FAULT_INJECTION: forcing a failure. name fail_usercopy, interval 1, probability 0, space 0, times 0 ====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Tainted: G L ------------------------------------------------------ syz.3.2087/13644 is trying to acquire lock: ffffffff8e2d6ac0 (console_owner){-.-.}-{0:0}, at: console_lock_spinning_enable+0x61/0x80 kernel/printk/printk.c:1900 but task is already holding lock: ffff88802b23add8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:647 [inline] ffff88802b23add8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x7e/0x130 kernel/sched/core.c:632 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+0x31/0x40 kernel/locking/spinlock.c:378 raw_spin_rq_lock_nested+0x29/0x130 kernel/sched/core.c:639 raw_spin_rq_lock kernel/sched/sched.h:1558 [inline] task_rq_lock+0xcf/0x490 kernel/sched/core.c:739 cgroup_move_task+0x81/0x2a0 kernel/sched/psi.c:1170 css_set_move_task+0x288/0x5f0 kernel/cgroup/cgroup.c:951 cgroup_post_fork+0x201/0x9e0 kernel/cgroup/cgroup.c:6913 copy_process+0x56b6/0x7430 kernel/fork.c:2465 kernel_clone+0xfc/0x910 kernel/fork.c:2651 user_mode_thread+0xc8/0x110 kernel/fork.c:2727 rest_init+0x23/0x2b0 init/main.c:722 start_kernel+0x3ef/0x4d0 init/main.c:1206 x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:310 x86_64_start_kernel+0x130/0x190 arch/x86/kernel/head64.c:291 common_startup_64+0x13e/0x148 -> #3 (&p->pi_lock){-.-.}-{2:2}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162 class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:557 [inline] try_to_wake_up+0xb7/0x1860 kernel/sched/core.c:4106 __wake_up_common+0x135/0x1f0 kernel/sched/wait.c:108 __wake_up_common_lock kernel/sched/wait.c:125 [inline] __wake_up+0x31/0x60 kernel/sched/wait.c:146 tty_port_default_wakeup+0x4d/0x60 drivers/tty/tty_port.c:67 serial8250_tx_chars+0x68e/0x860 drivers/tty/serial/8250/8250_port.c:1719 serial8250_handle_irq+0x761/0xcb0 drivers/tty/serial/8250/8250_port.c:1827 serial8250_default_handle_irq+0x9e/0x270 drivers/tty/serial/8250/8250_port.c:1846 serial8250_interrupt+0xf8/0x1d0 drivers/tty/serial/8250/8250_core.c:86 __handle_irq_event_percpu+0x236/0x890 kernel/irq/handle.c:211 handle_irq_event_percpu kernel/irq/handle.c:248 [inline] handle_irq_event+0xab/0x1e0 kernel/irq/handle.c:265 handle_edge_irq+0x3ca/0x9e0 kernel/irq/chip.c:855 generic_handle_irq_desc include/linux/irqdesc.h:172 [inline] handle_irq arch/x86/kernel/irq.c:255 [inline] call_irq_handler arch/x86/kernel/irq.c:311 [inline] __common_interrupt+0xd0/0x2f0 arch/x86/kernel/irq.c:326 common_interrupt+0xba/0xe0 arch/x86/kernel/irq.c:319 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:688 native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline] pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:81 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:767 default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:191 [inline] do_idle+0x38d/0x510 kernel/sched/idle.c:332 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:430 start_secondary+0x21d/0x2d0 arch/x86/kernel/smpboot.c:312 common_startup_64+0x13e/0x148 -> #2 (&tty->write_wait){-...}-{3:3}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162 __wake_up_common_lock kernel/sched/wait.c:124 [inline] __wake_up+0x1c/0x60 kernel/sched/wait.c:146 tty_port_default_wakeup+0x4d/0x60 drivers/tty/tty_port.c:67 serial8250_tx_chars+0x68e/0x860 drivers/tty/serial/8250/8250_port.c:1719 __start_tx+0x3df/0x490 drivers/tty/serial/8250/8250_port.c:1426 serial8250_start_tx+0x368/0x530 drivers/tty/serial/8250/8250_port.c:1535 __uart_start+0x295/0x500 drivers/tty/serial/serial_core.c:161 uart_write+0x218/0xb30 drivers/tty/serial/serial_core.c:633 process_output_block drivers/tty/n_tty.c:557 [inline] n_tty_write+0x434/0x1280 drivers/tty/n_tty.c:2366 iterate_tty_write drivers/tty/tty_io.c:1006 [inline] file_tty_write.constprop.0+0x503/0x9b0 drivers/tty/tty_io.c:1081 tty_write drivers/tty/tty_io.c:1102 [inline] redirected_tty_write drivers/tty/tty_io.c:1125 [inline] redirected_tty_write+0xd4/0x120 drivers/tty/tty_io.c:1105 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x7d3/0x11d0 fs/read_write.c:686 ksys_write+0x12a/0x250 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #1 (&port_lock_key){-.-.}-{3:3}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162 uart_port_lock_irqsave include/linux/serial_core.h:717 [inline] serial8250_console_write+0x181/0x1890 drivers/tty/serial/8250/8250_port.c:3301 console_emit_next_record kernel/printk/printk.c:3129 [inline] console_flush_one_record+0x796/0xc60 kernel/printk/printk.c:3215 console_flush_all kernel/printk/printk.c:3289 [inline] __console_flush_and_unlock kernel/printk/printk.c:3319 [inline] console_unlock+0xef/0x240 kernel/printk/printk.c:3359 vprintk_emit+0x407/0x6b0 kernel/printk/printk.c:2426 _printk+0xc7/0x100 kernel/printk/printk.c:2451 register_console+0x823/0x1210 kernel/printk/printk.c:4170 univ8250_console_init+0x5f/0x90 drivers/tty/serial/8250/8250_core.c:515 console_init+0x152/0x600 kernel/printk/printk.c:4369 start_kernel+0x298/0x4d0 init/main.c:1143 x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:310 x86_64_start_kernel+0x130/0x190 arch/x86/kernel/head64.c:291 common_startup_64+0x13e/0x148 -> #0 (console_owner){-.-.}-{0:0}: check_prev_add kernel/locking/lockdep.c:3165 [inline] check_prevs_add kernel/locking/lockdep.c:3284 [inline] validate_chain kernel/locking/lockdep.c:3908 [inline] __lock_acquire+0x1669/0x2890 kernel/locking/lockdep.c:5237 lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x179/0x330 kernel/locking/lockdep.c:5825 console_lock_spinning_enable+0x72/0x80 kernel/printk/printk.c:1900 console_emit_next_record kernel/printk/printk.c:3123 [inline] console_flush_one_record+0x73f/0xc60 kernel/printk/printk.c:3215 console_flush_all kernel/printk/printk.c:3289 [inline] __console_flush_and_unlock kernel/printk/printk.c:3319 [inline] console_unlock+0xef/0x240 kernel/printk/printk.c:3359 vprintk_emit+0x407/0x6b0 kernel/printk/printk.c:2426 _printk+0xc7/0x100 kernel/printk/printk.c:2451 fail_dump lib/fault-inject.c:66 [inline] should_fail_ex+0x4e7/0x640 lib/fault-inject.c:174 __copy_to_user_inatomic include/linux/uaccess.h:141 [inline] copy_to_user_nofault+0xac/0x1c0 mm/maccess.c:155 ____bpf_probe_write_user kernel/trace/bpf_trace.c:347 [inline] bpf_probe_write_user+0xaf/0xf0 kernel/trace/bpf_trace.c:325 bpf_prog_8f5dadf009f59a0a+0x44/0x4c bpf_dispatcher_nop_func include/linux/bpf.h:1378 [inline] __bpf_prog_run include/linux/filter.h:723 [inline] bpf_prog_run include/linux/filter.h:730 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2075 [inline] bpf_trace_run4+0x252/0x5e0 kernel/trace/bpf_trace.c:2118 __bpf_trace_sched_switch+0x145/0x190 include/trace/events/sched.h:220 __traceiter_sched_switch+0x6f/0xc0 include/trace/events/sched.h:220 __do_trace_sched_switch include/trace/events/sched.h:220 [inline] trace_sched_switch include/trace/events/sched.h:220 [inline] __schedule+0x1a41/0x6150 kernel/sched/core.c:6860 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6960 schedule_hrtimeout_range_clock+0x2dc/0x320 kernel/time/sleep_timeout.c:207 poll_schedule_timeout.constprop.0+0xc4/0x1c0 fs/select.c:241 do_select+0x1338/0x17e0 fs/select.c:603 compat_core_sys_select+0x685/0x880 fs/select.c:1233 do_compat_pselect fs/select.c:1334 [inline] __do_compat_sys_pselect6_time32 fs/select.c:1382 [inline] __se_compat_sys_pselect6_time32 fs/select.c:1373 [inline] __ia32_compat_sys_pselect6_time32+0x2d1/0x390 fs/select.c:1373 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0xe8/0x680 arch/x86/entry/syscall_32.c:307 do_fast_syscall_32+0x32/0x80 arch/x86/entry/syscall_32.c:332 entry_SYSENTER_compat_after_hwframe+0x84/0x8e 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.3.2087/13644: #0: ffff88802b23add8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:647 [inline] #0: ffff88802b23add8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x7e/0x130 kernel/sched/core.c:632 #1: ffffffff8e3c9520 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #1: ffffffff8e3c9520 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #1: ffffffff8e3c9520 (rcu_read_lock){....}-{1:3}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2074 [inline] #1: ffffffff8e3c9520 (rcu_read_lock){....}-{1:3}, at: bpf_trace_run4+0x1d5/0x5e0 kernel/trace/bpf_trace.c:2118 #2: ffffffff8e3b6f00 (console_lock){+.+.}-{0:0}, at: _printk+0xc7/0x100 kernel/printk/printk.c:2451 #3: ffffffff8e3b6f78 (console_srcu){....}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:336 [inline] #3: ffffffff8e3b6f78 (console_srcu){....}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:409 [inline] #3: ffffffff8e3b6f78 (console_srcu){....}-{0:0}, at: console_srcu_read_lock kernel/printk/printk.c:289 [inline] #3: ffffffff8e3b6f78 (console_srcu){....}-{0:0}, at: console_flush_one_record+0x103/0xc60 kernel/printk/printk.c:3192 stack backtrace: CPU: 0 UID: 0 PID: 13644 Comm: syz.3.2087 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_circular_bug+0x275/0x340 kernel/locking/lockdep.c:2043 check_noncircular+0x146/0x160 kernel/locking/lockdep.c:2175 check_prev_add kernel/locking/lockdep.c:3165 [inline] check_prevs_add kernel/locking/lockdep.c:3284 [inline] validate_chain kernel/locking/lockdep.c:3908 [inline] __lock_acquire+0x1669/0x2890 kernel/locking/lockdep.c:5237 lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x179/0x330 kernel/locking/lockdep.c:5825 console_lock_spinning_enable+0x72/0x80 kernel/printk/printk.c:1900 console_emit_next_record kernel/printk/printk.c:3123 [inline] console_flush_one_record+0x73f/0xc60 kernel/printk/printk.c:3215 console_flush_all kernel/printk/printk.c:3289 [inline] __console_flush_and_unlock kernel/printk/printk.c:3319 [inline] console_unlock+0xef/0x240 kernel/printk/printk.c:3359 vprintk_emit+0x407/0x6b0 kernel/printk/printk.c:2426 _printk+0xc7/0x100 kernel/printk/printk.c:2451 fail_dump lib/fault-inject.c:66 [inline] should_fail_ex+0x4e7/0x640 lib/fault-inject.c:174 __copy_to_user_inatomic include/linux/uaccess.h:141 [inline] copy_to_user_nofault+0xac/0x1c0 mm/maccess.c:155 ____bpf_probe_write_user kernel/trace/bpf_trace.c:347 [inline] bpf_probe_write_user+0xaf/0xf0 kernel/trace/bpf_trace.c:325 bpf_prog_8f5dadf009f59a0a+0x44/0x4c bpf_dispatcher_nop_func include/linux/bpf.h:1378 [inline] __bpf_prog_run include/linux/filter.h:723 [inline] bpf_prog_run include/linux/filter.h:730 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2075 [inline] bpf_trace_run4+0x252/0x5e0 kernel/trace/bpf_trace.c:2118 __bpf_trace_sched_switch+0x145/0x190 include/trace/events/sched.h:220 __traceiter_sched_switch+0x6f/0xc0 include/trace/events/sched.h:220 __do_trace_sched_switch include/trace/events/sched.h:220 [inline] trace_sched_switch include/trace/events/sched.h:220 [inline] __schedule+0x1a41/0x6150 kernel/sched/core.c:6860 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6960 schedule_hrtimeout_range_clock+0x2dc/0x320 kernel/time/sleep_timeout.c:207 poll_schedule_timeout.constprop.0+0xc4/0x1c0 fs/select.c:241 do_select+0x1338/0x17e0 fs/select.c:603 compat_core_sys_select+0x685/0x880 fs/select.c:1233 do_compat_pselect fs/select.c:1334 [inline] __do_compat_sys_pselect6_time32 fs/select.c:1382 [inline] __se_compat_sys_pselect6_time32 fs/select.c:1373 [inline] __ia32_compat_sys_pselect6_time32+0x2d1/0x390 fs/select.c:1373 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0xe8/0x680 arch/x86/entry/syscall_32.c:307 do_fast_syscall_32+0x32/0x80 arch/x86/entry/syscall_32.c:332 entry_SYSENTER_compat_after_hwframe+0x84/0x8e RIP: 0023:0xf706d579 Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00 RSP: 002b:00000000f545d55c EFLAGS: 00000296 ORIG_RAX: 0000000000000134 RAX: ffffffffffffffda RBX: 0000000000000040 RCX: 00000000800000c0 RDX: 0000000000000000 RSI: 0000000080000100 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 CPU: 0 UID: 0 PID: 13644 Comm: syz.3.2087 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 fail_dump lib/fault-inject.c:73 [inline] should_fail_ex+0x512/0x640 lib/fault-inject.c:174 __copy_to_user_inatomic include/linux/uaccess.h:141 [inline] copy_to_user_nofault+0xac/0x1c0 mm/maccess.c:155 ____bpf_probe_write_user kernel/trace/bpf_trace.c:347 [inline] bpf_probe_write_user+0xaf/0xf0 kernel/trace/bpf_trace.c:325 bpf_prog_8f5dadf009f59a0a+0x44/0x4c bpf_dispatcher_nop_func include/linux/bpf.h:1378 [inline] __bpf_prog_run include/linux/filter.h:723 [inline] bpf_prog_run include/linux/filter.h:730 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2075 [inline] bpf_trace_run4+0x252/0x5e0 kernel/trace/bpf_trace.c:2118 __bpf_trace_sched_switch+0x145/0x190 include/trace/events/sched.h:220 __traceiter_sched_switch+0x6f/0xc0 include/trace/events/sched.h:220 __do_trace_sched_switch include/trace/events/sched.h:220 [inline] trace_sched_switch include/trace/events/sched.h:220 [inline] __schedule+0x1a41/0x6150 kernel/sched/core.c:6860 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6960 schedule_hrtimeout_range_clock+0x2dc/0x320 kernel/time/sleep_timeout.c:207 poll_schedule_timeout.constprop.0+0xc4/0x1c0 fs/select.c:241 do_select+0x1338/0x17e0 fs/select.c:603 compat_core_sys_select+0x685/0x880 fs/select.c:1233 do_compat_pselect fs/select.c:1334 [inline] __do_compat_sys_pselect6_time32 fs/select.c:1382 [inline] __se_compat_sys_pselect6_time32 fs/select.c:1373 [inline] __ia32_compat_sys_pselect6_time32+0x2d1/0x390 fs/select.c:1373 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0xe8/0x680 arch/x86/entry/syscall_32.c:307 do_fast_syscall_32+0x32/0x80 arch/x86/entry/syscall_32.c:332 entry_SYSENTER_compat_after_hwframe+0x84/0x8e RIP: 0023:0xf706d579 Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00 RSP: 002b:00000000f545d55c EFLAGS: 00000296 ORIG_RAX: 0000000000000134 RAX: ffffffffffffffda RBX: 0000000000000040 RCX: 00000000800000c0 RDX: 0000000000000000 RSI: 0000000080000100 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 ---------------- Code disassembly (best guess), 2 bytes skipped: 0: 10 06 adc %al,(%rsi) 2: 03 74 b4 01 add 0x1(%rsp,%rsi,4),%esi 6: 10 07 adc %al,(%rdi) 8: 03 74 b0 01 add 0x1(%rax,%rsi,4),%esi c: 10 08 adc %cl,(%rax) e: 03 74 d8 01 add 0x1(%rax,%rbx,8),%esi 1e: 00 51 52 add %dl,0x52(%rcx) 21: 55 push %rbp 22: 89 e5 mov %esp,%ebp 24: 0f 34 sysenter 26: cd 80 int $0x80 * 28: 5d pop %rbp <-- trapping instruction 29: 5a pop %rdx 2a: 59 pop %rcx 2b: c3 ret 2c: 90 nop 2d: 90 nop 2e: 90 nop 2f: 90 nop 30: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi 37: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi