:461
 ksys_read+0x151/0x260 fs/read_write.c:613
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f0f7715e90e
Code: 08 0f 85 a5 a8 ff ff 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 <c3> 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 80 00 00 00 00 48 83 ec 08
RSP: 002b:00007f0f7805ffe8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00007f0f780606c0 RCX: 00007f0f7715e90e
RDX: 000000000000000f RSI: 00007f0f780600a0 RDI: 0000000000000005
RBP: 00007f0f78060090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007f0f77426128 R14: 00007f0f77426090 R15: 00007ffd340f9c18
 </TASK>