FAULT_INJECTION: forcing a failure.
name fail_usercopy, interval 1, probability 0, space 0, times 0
======================================================
WARNING: possible circular locking dependency detected
5.15.169-syzkaller #0 Not tainted
------------------------------------------------------
syz.4.2640/15132 is trying to acquire lock:
ffffffff8c9147e0 (console_owner){-.-.}-{0:0}, at: console_lock_spinning_enable+0x2c/0x60 kernel/printk/printk.c:1802

but task is already holding lock:
ffff8880b913a318 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 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}:
       lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623
       _raw_spin_lock_nested+0x2d/0x40 kernel/locking/spinlock.c:368
       raw_spin_rq_lock_nested+0x26/0x140 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+0x5d/0x350 kernel/sched/fair.c:11484
       sched_cgroup_fork+0x2d3/0x330 kernel/sched/core.c:4463
       copy_process+0x224a/0x3ef0 kernel/fork.c:2317
       kernel_clone+0x210/0x960 kernel/fork.c:2601
       kernel_thread+0x168/0x1e0 kernel/fork.c:2653
       rest_init+0x21/0x330 init/main.c:706
       start_kernel+0x48c/0x540 init/main.c:1140
       secondary_startup_64_no_verify+0xb1/0xbb

-> #3 (&p->pi_lock){-.-.}-{2:2}:
       lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162
       try_to_wake_up+0xae/0x1300 kernel/sched/core.c:4027
       __pollwake fs/select.c:207 [inline]
       pollwake+0x1d0/0x280 fs/select.c:217
       __wake_up_common+0x2a0/0x4e0 kernel/sched/wait.c:108
       __wake_up_common_lock kernel/sched/wait.c:138 [inline]
       __wake_up+0x112/0x1c0 kernel/sched/wait.c:157
       n_tty_set_termios+0xcb7/0x10f0 drivers/tty/n_tty.c:1817
       tty_set_termios+0xda3/0x1640 drivers/tty/tty_ioctl.c:365
       set_termios+0x6ce/0x990 drivers/tty/tty_ioctl.c:458
       tty_mode_ioctl+0x6f7/0x980
       tty_ioctl+0x8ff/0xc50 drivers/tty/tty_io.c:2819
       vfs_ioctl fs/ioctl.c:51 [inline]
       __do_sys_ioctl fs/ioctl.c:874 [inline]
       __se_sys_ioctl+0xf1/0x160 fs/ioctl.c:860
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x66/0xd0

-> #2 (&tty->write_wait){-...}-{2:2}:
       lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162
       __wake_up_common_lock kernel/sched/wait.c:137 [inline]
       __wake_up+0xf5/0x1c0 kernel/sched/wait.c:157
       tty_port_default_wakeup+0xa8/0x100 drivers/tty/tty_port.c:51
       serial8250_tx_chars+0x60d/0x800 drivers/tty/serial/8250/8250_port.c:1828
       serial8250_handle_irq+0x505/0x600 drivers/tty/serial/8250/8250_port.c:1924
       serial8250_default_handle_irq+0xc8/0x1e0 drivers/tty/serial/8250/8250_port.c:1941
       serial8250_interrupt+0xa1/0x1e0 drivers/tty/serial/8250/8250_core.c:127
       __handle_irq_event_percpu+0x292/0xa70 kernel/irq/handle.c:156
       handle_irq_event_percpu kernel/irq/handle.c:196 [inline]
       handle_irq_event+0xff/0x2b0 kernel/irq/handle.c:213
       handle_edge_irq+0x245/0xbf0 kernel/irq/chip.c:819
       generic_handle_irq_desc include/linux/irqdesc.h:158 [inline]
       handle_irq arch/x86/kernel/irq.c:231 [inline]
       __common_interrupt+0xd7/0x1f0 arch/x86/kernel/irq.c:250
       common_interrupt+0xae/0xd0 arch/x86/kernel/irq.c:240
       asm_common_interrupt+0x22/0x40 arch/x86/include/asm/idtentry.h:667
       __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [inline]
       _raw_spin_unlock_irqrestore+0xd4/0x130 kernel/locking/spinlock.c:194
       spin_unlock_irqrestore include/linux/spinlock.h:418 [inline]
       uart_write+0x6af/0x930 drivers/tty/serial/serial_core.c:590
       process_output_block drivers/tty/n_tty.c:592 [inline]
       n_tty_write+0xd7e/0x1280 drivers/tty/n_tty.c:2339
       do_tty_write drivers/tty/tty_io.c:1038 [inline]
       file_tty_write+0x561/0x920 drivers/tty/tty_io.c:1110
       call_write_iter include/linux/fs.h:2174 [inline]
       new_sync_write fs/read_write.c:507 [inline]
       vfs_write+0xacd/0xe50 fs/read_write.c:594
       ksys_write+0x1a2/0x2c0 fs/read_write.c:647
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x66/0xd0

-> #1 (&port_lock_key){-.-.}-{2:2}:
       lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162
       serial8250_console_write+0x19d/0x1180 drivers/tty/serial/8250/8250_port.c:3354
       console_unlock+0xced/0x12b0 kernel/printk/printk.c:2744
       vprintk_emit+0xbf/0x150 kernel/printk/printk.c:2274
       _printk+0xd1/0x120 kernel/printk/printk.c:2299
       register_console+0x65a/0x940 kernel/printk/printk.c:3107
       univ8250_console_init+0x41/0x50 drivers/tty/serial/8250/8250_core.c:690
       console_init+0x18c/0x660 kernel/printk/printk.c:3207
       start_kernel+0x301/0x540 init/main.c:1076
       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+0x1649/0x5930 kernel/locking/lockdep.c:3788
       __lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5012
       lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623
       console_lock_spinning_enable+0x51/0x60 kernel/printk/printk.c:1805
       console_unlock+0xa47/0x12b0 kernel/printk/printk.c:2741
       vprintk_emit+0xbf/0x150 kernel/printk/printk.c:2274
       _printk+0xd1/0x120 kernel/printk/printk.c:2299
       fail_dump lib/fault-inject.c:45 [inline]
       should_fail+0x36c/0x4c0 lib/fault-inject.c:146
       strncpy_from_user+0x32/0x370 lib/strncpy_from_user.c:118
       strncpy_from_user_nofault+0x6c/0x130 mm/maccess.c:295
       bpf_probe_read_user_str_common kernel/trace/bpf_trace.c:194 [inline]
       ____bpf_probe_read_compat_str kernel/trace/bpf_trace.c:300 [inline]
       bpf_probe_read_compat_str+0xe4/0x180 kernel/trace/bpf_trace.c:296
       bpf_prog_e42f6260c1b72fb3+0x35/0x5f8
       bpf_dispatcher_nop_func include/linux/bpf.h:790 [inline]
       __bpf_prog_run include/linux/filter.h:628 [inline]
       bpf_prog_run include/linux/filter.h:635 [inline]
       __bpf_trace_run kernel/trace/bpf_trace.c:1880 [inline]
       bpf_trace_run3+0x1d1/0x380 kernel/trace/bpf_trace.c:1918
       __traceiter_sched_switch+0x7d/0xb0 include/trace/events/sched.h:220
       trace_sched_switch include/trace/events/sched.h:220 [inline]
       __schedule+0x1e8d/0x45b0 kernel/sched/core.c:6370
       schedule+0x11b/0x1f0 kernel/sched/core.c:6456
       exit_to_user_mode_loop+0x44/0x130 kernel/entry/common.c:169
       exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:214
       irqentry_exit_to_user_mode+0x5/0x30 kernel/entry/common.c:320
       asm_sysvec_reschedule_ipi+0x16/0x20 arch/x86/include/asm/idtentry.h:681

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.4.2640/15132:
 #0: ffff8880b913a318 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:475
 #1: ffffffff8c91fc60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:311
 #2: ffffffff8c7fc520 (console_lock){+.+.}-{0:0}, at: vprintk_emit+0xa6/0x150 kernel/printk/printk.c:2273

stack backtrace:
CPU: 1 PID: 15132 Comm: syz.4.2640 Not tainted 5.15.169-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106
 check_noncircular+0x2f8/0x3b0 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+0x1649/0x5930 kernel/locking/lockdep.c:3788
 __lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5012
 lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623
 console_lock_spinning_enable+0x51/0x60 kernel/printk/printk.c:1805
 console_unlock+0xa47/0x12b0 kernel/printk/printk.c:2741
 vprintk_emit+0xbf/0x150 kernel/printk/printk.c:2274
 _printk+0xd1/0x120 kernel/printk/printk.c:2299
 fail_dump lib/fault-inject.c:45 [inline]
 should_fail+0x36c/0x4c0 lib/fault-inject.c:146
 strncpy_from_user+0x32/0x370 lib/strncpy_from_user.c:118
 strncpy_from_user_nofault+0x6c/0x130 mm/maccess.c:295
 bpf_probe_read_user_str_common kernel/trace/bpf_trace.c:194 [inline]
 ____bpf_probe_read_compat_str kernel/trace/bpf_trace.c:300 [inline]
 bpf_probe_read_compat_str+0xe4/0x180 kernel/trace/bpf_trace.c:296
 bpf_prog_e42f6260c1b72fb3+0x35/0x5f8
 bpf_dispatcher_nop_func include/linux/bpf.h:790 [inline]
 __bpf_prog_run include/linux/filter.h:628 [inline]
 bpf_prog_run include/linux/filter.h:635 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:1880 [inline]
 bpf_trace_run3+0x1d1/0x380 kernel/trace/bpf_trace.c:1918
 __traceiter_sched_switch+0x7d/0xb0 include/trace/events/sched.h:220
 trace_sched_switch include/trace/events/sched.h:220 [inline]
 __schedule+0x1e8d/0x45b0 kernel/sched/core.c:6370
 schedule+0x11b/0x1f0 kernel/sched/core.c:6456
 exit_to_user_mode_loop+0x44/0x130 kernel/entry/common.c:169
 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:214
 irqentry_exit_to_user_mode+0x5/0x30 kernel/entry/common.c:320
 asm_sysvec_reschedule_ipi+0x16/0x20 arch/x86/include/asm/idtentry.h:681
RIP: 0033:0x7efe3a42e36a
Code: 80 3d 95 d3 e1 00 00 0f 84 9b 00 00 00 53 48 89 fb 48 85 ff 74 1a 80 3d 5b 9d 2e 00 00 75 33 48 8b 43 10 48 c7 00 00 00 00 00 <5b> c3 0f 1f 40 00 64 48 8b 1c 25 c0 fe ff ff 48 85 db 0f 84 85 00
RSP: 002b:00007efe3899a050 EFLAGS: 00000246
RAX: 00007efe399e1000 RBX: 00007efe3a71c1c8 RCX: 0000000000000000
RDX: 00007efe3899a090 RSI: 00007efe3899a090 RDI: 00007efe3a71c1c8
RBP: 00007efe3899a090 R08: 0000000000000000 R09: 00007efe38999df7
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000001
R13: 0000000000000000 R14: 00007efe3a71c130 R15: 00007ffe57fca458
 </TASK>
CPU: 1 PID: 15132 Comm: syz.4.2640 Not tainted 5.15.169-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106
 fail_dump lib/fault-inject.c:52 [inline]
 should_fail+0x38a/0x4c0 lib/fault-inject.c:146
 strncpy_from_user+0x32/0x370 lib/strncpy_from_user.c:118
 strncpy_from_user_nofault+0x6c/0x130 mm/maccess.c:295
 bpf_probe_read_user_str_common kernel/trace/bpf_trace.c:194 [inline]
 ____bpf_probe_read_compat_str kernel/trace/bpf_trace.c:300 [inline]
 bpf_probe_read_compat_str+0xe4/0x180 kernel/trace/bpf_trace.c:296
 bpf_prog_e42f6260c1b72fb3+0x35/0x5f8
 bpf_dispatcher_nop_func include/linux/bpf.h:790 [inline]
 __bpf_prog_run include/linux/filter.h:628 [inline]
 bpf_prog_run include/linux/filter.h:635 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:1880 [inline]
 bpf_trace_run3+0x1d1/0x380 kernel/trace/bpf_trace.c:1918
 __traceiter_sched_switch+0x7d/0xb0 include/trace/events/sched.h:220
 trace_sched_switch include/trace/events/sched.h:220 [inline]
 __schedule+0x1e8d/0x45b0 kernel/sched/core.c:6370
 schedule+0x11b/0x1f0 kernel/sched/core.c:6456
 exit_to_user_mode_loop+0x44/0x130 kernel/entry/common.c:169
 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:214
 irqentry_exit_to_user_mode+0x5/0x30 kernel/entry/common.c:320
 asm_sysvec_reschedule_ipi+0x16/0x20 arch/x86/include/asm/idtentry.h:681
RIP: 0033:0x7efe3a42e36a
Code: 80 3d 95 d3 e1 00 00 0f 84 9b 00 00 00 53 48 89 fb 48 85 ff 74 1a 80 3d 5b 9d 2e 00 00 75 33 48 8b 43 10 48 c7 00 00 00 00 00 <5b> c3 0f 1f 40 00 64 48 8b 1c 25 c0 fe ff ff 48 85 db 0f 84 85 00
RSP: 002b:00007efe3899a050 EFLAGS: 00000246
RAX: 00007efe399e1000 RBX: 00007efe3a71c1c8 RCX: 0000000000000000
RDX: 00007efe3899a090 RSI: 00007efe3899a090 RDI: 00007efe3a71c1c8
RBP: 00007efe3899a090 R08: 0000000000000000 R09: 00007efe38999df7
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000001
R13: 0000000000000000 R14: 00007efe3a71c130 R15: 00007ffe57fca458
 </TASK>