FAULT_INJECTION: forcing a failure.
name fail_usercopy, interval 1, probability 0, space 0, times 0
======================================================
WARNING: possible circular locking dependency detected
6.14.0-syzkaller-g8582d9ab3efd #0 Not tainted
------------------------------------------------------
syz.1.506/7816 is trying to acquire lock:
ffffffff8ec19a60 (console_owner){-.-.}-{0:0}, at: console_trylock_spinning kernel/printk/printk.c:2048 [inline]
ffffffff8ec19a60 (console_owner){-.-.}-{0:0}, at: vprintk_emit+0x552/0xa40 kernel/printk/printk.c:2449

but task is already holding lock:
ffff8880b8739b18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:605

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #4 (&rq->__lock){-.-.}-{2:2}:
       lock_acquire+0x116/0x2f0 kernel/locking/lockdep.c:5866
       _raw_spin_lock_nested+0x31/0x40 kernel/locking/spinlock.c:378
       raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:605
       raw_spin_rq_lock kernel/sched/sched.h:1513 [inline]
       task_rq_lock+0xcb/0x440 kernel/sched/core.c:707
       cgroup_move_task+0x9b/0x660 kernel/sched/psi.c:1161
       css_set_move_task+0x72e/0x950 kernel/cgroup/cgroup.c:911
       cgroup_post_fork+0x27f/0x8c0 kernel/cgroup/cgroup.c:6709
       copy_process+0x39b5/0x3d10 kernel/fork.c:2658
       kernel_clone+0x242/0x930 kernel/fork.c:2844
       user_mode_thread+0x148/0x1c0 kernel/fork.c:2922
       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:513
       x86_64_start_kernel+0x66/0x70 arch/x86/kernel/head64.c:494
       common_startup_64+0x13e/0x147

-> #3 (&p->pi_lock){-.-.}-{2:2}:
       lock_acquire+0x116/0x2f0 kernel/locking/lockdep.c:5866
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0xd8/0x130 kernel/locking/spinlock.c:162
       class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:557 [inline]
       try_to_wake_up+0xc6/0x15d0 kernel/sched/core.c:4212
       __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:1842
       serial8250_handle_irq+0x631/0xb80 drivers/tty/serial/8250/8250_port.c:1950
       serial8250_default_handle_irq+0xd1/0x1f0 drivers/tty/serial/8250/8250_port.c:1970
       serial8250_interrupt+0xa9/0x1f0 drivers/tty/serial/8250/8250_core.c:86
       __handle_irq_event_percpu+0x29c/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:254 [inline]
       call_irq_handler arch/x86/kernel/irq.c:266 [inline]
       __common_interrupt+0x136/0x230 arch/x86/kernel/irq.c:292
       common_interrupt+0x5e/0xd0 arch/x86/kernel/irq.c:285
       asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:693
       native_irq_enable arch/x86/include/asm/irqflags.h:-1 [inline]
       arch_local_irq_enable arch/x86/include/asm/irqflags.h:119 [inline]
       handle_softirqs+0x1f1/0x9b0 kernel/softirq.c:563
       __do_softirq kernel/softirq.c:613 [inline]
       invoke_softirq kernel/softirq.c:453 [inline]
       __irq_exit_rcu+0xfb/0x220 kernel/softirq.c:680
       irq_exit_rcu+0x9/0x30 kernel/softirq.c:696
       instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline]
       sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1049
       asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
       native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline]
       pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:80
       arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
       default_idle+0x13/0x20 arch/x86/kernel/process.c:748
       default_idle_call+0x74/0xb0 kernel/sched/idle.c:117
       cpuidle_idle_call kernel/sched/idle.c:185 [inline]
       do_idle+0x22e/0x5d0 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:513
       x86_64_start_kernel+0x66/0x70 arch/x86/kernel/head64.c:494
       common_startup_64+0x13e/0x147

-> #2 (&tty->write_wait){-.-.}-{3:3}:
       lock_acquire+0x116/0x2f0 kernel/locking/lockdep.c:5866
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0xd8/0x130 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:1842
       serial8250_handle_irq+0x631/0xb80 drivers/tty/serial/8250/8250_port.c:1950
       serial8250_default_handle_irq+0xd1/0x1f0 drivers/tty/serial/8250/8250_port.c:1970
       serial8250_interrupt+0xa9/0x1f0 drivers/tty/serial/8250/8250_core.c:86
       __handle_irq_event_percpu+0x29c/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:254 [inline]
       call_irq_handler arch/x86/kernel/irq.c:266 [inline]
       __common_interrupt+0x136/0x230 arch/x86/kernel/irq.c:292
       common_interrupt+0x5e/0xd0 arch/x86/kernel/irq.c:285
       asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:693
       native_irq_enable arch/x86/include/asm/irqflags.h:-1 [inline]
       arch_local_irq_enable arch/x86/include/asm/irqflags.h:119 [inline]
       handle_softirqs+0x1f1/0x9b0 kernel/softirq.c:563
       __do_softirq kernel/softirq.c:613 [inline]
       invoke_softirq kernel/softirq.c:453 [inline]
       __irq_exit_rcu+0xfb/0x220 kernel/softirq.c:680
       irq_exit_rcu+0x9/0x30 kernel/softirq.c:696
       instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline]
       sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1049
       asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
       native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline]
       pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:80
       arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
       default_idle+0x13/0x20 arch/x86/kernel/process.c:748
       default_idle_call+0x74/0xb0 kernel/sched/idle.c:117
       cpuidle_idle_call kernel/sched/idle.c:185 [inline]
       do_idle+0x22e/0x5d0 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:513
       x86_64_start_kernel+0x66/0x70 arch/x86/kernel/head64.c:494
       common_startup_64+0x13e/0x147

-> #1 (&port_lock_key){-.-.}-{3:3}:
       lock_acquire+0x116/0x2f0 kernel/locking/lockdep.c:5866
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0xd8/0x130 kernel/locking/spinlock.c:162
       uart_port_lock_irqsave include/linux/serial_core.h:715 [inline]
       serial8250_console_write+0x1b0/0x1e00 drivers/tty/serial/8250/8250_port.c:3415
       console_emit_next_record kernel/printk/printk.c:3138 [inline]
       console_flush_all+0x86d/0xec0 kernel/printk/printk.c:3226
       __console_flush_and_unlock kernel/printk/printk.c:3285 [inline]
       console_unlock+0x151/0x3b0 kernel/printk/printk.c:3325
       vprintk_emit+0x761/0xa40 kernel/printk/printk.c:2450
       _printk+0xd5/0x120 kernel/printk/printk.c:2475
       register_console+0xc7b/0x1080 kernel/printk/printk.c:4125
       univ8250_console_init+0x52/0x90 drivers/tty/serial/8250/8250_core.c:513
       console_init+0x1b8/0x6f0 kernel/printk/printk.c:4323
       start_kernel+0x2dd/0x510 init/main.c:1034
       x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:513
       x86_64_start_kernel+0x66/0x70 arch/x86/kernel/head64.c:494
       common_startup_64+0x13e/0x147

-> #0 (console_owner){-.-.}-{0:0}:
       check_prev_add kernel/locking/lockdep.c:3166 [inline]
       check_prevs_add kernel/locking/lockdep.c:3285 [inline]
       validate_chain+0xa69/0x24e0 kernel/locking/lockdep.c:3909
       __lock_acquire+0xad5/0xd80 kernel/locking/lockdep.c:5235
       lock_acquire+0x116/0x2f0 kernel/locking/lockdep.c:5866
       console_trylock_spinning kernel/printk/printk.c:2048 [inline]
       vprintk_emit+0x56f/0xa40 kernel/printk/printk.c:2449
       _printk+0xd5/0x120 kernel/printk/printk.c:2475
       fail_dump lib/fault-inject.c:66 [inline]
       should_fail_ex+0x405/0x570 lib/fault-inject.c:174
       strncpy_from_user+0x36/0x280 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_b288f06f4ef8c576+0x75/0x79
       bpf_dispatcher_nop_func include/linux/bpf.h:1316 [inline]
       __bpf_prog_run include/linux/filter.h:709 [inline]
       bpf_prog_run include/linux/filter.h:725 [inline]
       __bpf_trace_run kernel/trace/bpf_trace.c:2363 [inline]
       bpf_trace_run2+0x48a/0x550 kernel/trace/bpf_trace.c:2404
       __bpf_trace_tlb_flush+0x176/0x230 include/trace/events/tlb.h:38
       __do_trace_tlb_flush include/trace/events/tlb.h:38 [inline]
       trace_tlb_flush+0x11c/0x140 include/trace/events/tlb.h:38
       switch_mm_irqs_off+0x5da/0xb00 arch/x86/mm/tlb.c:-1
       context_switch kernel/sched/core.c:5366 [inline]
       __schedule+0x13a1/0x5240 kernel/sched/core.c:6767
       __schedule_loop kernel/sched/core.c:6845 [inline]
       schedule+0x163/0x360 kernel/sched/core.c:6860
       __lock_sock+0x1cf/0x340 net/core/sock.c:3134
       lock_sock_nested+0x9e/0x100 net/core/sock.c:3702
       lock_sock include/net/sock.h:1615 [inline]
       tcp_sendmsg+0x22/0x50 net/ipv4/tcp.c:1365
       sock_sendmsg_nosec net/socket.c:712 [inline]
       __sock_sendmsg+0x1a6/0x270 net/socket.c:727
       ____sys_sendmsg+0x523/0x860 net/socket.c:2566
       ___sys_sendmsg net/socket.c:2620 [inline]
       __sys_sendmsg+0x271/0x360 net/socket.c:2652
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0xf3/0x210 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 ***

3 locks held by syz.1.506/7816:
 #0: ffff88805f737518 (sk_lock-AF_INET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1615 [inline]
 #0: ffff88805f737518 (sk_lock-AF_INET){+.+.}-{0:0}, at: tcp_sendmsg+0x22/0x50 net/ipv4/tcp.c:1365
 #1: ffff8880b8739b18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:605
 #2: ffffffff8ed3df60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #2: ffffffff8ed3df60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
 #2: ffffffff8ed3df60 (rcu_read_lock){....}-{1:3}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2362 [inline]
 #2: ffffffff8ed3df60 (rcu_read_lock){....}-{1:3}, at: bpf_trace_run2+0x1fe/0x550 kernel/trace/bpf_trace.c:2404

stack backtrace:
CPU: 1 UID: 0 PID: 7816 Comm: syz.1.506 Not tainted 6.14.0-syzkaller-g8582d9ab3efd #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 print_circular_bug+0x2e1/0x300 kernel/locking/lockdep.c:2079
 check_noncircular+0x142/0x160 kernel/locking/lockdep.c:2211
 check_prev_add kernel/locking/lockdep.c:3166 [inline]
 check_prevs_add kernel/locking/lockdep.c:3285 [inline]
 validate_chain+0xa69/0x24e0 kernel/locking/lockdep.c:3909
 __lock_acquire+0xad5/0xd80 kernel/locking/lockdep.c:5235
 lock_acquire+0x116/0x2f0 kernel/locking/lockdep.c:5866
 console_trylock_spinning kernel/printk/printk.c:2048 [inline]
 vprintk_emit+0x56f/0xa40 kernel/printk/printk.c:2449
 _printk+0xd5/0x120 kernel/printk/printk.c:2475
 fail_dump lib/fault-inject.c:66 [inline]
 should_fail_ex+0x405/0x570 lib/fault-inject.c:174
 strncpy_from_user+0x36/0x280 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_b288f06f4ef8c576+0x75/0x79
 bpf_dispatcher_nop_func include/linux/bpf.h:1316 [inline]
 __bpf_prog_run include/linux/filter.h:709 [inline]
 bpf_prog_run include/linux/filter.h:725 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:2363 [inline]
 bpf_trace_run2+0x48a/0x550 kernel/trace/bpf_trace.c:2404
 __bpf_trace_tlb_flush+0x176/0x230 include/trace/events/tlb.h:38
 __do_trace_tlb_flush include/trace/events/tlb.h:38 [inline]
 trace_tlb_flush+0x11c/0x140 include/trace/events/tlb.h:38
 switch_mm_irqs_off+0x5da/0xb00 arch/x86/mm/tlb.c:-1
 context_switch kernel/sched/core.c:5366 [inline]
 __schedule+0x13a1/0x5240 kernel/sched/core.c:6767
 __schedule_loop kernel/sched/core.c:6845 [inline]
 schedule+0x163/0x360 kernel/sched/core.c:6860
 __lock_sock+0x1cf/0x340 net/core/sock.c:3134
 lock_sock_nested+0x9e/0x100 net/core/sock.c:3702
 lock_sock include/net/sock.h:1615 [inline]
 tcp_sendmsg+0x22/0x50 net/ipv4/tcp.c:1365
 sock_sendmsg_nosec net/socket.c:712 [inline]
 __sock_sendmsg+0x1a6/0x270 net/socket.c:727
 ____sys_sendmsg+0x523/0x860 net/socket.c:2566
 ___sys_sendmsg net/socket.c:2620 [inline]
 __sys_sendmsg+0x271/0x360 net/socket.c:2652
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xf3/0x210 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f934418e169
Code: Unable to access opcode bytes at 0x7f934418e13f.
RSP: 002b:00007f9341ff6038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f93443b6080 RCX: 00007f934418e169
RDX: 0000000000008880 RSI: 0000200000000900 RDI: 0000000000000003
RBP: 00007f9341ff6090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 0000000000000001 R14: 00007f93443b6080 R15: 00007ffe64b5fc08
 </TASK>
CPU: 1 UID: 0 PID: 7816 Comm: syz.1.506 Not tainted 6.14.0-syzkaller-g8582d9ab3efd #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
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+0x424/0x570 lib/fault-inject.c:174
 strncpy_from_user+0x36/0x280 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_b288f06f4ef8c576+0x75/0x79
 bpf_dispatcher_nop_func include/linux/bpf.h:1316 [inline]
 __bpf_prog_run include/linux/filter.h:709 [inline]
 bpf_prog_run include/linux/filter.h:725 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:2363 [inline]
 bpf_trace_run2+0x48a/0x550 kernel/trace/bpf_trace.c:2404
 __bpf_trace_tlb_flush+0x176/0x230 include/trace/events/tlb.h:38
 __do_trace_tlb_flush include/trace/events/tlb.h:38 [inline]
 trace_tlb_flush+0x11c/0x140 include/trace/events/tlb.h:38
 switch_mm_irqs_off+0x5da/0xb00 arch/x86/mm/tlb.c:-1
 context_switch kernel/sched/core.c:5366 [inline]
 __schedule+0x13a1/0x5240 kernel/sched/core.c:6767
 __schedule_loop kernel/sched/core.c:6845 [inline]
 schedule+0x163/0x360 kernel/sched/core.c:6860
 __lock_sock+0x1cf/0x340 net/core/sock.c:3134
 lock_sock_nested+0x9e/0x100 net/core/sock.c:3702
 lock_sock include/net/sock.h:1615 [inline]
 tcp_sendmsg+0x22/0x50 net/ipv4/tcp.c:1365
 sock_sendmsg_nosec net/socket.c:712 [inline]
 __sock_sendmsg+0x1a6/0x270 net/socket.c:727
 ____sys_sendmsg+0x523/0x860 net/socket.c:2566
 ___sys_sendmsg net/socket.c:2620 [inline]
 __sys_sendmsg+0x271/0x360 net/socket.c:2652
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xf3/0x210 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f934418e169
Code: Unable to access opcode bytes at 0x7f934418e13f.
RSP: 002b:00007f9341ff6038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f93443b6080 RCX: 00007f934418e169
RDX: 0000000000008880 RSI: 0000200000000900 RDI: 0000000000000003
RBP: 00007f9341ff6090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 0000000000000001 R14: 00007f93443b6080 R15: 00007ffe64b5fc08
 </TASK>