FAULT_INJECTION: forcing a failure. name fail_usercopy, interval 1, probability 0, space 0, times 0 ====================================================== WARNING: possible circular locking dependency detected 6.15.0-rc2-syzkaller #0 Not tainted ------------------------------------------------------ syz.3.263/6863 is trying to acquire lock: ffffffff8ec19ac0 (console_owner){-.-.}-{0:0}, at: console_trylock_spinning kernel/printk/printk.c:2048 [inline] ffffffff8ec19ac0 (console_owner){-.-.}-{0:0}, at: vprintk_emit+0x552/0xa40 kernel/printk/printk.c:2449 but task is already holding lock: ffff8880b8639998 (&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:6715 copy_process+0x39b5/0x3d10 kernel/fork.c:2658 kernel_clone+0x227/0x880 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+0xb4/0xd0 arch/x86/kernel/irq.c:285 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:693 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+0xb4/0xd0 arch/x86/kernel/irq.c:285 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:693 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] _raw_spin_unlock_irqrestore+0xd9/0x140 kernel/locking/spinlock.c:194 spin_unlock_irqrestore include/linux/spinlock.h:406 [inline] uart_port_unlock_irqrestore include/linux/serial_core.h:786 [inline] uart_write+0x3e4/0xa40 drivers/tty/serial/serial_core.c:636 process_output_block drivers/tty/n_tty.c:561 [inline] n_tty_write+0xd81/0x1270 drivers/tty/n_tty.c:2377 iterate_tty_write drivers/tty/tty_io.c:1015 [inline] file_tty_write+0x543/0x9d0 drivers/tty/tty_io.c:1090 new_sync_write fs/read_write.c:591 [inline] vfs_write+0x70f/0xd10 fs/read_write.c:684 ksys_write+0x19d/0x2d0 fs/read_write.c:736 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #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 __copy_to_user_inatomic include/linux/uaccess.h:132 [inline] copy_to_user_nofault+0x84/0x150 mm/maccess.c:156 bpf_prog_6303d92f98284ad8+0x44/0x48 bpf_dispatcher_nop_func include/linux/bpf.h:1316 [inline] __bpf_prog_run include/linux/filter.h:718 [inline] bpf_prog_run include/linux/filter.h:725 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2363 [inline] bpf_trace_run4+0x336/0x5a0 kernel/trace/bpf_trace.c:2406 __bpf_trace_sched_switch+0x296/0x3d0 include/trace/events/sched.h:220 __traceiter_sched_switch+0x98/0xd0 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+0x28bb/0x51f0 kernel/sched/core.c:6764 preempt_schedule_common+0x84/0xd0 kernel/sched/core.c:6947 preempt_schedule+0xe4/0xf0 kernel/sched/core.c:6971 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline] _raw_spin_unlock+0x3e/0x50 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:391 [inline] ilookup5_nowait fs/inode.c:1582 [inline] ilookup5+0xb0/0x160 fs/inode.c:1610 fuse_ilookup+0x164/0x250 fs/fuse/inode.c:542 fuse_reverse_inval_entry+0x33/0x720 fs/fuse/dir.c:1395 fuse_notify fs/fuse/dev.c:-1 [inline] fuse_dev_do_write+0x4af9/0x5900 fs/fuse/dev.c:2132 fuse_dev_write+0x179/0x220 fs/fuse/dev.c:2216 new_sync_write fs/read_write.c:591 [inline] vfs_write+0x70f/0xd10 fs/read_write.c:684 ksys_write+0x19d/0x2d0 fs/read_write.c:736 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf3/0x230 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.3.263/6863: #0: ffff8880227f9350 (&fc->killsb){++++}-{4:4}, at: fuse_notify_delete fs/fuse/dev.c:1729 [inline] #0: ffff8880227f9350 (&fc->killsb){++++}-{4:4}, at: fuse_notify fs/fuse/dev.c:2047 [inline] #0: ffff8880227f9350 (&fc->killsb){++++}-{4:4}, at: fuse_dev_do_write+0x49cc/0x5900 fs/fuse/dev.c:2132 #1: ffff8880b8639998 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:605 #2: ffffffff8ed3dfa0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #2: ffffffff8ed3dfa0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #2: ffffffff8ed3dfa0 (rcu_read_lock){....}-{1:3}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2362 [inline] #2: ffffffff8ed3dfa0 (rcu_read_lock){....}-{1:3}, at: bpf_trace_run4+0x246/0x5a0 kernel/trace/bpf_trace.c:2406 stack backtrace: CPU: 0 UID: 0 PID: 6863 Comm: syz.3.263 Not tainted 6.15.0-rc2-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call Trace: __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 __copy_to_user_inatomic include/linux/uaccess.h:132 [inline] copy_to_user_nofault+0x84/0x150 mm/maccess.c:156 bpf_prog_6303d92f98284ad8+0x44/0x48 bpf_dispatcher_nop_func include/linux/bpf.h:1316 [inline] __bpf_prog_run include/linux/filter.h:718 [inline] bpf_prog_run include/linux/filter.h:725 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2363 [inline] bpf_trace_run4+0x336/0x5a0 kernel/trace/bpf_trace.c:2406 __bpf_trace_sched_switch+0x296/0x3d0 include/trace/events/sched.h:220 __traceiter_sched_switch+0x98/0xd0 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+0x28bb/0x51f0 kernel/sched/core.c:6764 preempt_schedule_common+0x84/0xd0 kernel/sched/core.c:6947 preempt_schedule+0xe4/0xf0 kernel/sched/core.c:6971 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline] _raw_spin_unlock+0x3e/0x50 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:391 [inline] ilookup5_nowait fs/inode.c:1582 [inline] ilookup5+0xb0/0x160 fs/inode.c:1610 fuse_ilookup+0x164/0x250 fs/fuse/inode.c:542 fuse_reverse_inval_entry+0x33/0x720 fs/fuse/dir.c:1395 fuse_notify fs/fuse/dev.c:-1 [inline] fuse_dev_do_write+0x4af9/0x5900 fs/fuse/dev.c:2132 fuse_dev_write+0x179/0x220 fs/fuse/dev.c:2216 new_sync_write fs/read_write.c:591 [inline] vfs_write+0x70f/0xd10 fs/read_write.c:684 ksys_write+0x19d/0x2d0 fs/read_write.c:736 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f4b5998d169 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f4b5a7b6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f4b59ba6080 RCX: 00007f4b5998d169 RDX: 000000000000002a RSI: 0000200000000080 RDI: 0000000000000009 RBP: 00007f4b5a7b6090 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 0000000000000000 R14: 00007f4b59ba6080 R15: 00007ffea90c3308