loop1: detected capacity change from 0 to 32768 FAULT_INJECTION: forcing a failure. name fail_usercopy, interval 1, probability 0, space 0, times 1 ====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.1.354/5990 is trying to acquire lock: ffffffff8c91f2e0 (console_owner){-.-.}-{0:0}, at: console_lock_spinning_enable kernel/printk/printk.c:1818 [inline] ffffffff8c91f2e0 (console_owner){-.-.}-{0:0}, at: console_emit_next_record+0x82d/0xc90 kernel/printk/printk.c:2774 but task is already holding lock: ffff8880b8e3aad8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xa5/0x140 kernel/sched/core.c:545 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+0x2e/0x40 kernel/locking/spinlock.c:378 raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:537 raw_spin_rq_lock kernel/sched/sched.h:1355 [inline] rq_lock kernel/sched/sched.h:1645 [inline] task_fork_fair+0x5c/0x350 kernel/sched/fair.c:11901 sched_cgroup_fork+0x32c/0x3c0 kernel/sched/core.c:4685 copy_process+0x24b8/0x4020 kernel/fork.c:2459 kernel_clone+0x225/0x8b0 kernel/fork.c:2757 user_mode_thread+0xda/0x130 kernel/fork.c:2833 rest_init+0x23/0x300 init/main.c:710 start_kernel+0x0/0x539 init/main.c:905 start_kernel+0x490/0x539 init/main.c:1152 secondary_startup_64_no_verify+0xcf/0xdb -> #3 (&p->pi_lock){-.-.}-{2:2}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xa4/0xf0 kernel/locking/spinlock.c:162 try_to_wake_up+0x5c/0x1080 kernel/sched/core.c:4111 __wake_up_common+0x2a4/0x4e0 kernel/sched/wait.c:107 __wake_up_common_lock kernel/sched/wait.c:138 [inline] __wake_up+0x10e/0x190 kernel/sched/wait.c:160 pty_close+0x265/0x440 drivers/tty/pty.c:68 tty_release+0x383/0x1600 drivers/tty/tty_io.c:1753 __fput+0x22c/0x920 fs/file_table.c:320 task_work_run+0x1ca/0x250 kernel/task_work.c:203 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:177 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 -> #2 (&tty->write_wait){-...}-{2:2}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xa4/0xf0 kernel/locking/spinlock.c:162 __wake_up_common_lock kernel/sched/wait.c:137 [inline] __wake_up+0xf4/0x190 kernel/sched/wait.c:160 tty_port_default_wakeup+0x9e/0xf0 drivers/tty/tty_port.c:71 serial8250_tx_chars+0x629/0x830 drivers/tty/serial/8250/8250_port.c:1854 serial8250_handle_irq+0x516/0x6d0 drivers/tty/serial/8250/8250_port.c:1961 serial8250_default_handle_irq+0xb4/0x1a0 drivers/tty/serial/8250/8250_port.c:1981 serial8250_interrupt+0x9b/0x1c0 drivers/tty/serial/8250/8250_core.c:126 __handle_irq_event_percpu+0x298/0xa30 kernel/irq/handle.c:158 handle_irq_event_percpu kernel/irq/handle.c:193 [inline] handle_irq_event+0x87/0x1e0 kernel/irq/handle.c:210 handle_edge_irq+0x243/0xb20 kernel/irq/chip.c:819 generic_handle_irq_desc include/linux/irqdesc.h:158 [inline] handle_irq arch/x86/kernel/irq.c:233 [inline] __common_interrupt+0xd7/0x1e0 arch/x86/kernel/irq.c:252 common_interrupt+0xb0/0xd0 arch/x86/kernel/irq.c:242 asm_common_interrupt+0x22/0x40 arch/x86/include/asm/idtentry.h:682 native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline] arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline] default_idle+0xb/0x10 arch/x86/kernel/process.c:741 default_idle_call+0x84/0xc0 kernel/sched/idle.c:109 cpuidle_idle_call kernel/sched/idle.c:191 [inline] do_idle+0x1fc/0x570 kernel/sched/idle.c:303 cpu_startup_entry+0x3f/0x60 kernel/sched/idle.c:401 rest_init+0x2dc/0x300 init/main.c:745 start_kernel+0x0/0x539 init/main.c:905 start_kernel+0x490/0x539 init/main.c:1152 secondary_startup_64_no_verify+0xcf/0xdb -> #1 (&port_lock_key){-.-.}-{2:2}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xa4/0xf0 kernel/locking/spinlock.c:162 serial8250_console_write+0x169/0x17a0 drivers/tty/serial/8250/8250_port.c:3432 call_console_driver kernel/printk/printk.c:1977 [inline] console_emit_next_record+0x947/0xc90 kernel/printk/printk.c:2777 console_flush_all kernel/printk/printk.c:-1 [inline] console_unlock+0x223/0x630 kernel/printk/printk.c:2906 vprintk_emit+0x489/0x680 kernel/printk/printk.c:2303 _printk+0xcc/0x110 kernel/printk/printk.c:2328 register_console+0x6c6/0x9c0 kernel/printk/printk.c:3269 univ8250_console_init+0x41/0x43 drivers/tty/serial/8250/8250_core.c:687 console_init+0x1bc/0x78e kernel/printk/printk.c:3359 start_kernel+0x303/0x539 init/main.c:1088 secondary_startup_64_no_verify+0xcf/0xdb -> #0 (console_owner){-.-.}-{0:0}: check_prev_add kernel/locking/lockdep.c:3090 [inline] check_prevs_add kernel/locking/lockdep.c:3209 [inline] validate_chain kernel/locking/lockdep.c:3825 [inline] __lock_acquire+0x2cf8/0x7c50 kernel/locking/lockdep.c:5049 lock_acquire+0x1b4/0x490 kernel/locking/lockdep.c:5662 console_lock_spinning_enable kernel/printk/printk.c:1818 [inline] console_emit_next_record+0x84c/0xc90 kernel/printk/printk.c:2774 console_flush_all kernel/printk/printk.c:-1 [inline] console_unlock+0x223/0x630 kernel/printk/printk.c:2906 vprintk_emit+0x489/0x680 kernel/printk/printk.c:2303 _printk+0xcc/0x110 kernel/printk/printk.c:2328 fail_dump lib/fault-inject.c:45 [inline] should_fail_ex+0x37a/0x4d0 lib/fault-inject.c:147 strncpy_from_user+0x32/0x350 lib/strncpy_from_user.c:118 strncpy_from_user_nofault+0x6d/0x140 mm/maccess.c:186 bpf_trace_copy_string kernel/bpf/helpers.c:746 [inline] bpf_bprintf_prepare+0xba0/0x13d0 kernel/bpf/helpers.c:971 ____bpf_trace_printk kernel/trace/bpf_trace.c:384 [inline] bpf_trace_printk+0xd8/0x190 kernel/trace/bpf_trace.c:374 bpf_prog_7c77c7e0f6645ad8+0x35/0x37 bpf_dispatcher_nop_func include/linux/bpf.h:1012 [inline] __bpf_prog_run include/linux/filter.h:603 [inline] bpf_prog_run include/linux/filter.h:610 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2285 [inline] bpf_trace_run2+0x1cd/0x3b0 kernel/trace/bpf_trace.c:2324 trace_contention_begin+0x142/0x190 include/trace/events/lock.h:95 __pv_queued_spin_lock_slowpath+0xdc/0x9c0 kernel/locking/qspinlock.c:405 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:591 [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+0x217/0x280 kernel/locking/spinlock_debug.c:115 raw_spin_rq_lock_nested+0xa5/0x140 kernel/sched/core.c:545 raw_spin_rq_lock kernel/sched/sched.h:1355 [inline] rq_lock kernel/sched/sched.h:1645 [inline] __schedule+0x2ed/0x40b0 kernel/sched/core.c:6477 preempt_schedule_irq+0xb1/0x150 kernel/sched/core.c:6873 irqentry_exit+0x63/0x70 kernel/entry/common.c:439 asm_sysvec_reschedule_ipi+0x16/0x20 arch/x86/include/asm/idtentry.h:696 do_syscall_64+0x50/0xa0 arch/x86/entry/common.c:-1 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 *** 3 locks held by syz.1.354/5990: #0: ffff8880b8e3aad8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xa5/0x140 kernel/sched/core.c:545 #1: ffffffff8c92b120 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #1: ffffffff8c92b120 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #1: ffffffff8c92b120 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2284 [inline] #1: ffffffff8c92b120 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0xda/0x3b0 kernel/trace/bpf_trace.c:2324 #2: ffffffff8c91f3c0 (console_lock){+.+.}-{0:0}, at: _printk+0xcc/0x110 kernel/printk/printk.c:2328 stack backtrace: CPU: 0 PID: 5990 Comm: syz.1.354 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106 check_noncircular+0x274/0x310 kernel/locking/lockdep.c:2170 check_prev_add kernel/locking/lockdep.c:3090 [inline] check_prevs_add kernel/locking/lockdep.c:3209 [inline] validate_chain kernel/locking/lockdep.c:3825 [inline] __lock_acquire+0x2cf8/0x7c50 kernel/locking/lockdep.c:5049 lock_acquire+0x1b4/0x490 kernel/locking/lockdep.c:5662 console_lock_spinning_enable kernel/printk/printk.c:1818 [inline] console_emit_next_record+0x84c/0xc90 kernel/printk/printk.c:2774 console_flush_all kernel/printk/printk.c:-1 [inline] console_unlock+0x223/0x630 kernel/printk/printk.c:2906 vprintk_emit+0x489/0x680 kernel/printk/printk.c:2303 _printk+0xcc/0x110 kernel/printk/printk.c:2328 fail_dump lib/fault-inject.c:45 [inline] should_fail_ex+0x37a/0x4d0 lib/fault-inject.c:147 strncpy_from_user+0x32/0x350 lib/strncpy_from_user.c:118 strncpy_from_user_nofault+0x6d/0x140 mm/maccess.c:186 bpf_trace_copy_string kernel/bpf/helpers.c:746 [inline] bpf_bprintf_prepare+0xba0/0x13d0 kernel/bpf/helpers.c:971 ____bpf_trace_printk kernel/trace/bpf_trace.c:384 [inline] bpf_trace_printk+0xd8/0x190 kernel/trace/bpf_trace.c:374 bpf_prog_7c77c7e0f6645ad8+0x35/0x37 bpf_dispatcher_nop_func include/linux/bpf.h:1012 [inline] __bpf_prog_run include/linux/filter.h:603 [inline] bpf_prog_run include/linux/filter.h:610 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2285 [inline] bpf_trace_run2+0x1cd/0x3b0 kernel/trace/bpf_trace.c:2324 trace_contention_begin+0x142/0x190 include/trace/events/lock.h:95 __pv_queued_spin_lock_slowpath+0xdc/0x9c0 kernel/locking/qspinlock.c:405 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:591 [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+0x217/0x280 kernel/locking/spinlock_debug.c:115 raw_spin_rq_lock_nested+0xa5/0x140 kernel/sched/core.c:545 raw_spin_rq_lock kernel/sched/sched.h:1355 [inline] rq_lock kernel/sched/sched.h:1645 [inline] __schedule+0x2ed/0x40b0 kernel/sched/core.c:6477 preempt_schedule_irq+0xb1/0x150 kernel/sched/core.c:6873 irqentry_exit+0x63/0x70 kernel/entry/common.c:439 asm_sysvec_reschedule_ipi+0x16/0x20 arch/x86/include/asm/idtentry.h:696 RIP: 0010:do_syscall_64+0x50/0xa0 arch/x86/entry/common.c:87 Code: c7 41 81 ff c2 01 00 00 77 33 44 89 ff 81 e7 ff 01 00 00 e8 32 25 f0 f6 41 21 c7 4c 89 f7 44 89 fe e8 24 1e f0 f6 49 89 46 50 <4c> 89 f7 e8 d8 47 00 00 48 8d 65 e8 5b 41 5e 41 5f 5d c3 41 83 ff RSP: 0018:ffffc90003ae7f20 EFLAGS: 00000246 RAX: 0000000000000001 RBX: ffffc90003ae7f20 RCX: ffff888027075940 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000002 RBP: ffffc90003ae7f48 R08: dffffc0000000000 R09: ffffed1004926def R10: ffffed1004926def R11: 1ffff11004926dee R12: 0000000000000000 R13: 0000000000000000 R14: ffffc90003ae7f58 R15: 0000000000000001 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f557958e1ff Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 f9 92 02 00 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 4c 93 02 00 48 RSP: 002b:00007f557a4c5030 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: 0000000000000001 RBX: 0000000000000009 RCX: 00007f557958e1ff RDX: 0000000000000001 RSI: 00007f557a4c5090 RDI: 0000000000000009 RBP: 00007f557a4c5090 R08: 0000000000000000 R09: 00007f557a4c4df7 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000001 R13: 00007f55797e6128 R14: 00007f55797e6090 R15: 00007ffeacb437c8 CPU: 0 PID: 5990 Comm: syz.1.354 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106 fail_dump lib/fault-inject.c:52 [inline] should_fail_ex+0x399/0x4d0 lib/fault-inject.c:147 strncpy_from_user+0x32/0x350 lib/strncpy_from_user.c:118 strncpy_from_user_nofault+0x6d/0x140 mm/maccess.c:186 bpf_trace_copy_string kernel/bpf/helpers.c:746 [inline] bpf_bprintf_prepare+0xba0/0x13d0 kernel/bpf/helpers.c:971 ____bpf_trace_printk kernel/trace/bpf_trace.c:384 [inline] bpf_trace_printk+0xd8/0x190 kernel/trace/bpf_trace.c:374 bpf_prog_7c77c7e0f6645ad8+0x35/0x37 bpf_dispatcher_nop_func include/linux/bpf.h:1012 [inline] __bpf_prog_run include/linux/filter.h:603 [inline] bpf_prog_run include/linux/filter.h:610 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2285 [inline] bpf_trace_run2+0x1cd/0x3b0 kernel/trace/bpf_trace.c:2324 trace_contention_begin+0x142/0x190 include/trace/events/lock.h:95 __pv_queued_spin_lock_slowpath+0xdc/0x9c0 kernel/locking/qspinlock.c:405 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:591 [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+0x217/0x280 kernel/locking/spinlock_debug.c:115 raw_spin_rq_lock_nested+0xa5/0x140 kernel/sched/core.c:545 raw_spin_rq_lock kernel/sched/sched.h:1355 [inline] rq_lock kernel/sched/sched.h:1645 [inline] __schedule+0x2ed/0x40b0 kernel/sched/core.c:6477 preempt_schedule_irq+0xb1/0x150 kernel/sched/core.c:6873 irqentry_exit+0x63/0x70 kernel/entry/common.c:439 asm_sysvec_reschedule_ipi+0x16/0x20 arch/x86/include/asm/idtentry.h:696 RIP: 0010:do_syscall_64+0x50/0xa0 arch/x86/entry/common.c:87 Code: c7 41 81 ff c2 01 00 00 77 33 44 89 ff 81 e7 ff 01 00 00 e8 32 25 f0 f6 41 21 c7 4c 89 f7 44 89 fe e8 24 1e f0 f6 49 89 46 50 <4c> 89 f7 e8 d8 47 00 00 48 8d 65 e8 5b 41 5e 41 5f 5d c3 41 83 ff RSP: 0018:ffffc90003ae7f20 EFLAGS: 00000246 RAX: 0000000000000001 RBX: ffffc90003ae7f20 RCX: ffff888027075940 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000002 RBP: ffffc90003ae7f48 R08: dffffc0000000000 R09: ffffed1004926def R10: ffffed1004926def R11: 1ffff11004926dee R12: 0000000000000000 R13: 0000000000000000 R14: ffffc90003ae7f58 R15: 0000000000000001 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f557958e1ff Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 f9 92 02 00 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 4c 93 02 00 48 RSP: 002b:00007f557a4c5030 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: 0000000000000001 RBX: 0000000000000009 RCX: 00007f557958e1ff RDX: 0000000000000001 RSI: 00007f557a4c5090 RDI: 0000000000000009 RBP: 00007f557a4c5090 R08: 0000000000000000 R09: 00007f557a4c4df7 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000001 R13: 00007f55797e6128 R14: 00007f55797e6090 R15: 00007ffeacb437c8 ---------------- Code disassembly (best guess): 0: c7 41 81 ff c2 01 00 movl $0x1c2ff,-0x7f(%rcx) 7: 00 77 33 add %dh,0x33(%rdi) a: 44 89 ff mov %r15d,%edi d: 81 e7 ff 01 00 00 and $0x1ff,%edi 13: e8 32 25 f0 f6 call 0xf6f0254a 18: 41 21 c7 and %eax,%r15d 1b: 4c 89 f7 mov %r14,%rdi 1e: 44 89 fe mov %r15d,%esi 21: e8 24 1e f0 f6 call 0xf6f01e4a 26: 49 89 46 50 mov %rax,0x50(%r14) * 2a: 4c 89 f7 mov %r14,%rdi <-- trapping instruction 2d: e8 d8 47 00 00 call 0x480a 32: 48 8d 65 e8 lea -0x18(%rbp),%rsp 36: 5b pop %rbx 37: 41 5e pop %r14 39: 41 5f pop %r15 3b: 5d pop %rbp 3c: c3 ret 3d: 41 rex.B 3e: 83 .byte 0x83 3f: ff .byte 0xff