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.5.3057/17701 is trying to acquire lock: ffffffff8df35860 (console_owner){-.-.}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:336 [inline] ffffffff8df35860 (console_owner){-.-.}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:409 [inline] ffffffff8df35860 (console_owner){-.-.}-{0:0}, at: console_srcu_read_lock kernel/printk/printk.c:289 [inline] ffffffff8df35860 (console_owner){-.-.}-{0:0}, at: console_flush_one_record kernel/printk/printk.c:3192 [inline] ffffffff8df35860 (console_owner){-.-.}-{0:0}, at: console_flush_all+0x131/0xb60 kernel/printk/printk.c:3289 but task is already holding lock: ffff8880b863a918 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xad/0x140 kernel/sched/core.c:647 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+0x2a/0x140 kernel/sched/core.c:639 raw_spin_rq_lock kernel/sched/sched.h:1558 [inline] task_rq_lock+0xbc/0x470 kernel/sched/core.c:739 cgroup_move_task+0x92/0x2a0 kernel/sched/psi.c:1170 css_set_move_task+0x658/0x9e0 kernel/cgroup/cgroup.c:951 cgroup_post_fork+0x1ef/0x7a0 kernel/cgroup/cgroup.c:6913 copy_process+0x3614/0x3950 kernel/fork.c:2465 kernel_clone+0x21e/0x820 kernel/fork.c:2651 user_mode_thread+0xdd/0x140 kernel/fork.c:2727 rest_init+0x23/0x300 init/main.c:722 start_kernel+0x3a7/0x400 init/main.c:1206 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310 x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:291 common_startup_64+0x13e/0x147 -> #3 (&p->pi_lock){-.-.}-{2:2}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xa7/0xf0 kernel/locking/spinlock.c:162 class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:557 [inline] try_to_wake_up+0x67/0x12b0 kernel/sched/core.c:4106 __wake_up_common kernel/sched/wait.c:108 [inline] __wake_up_common_lock+0x137/0x1f0 kernel/sched/wait.c:125 tty_port_default_wakeup+0xfb/0x170 drivers/tty/tty_port.c:67 serial8250_tx_chars+0x72e/0x970 drivers/tty/serial/8250/8250_port.c:1719 serial8250_handle_irq+0x633/0xbb0 drivers/tty/serial/8250/8250_port.c:1827 serial8250_default_handle_irq+0xbf/0x200 drivers/tty/serial/8250/8250_port.c:1846 serial8250_interrupt+0x8d/0x180 drivers/tty/serial/8250/8250_core.c:86 __handle_irq_event_percpu+0x285/0xa60 kernel/irq/handle.c:211 handle_irq_event_percpu kernel/irq/handle.c:248 [inline] handle_irq_event+0x8b/0x1e0 kernel/irq/handle.c:265 handle_edge_irq+0x23b/0xa10 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:-1 [inline] __common_interrupt+0x141/0x1f0 arch/x86/kernel/irq.c:326 common_interrupt+0xb6/0xe0 arch/x86/kernel/irq.c:319 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:688 native_irq_enable arch/x86/include/asm/irqflags.h:42 [inline] arch_local_irq_enable arch/x86/include/asm/irqflags.h:119 [inline] raw_spin_rq_unlock_irq kernel/sched/sched.h:1570 [inline] finish_lock_switch kernel/sched/core.c:4995 [inline] finish_task_switch+0x242/0x940 kernel/sched/core.c:5112 context_switch kernel/sched/core.c:5259 [inline] __schedule+0x14c4/0x5000 kernel/sched/core.c:6863 schedule_idle+0x52/0x90 kernel/sched/core.c:6986 do_idle+0x4b3/0x520 kernel/sched/idle.c:360 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:430 start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:312 common_startup_64+0x13e/0x147 -> #2 (&tty->write_wait){-...}-{3:3}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xa7/0xf0 kernel/locking/spinlock.c:162 __wake_up_common_lock+0x2f/0x1f0 kernel/sched/wait.c:124 tty_port_default_wakeup+0xfb/0x170 drivers/tty/tty_port.c:67 serial8250_tx_chars+0x72e/0x970 drivers/tty/serial/8250/8250_port.c:1719 serial8250_handle_irq+0x633/0xbb0 drivers/tty/serial/8250/8250_port.c:1827 serial8250_default_handle_irq+0xbf/0x200 drivers/tty/serial/8250/8250_port.c:1846 serial8250_interrupt+0x8d/0x180 drivers/tty/serial/8250/8250_core.c:86 __handle_irq_event_percpu+0x285/0xa60 kernel/irq/handle.c:211 handle_irq_event_percpu kernel/irq/handle.c:248 [inline] handle_irq_event+0x8b/0x1e0 kernel/irq/handle.c:265 handle_edge_irq+0x23b/0xa10 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:-1 [inline] __common_interrupt+0x141/0x1f0 arch/x86/kernel/irq.c:326 common_interrupt+0xb6/0xe0 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+0x13/0x20 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+0x73/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:191 [inline] do_idle+0x1ea/0x520 kernel/sched/idle.c:332 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:430 start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:312 common_startup_64+0x13e/0x147 -> #1 (&port_lock_key){-.-.}-{3:3}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xa7/0xf0 kernel/locking/spinlock.c:162 uart_port_lock_irqsave include/linux/serial_core.h:717 [inline] serial8250_console_write+0x17e/0x1ba0 drivers/tty/serial/8250/8250_port.c:3301 console_emit_next_record kernel/printk/printk.c:3129 [inline] console_flush_one_record kernel/printk/printk.c:3215 [inline] console_flush_all+0x745/0xb60 kernel/printk/printk.c:3289 __console_flush_and_unlock kernel/printk/printk.c:3319 [inline] console_unlock+0xbb/0x190 kernel/printk/printk.c:3359 vprintk_emit+0x4f8/0x5f0 kernel/printk/printk.c:2426 _printk+0xcf/0x120 kernel/printk/printk.c:2451 register_console+0xa8b/0xf90 kernel/printk/printk.c:4170 univ8250_console_init+0x3a/0x70 drivers/tty/serial/8250/8250_core.c:515 console_init+0xfc/0x3f0 kernel/printk/printk.c:4369 start_kernel+0x24d/0x400 init/main.c:1143 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310 x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:291 common_startup_64+0x13e/0x147 -> #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+0x15a6/0x2cf0 kernel/locking/lockdep.c:5237 lock_acquire+0x117/0x340 kernel/locking/lockdep.c:5868 console_lock_spinning_enable kernel/printk/printk.c:1900 [inline] console_emit_next_record kernel/printk/printk.c:3123 [inline] console_flush_one_record kernel/printk/printk.c:3215 [inline] console_flush_all+0x6ee/0xb60 kernel/printk/printk.c:3289 __console_flush_and_unlock kernel/printk/printk.c:3319 [inline] console_unlock+0xbb/0x190 kernel/printk/printk.c:3359 vprintk_emit+0x4f8/0x5f0 kernel/printk/printk.c:2426 _printk+0xcf/0x120 kernel/printk/printk.c:2451 fail_dump lib/fault-inject.c:66 [inline] should_fail_ex+0x3f5/0x560 lib/fault-inject.c:174 strncpy_from_user+0x36/0x2c0 lib/strncpy_from_user.c:118 strncpy_from_user_nofault+0x72/0x150 mm/maccess.c:192 bpf_trace_copy_string kernel/bpf/helpers.c:755 [inline] bpf_bprintf_prepare+0xbbc/0x13d0 kernel/bpf/helpers.c:976 ____bpf_trace_printk kernel/trace/bpf_trace.c:372 [inline] bpf_trace_printk+0xdb/0x190 kernel/trace/bpf_trace.c:362 bpf_prog_930ede9872f2967c+0x3e/0x44 bpf_dispatcher_nop_func include/linux/bpf.h:1376 [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_run2+0x284/0x4c0 kernel/trace/bpf_trace.c:2116 __bpf_trace_contention_begin+0xdc/0x130 include/trace/events/lock.h:95 __do_trace_contention_begin include/trace/events/lock.h:95 [inline] trace_contention_begin+0xfe/0x120 include/trace/events/lock.h:95 __pv_queued_spin_lock_slowpath+0xf0/0xb60 kernel/locking/qspinlock.c:219 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:557 [inline] queued_spin_lock_slowpath+0x43/0x50 arch/x86/include/asm/qspinlock.h:51 queued_spin_lock include/asm-generic/qspinlock.h:114 [inline] do_raw_spin_lock+0x21f/0x290 kernel/locking/spinlock_debug.c:116 raw_spin_rq_lock_nested+0xad/0x140 kernel/sched/core.c:647 raw_spin_rq_lock kernel/sched/sched.h:1558 [inline] rq_lock kernel/sched/sched.h:1885 [inline] __schedule+0x3e5/0x5000 kernel/sched/core.c:6768 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0x165/0x360 kernel/sched/core.c:6960 __exit_to_user_mode_loop kernel/entry/common.c:32 [inline] exit_to_user_mode_loop kernel/entry/common.c:75 [inline] __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] irqentry_exit_to_user_mode_prepare include/linux/irq-entry-common.h:270 [inline] irqentry_exit_to_user_mode include/linux/irq-entry-common.h:339 [inline] irqentry_exit+0x156/0x660 kernel/entry/common.c:196 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 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.5.3057/17701: #0: ffff8880b863a918 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xad/0x140 kernel/sched/core.c:647 #1: ffffffff8df419e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #1: ffffffff8df419e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #1: ffffffff8df419e0 (rcu_read_lock){....}-{1:3}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2074 [inline] #1: ffffffff8df419e0 (rcu_read_lock){....}-{1:3}, at: bpf_trace_run2+0x186/0x4c0 kernel/trace/bpf_trace.c:2116 #2: ffffffff8df358c0 (console_lock){+.+.}-{0:0}, at: _printk+0xcf/0x120 kernel/printk/printk.c:2451 #3: ffffffff8de1d178 (console_srcu){....}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:336 [inline] #3: ffffffff8de1d178 (console_srcu){....}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:409 [inline] #3: ffffffff8de1d178 (console_srcu){....}-{0:0}, at: console_srcu_read_lock kernel/printk/printk.c:289 [inline] #3: ffffffff8de1d178 (console_srcu){....}-{0:0}, at: console_flush_one_record kernel/printk/printk.c:3192 [inline] #3: ffffffff8de1d178 (console_srcu){....}-{0:0}, at: console_flush_all+0x131/0xb60 kernel/printk/printk.c:3289 stack backtrace: CPU: 0 UID: 0 PID: 17701 Comm: syz.5.3057 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_circular_bug+0x2e2/0x300 kernel/locking/lockdep.c:2043 check_noncircular+0x12e/0x150 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+0x15a6/0x2cf0 kernel/locking/lockdep.c:5237 lock_acquire+0x117/0x340 kernel/locking/lockdep.c:5868 console_lock_spinning_enable kernel/printk/printk.c:1900 [inline] console_emit_next_record kernel/printk/printk.c:3123 [inline] console_flush_one_record kernel/printk/printk.c:3215 [inline] console_flush_all+0x6ee/0xb60 kernel/printk/printk.c:3289 __console_flush_and_unlock kernel/printk/printk.c:3319 [inline] console_unlock+0xbb/0x190 kernel/printk/printk.c:3359 vprintk_emit+0x4f8/0x5f0 kernel/printk/printk.c:2426 _printk+0xcf/0x120 kernel/printk/printk.c:2451 fail_dump lib/fault-inject.c:66 [inline] should_fail_ex+0x3f5/0x560 lib/fault-inject.c:174 strncpy_from_user+0x36/0x2c0 lib/strncpy_from_user.c:118 strncpy_from_user_nofault+0x72/0x150 mm/maccess.c:192 bpf_trace_copy_string kernel/bpf/helpers.c:755 [inline] bpf_bprintf_prepare+0xbbc/0x13d0 kernel/bpf/helpers.c:976 ____bpf_trace_printk kernel/trace/bpf_trace.c:372 [inline] bpf_trace_printk+0xdb/0x190 kernel/trace/bpf_trace.c:362 bpf_prog_930ede9872f2967c+0x3e/0x44 bpf_dispatcher_nop_func include/linux/bpf.h:1376 [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_run2+0x284/0x4c0 kernel/trace/bpf_trace.c:2116 __bpf_trace_contention_begin+0xdc/0x130 include/trace/events/lock.h:95 __do_trace_contention_begin include/trace/events/lock.h:95 [inline] trace_contention_begin+0xfe/0x120 include/trace/events/lock.h:95 __pv_queued_spin_lock_slowpath+0xf0/0xb60 kernel/locking/qspinlock.c:219 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:557 [inline] queued_spin_lock_slowpath+0x43/0x50 arch/x86/include/asm/qspinlock.h:51 queued_spin_lock include/asm-generic/qspinlock.h:114 [inline] do_raw_spin_lock+0x21f/0x290 kernel/locking/spinlock_debug.c:116 raw_spin_rq_lock_nested+0xad/0x140 kernel/sched/core.c:647 raw_spin_rq_lock kernel/sched/sched.h:1558 [inline] rq_lock kernel/sched/sched.h:1885 [inline] __schedule+0x3e5/0x5000 kernel/sched/core.c:6768 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0x165/0x360 kernel/sched/core.c:6960 __exit_to_user_mode_loop kernel/entry/common.c:32 [inline] exit_to_user_mode_loop kernel/entry/common.c:75 [inline] __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] irqentry_exit_to_user_mode_prepare include/linux/irq-entry-common.h:270 [inline] irqentry_exit_to_user_mode include/linux/irq-entry-common.h:339 [inline] irqentry_exit+0x156/0x660 kernel/entry/common.c:196 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0033:0x7fb93b53ab02 Code: d2 0f 85 11 06 00 00 45 85 e4 0f 88 b8 00 00 00 4c 8b a4 24 90 00 00 00 41 80 3c 24 00 0f 84 a5 00 00 00 48 8b 05 b6 2e de 00 <48> 89 44 24 78 48 85 c0 0f 85 40 1a 00 00 48 83 3d 90 2e de 00 00 RSP: 002b:00007fb9397d46b0 EFLAGS: 00000202 RAX: 0000000000000000 RBX: 00007fb9397d4c10 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 00007fb93b614c04 RDI: 00007fb9397d4eb9 RBP: 0000000000000009 R08: 0000000000000000 R09: 0000000000000000 R10: 00002000000000c0 R11: 0000000000000004 R12: 00007fb93b614c0d R13: 00007fb9397d4d90 R14: 0000000000000000 R15: 00007fb9397d4c10 CPU: 0 UID: 0 PID: 17701 Comm: syz.5.3057 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 fail_dump lib/fault-inject.c:73 [inline] should_fail_ex+0x414/0x560 lib/fault-inject.c:174 strncpy_from_user+0x36/0x2c0 lib/strncpy_from_user.c:118 strncpy_from_user_nofault+0x72/0x150 mm/maccess.c:192 bpf_trace_copy_string kernel/bpf/helpers.c:755 [inline] bpf_bprintf_prepare+0xbbc/0x13d0 kernel/bpf/helpers.c:976 ____bpf_trace_printk kernel/trace/bpf_trace.c:372 [inline] bpf_trace_printk+0xdb/0x190 kernel/trace/bpf_trace.c:362 bpf_prog_930ede9872f2967c+0x3e/0x44 bpf_dispatcher_nop_func include/linux/bpf.h:1376 [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_run2+0x284/0x4c0 kernel/trace/bpf_trace.c:2116 __bpf_trace_contention_begin+0xdc/0x130 include/trace/events/lock.h:95 __do_trace_contention_begin include/trace/events/lock.h:95 [inline] trace_contention_begin+0xfe/0x120 include/trace/events/lock.h:95 __pv_queued_spin_lock_slowpath+0xf0/0xb60 kernel/locking/qspinlock.c:219 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:557 [inline] queued_spin_lock_slowpath+0x43/0x50 arch/x86/include/asm/qspinlock.h:51 queued_spin_lock include/asm-generic/qspinlock.h:114 [inline] do_raw_spin_lock+0x21f/0x290 kernel/locking/spinlock_debug.c:116 raw_spin_rq_lock_nested+0xad/0x140 kernel/sched/core.c:647 raw_spin_rq_lock kernel/sched/sched.h:1558 [inline] rq_lock kernel/sched/sched.h:1885 [inline] __schedule+0x3e5/0x5000 kernel/sched/core.c:6768 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0x165/0x360 kernel/sched/core.c:6960 __exit_to_user_mode_loop kernel/entry/common.c:32 [inline] exit_to_user_mode_loop kernel/entry/common.c:75 [inline] __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] irqentry_exit_to_user_mode_prepare include/linux/irq-entry-common.h:270 [inline] irqentry_exit_to_user_mode include/linux/irq-entry-common.h:339 [inline] irqentry_exit+0x156/0x660 kernel/entry/common.c:196 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0033:0x7fb93b53ab02 Code: d2 0f 85 11 06 00 00 45 85 e4 0f 88 b8 00 00 00 4c 8b a4 24 90 00 00 00 41 80 3c 24 00 0f 84 a5 00 00 00 48 8b 05 b6 2e de 00 <48> 89 44 24 78 48 85 c0 0f 85 40 1a 00 00 48 83 3d 90 2e de 00 00 RSP: 002b:00007fb9397d46b0 EFLAGS: 00000202 RAX: 0000000000000000 RBX: 00007fb9397d4c10 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 00007fb93b614c04 RDI: 00007fb9397d4eb9 RBP: 0000000000000009 R08: 0000000000000000 R09: 0000000000000000 R10: 00002000000000c0 R11: 0000000000000004 R12: 00007fb93b614c0d R13: 00007fb9397d4d90 R14: 0000000000000000 R15: 00007fb9397d4c10 loop5: detected capacity change from 0 to 2048 UDF-fs: INFO Mounting volume 'LiuxUDF', timestamp 2022/11/22 14:59 (1000)