====================================================== WARNING: possible circular locking dependency detected 5.11.0-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.4/4137 is trying to acquire lock: ffffffff82ea29a0 (console_owner){....}-{0:0}, at: console_trylock_spinning kernel/printk/printk.c:1778 [inline] ffffffff82ea29a0 (console_owner){....}-{0:0}, at: vprintk_emit+0x1ce/0x2f0 kernel/printk/printk.c:2091 but task is already holding lock: ffff888237c2bc98 (&rq->lock){-.-.}-{2:2}, at: rq_lock kernel/sched/sched.h:1320 [inline] ffff888237c2bc98 (&rq->lock){-.-.}-{2:2}, at: __schedule+0xf0/0x950 kernel/sched/core.c:4995 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #4 (&rq->lock){-.-.}-{2:2}: __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x27/0x40 kernel/locking/spinlock.c:151 rq_lock kernel/sched/sched.h:1320 [inline] task_fork_fair+0x37/0x150 kernel/sched/fair.c:10767 sched_fork+0x111/0x290 kernel/sched/core.c:3778 copy_process+0x969/0x1c70 kernel/fork.c:2067 kernel_clone+0x96/0x3c0 kernel/fork.c:2462 kernel_thread+0x50/0x70 kernel/fork.c:2514 rest_init+0x19/0x23f init/main.c:686 start_kernel+0x492/0x4b2 init/main.c:1061 secondary_startup_64_no_verify+0xb0/0xbb -> #3 (&p->pi_lock){-.-.}-{2:2}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x36/0x50 kernel/locking/spinlock.c:159 try_to_wake_up+0x4e/0x710 kernel/sched/core.c:3349 __wake_up_common+0x88/0x1a0 kernel/sched/wait.c:108 __wake_up_common_lock+0x77/0xb0 kernel/sched/wait.c:138 tty_port_default_wakeup+0x16/0x30 drivers/tty/tty_port.c:50 serial8250_tx_chars+0x100/0x1e0 drivers/tty/serial/8250/8250_port.c:1832 serial8250_handle_irq.part.0+0xce/0xe0 drivers/tty/serial/8250/8250_port.c:1919 serial8250_handle_irq drivers/tty/serial/8250/8250_port.c:1892 [inline] serial8250_default_handle_irq+0x3d/0x80 drivers/tty/serial/8250/8250_port.c:1935 serial8250_interrupt+0x57/0xf0 drivers/tty/serial/8250/8250_core.c:126 __handle_irq_event_percpu+0xbd/0x260 kernel/irq/handle.c:156 handle_irq_event_percpu kernel/irq/handle.c:196 [inline] handle_irq_event+0x50/0xb0 kernel/irq/handle.c:213 handle_edge_irq+0x7c/0x210 kernel/irq/chip.c:819 asm_call_irq_on_stack+0xf/0x20 __run_irq_on_irqstack arch/x86/include/asm/irq_stack.h:48 [inline] run_irq_on_irqstack_cond arch/x86/include/asm/irq_stack.h:101 [inline] handle_irq arch/x86/kernel/irq.c:230 [inline] __common_interrupt arch/x86/kernel/irq.c:249 [inline] common_interrupt+0xe9/0x190 arch/x86/kernel/irq.c:239 asm_common_interrupt+0x1e/0x40 arch/x86/include/asm/idtentry.h:620 native_safe_halt arch/x86/include/asm/irqflags.h:60 [inline] arch_safe_halt arch/x86/include/asm/irqflags.h:103 [inline] acpi_safe_halt drivers/acpi/processor_idle.c:110 [inline] acpi_idle_do_entry+0x4f/0x60 drivers/acpi/processor_idle.c:516 acpi_idle_enter+0x78/0xb0 drivers/acpi/processor_idle.c:647 cpuidle_enter_state+0x8e/0x420 drivers/cpuidle/cpuidle.c:237 cpuidle_enter+0x24/0x40 drivers/cpuidle/cpuidle.c:351 call_cpuidle kernel/sched/idle.c:158 [inline] cpuidle_idle_call kernel/sched/idle.c:239 [inline] do_idle+0x1d9/0x270 kernel/sched/idle.c:299 cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:396 start_kernel+0x492/0x4b2 init/main.c:1061 secondary_startup_64_no_verify+0xb0/0xbb -> #2 (&tty->write_wait){-.-.}-{2:2}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x36/0x50 kernel/locking/spinlock.c:159 __wake_up_common_lock+0x5d/0xb0 kernel/sched/wait.c:137 tty_port_default_wakeup+0x16/0x30 drivers/tty/tty_port.c:50 serial8250_tx_chars+0x100/0x1e0 drivers/tty/serial/8250/8250_port.c:1832 serial8250_handle_irq.part.0+0xce/0xe0 drivers/tty/serial/8250/8250_port.c:1919 serial8250_handle_irq drivers/tty/serial/8250/8250_port.c:1892 [inline] serial8250_default_handle_irq+0x3d/0x80 drivers/tty/serial/8250/8250_port.c:1935 serial8250_interrupt+0x57/0xf0 drivers/tty/serial/8250/8250_core.c:126 __handle_irq_event_percpu+0xbd/0x260 kernel/irq/handle.c:156 handle_irq_event_percpu kernel/irq/handle.c:196 [inline] handle_irq_event+0x50/0xb0 kernel/irq/handle.c:213 handle_edge_irq+0x7c/0x210 kernel/irq/chip.c:819 asm_call_irq_on_stack+0xf/0x20 __run_irq_on_irqstack arch/x86/include/asm/irq_stack.h:48 [inline] run_irq_on_irqstack_cond arch/x86/include/asm/irq_stack.h:101 [inline] handle_irq arch/x86/kernel/irq.c:230 [inline] __common_interrupt arch/x86/kernel/irq.c:249 [inline] common_interrupt+0xe9/0x190 arch/x86/kernel/irq.c:239 asm_common_interrupt+0x1e/0x40 arch/x86/include/asm/idtentry.h:620 native_safe_halt arch/x86/include/asm/irqflags.h:60 [inline] arch_safe_halt arch/x86/include/asm/irqflags.h:103 [inline] acpi_safe_halt drivers/acpi/processor_idle.c:110 [inline] acpi_idle_do_entry+0x4f/0x60 drivers/acpi/processor_idle.c:516 acpi_idle_enter+0x78/0xb0 drivers/acpi/processor_idle.c:647 cpuidle_enter_state+0x8e/0x420 drivers/cpuidle/cpuidle.c:237 cpuidle_enter+0x24/0x40 drivers/cpuidle/cpuidle.c:351 call_cpuidle kernel/sched/idle.c:158 [inline] cpuidle_idle_call kernel/sched/idle.c:239 [inline] do_idle+0x1d9/0x270 kernel/sched/idle.c:299 cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:396 start_kernel+0x492/0x4b2 init/main.c:1061 secondary_startup_64_no_verify+0xb0/0xbb -> #1 (&port_lock_key){-.-.}-{2:2}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x36/0x50 kernel/locking/spinlock.c:159 serial8250_console_write+0x282/0x320 drivers/tty/serial/8250/8250_port.c:3292 call_console_drivers kernel/printk/printk.c:1856 [inline] console_unlock+0x40b/0x5a0 kernel/printk/printk.c:2570 vprintk_emit+0x133/0x2f0 kernel/printk/printk.c:2092 printk+0x53/0x6a kernel/printk/printk.c:2140 register_console+0x1b9/0x270 kernel/printk/printk.c:2921 univ8250_console_init+0x1f/0x22 drivers/tty/serial/8250/8250_core.c:690 console_init+0x16f/0x221 kernel/printk/printk.c:3021 start_kernel+0x3ca/0x4b2 init/main.c:989 secondary_startup_64_no_verify+0xb0/0xbb -> #0 (console_owner){....}-{0:0}: check_prev_add kernel/locking/lockdep.c:2868 [inline] check_prevs_add kernel/locking/lockdep.c:2993 [inline] validate_chain kernel/locking/lockdep.c:3608 [inline] __lock_acquire+0x10e3/0x1aa0 kernel/locking/lockdep.c:4832 lock_acquire kernel/locking/lockdep.c:5442 [inline] lock_acquire+0xbf/0x3b0 kernel/locking/lockdep.c:5407 console_trylock_spinning kernel/printk/printk.c:1799 [inline] vprintk_emit+0x201/0x2f0 kernel/printk/printk.c:2091 printk+0x53/0x6a kernel/printk/printk.c:2140 fail_dump lib/fault-inject.c:45 [inline] should_fail.cold+0x22/0x37 lib/fault-inject.c:146 strncpy_from_user+0x27/0x160 lib/strncpy_from_user.c:118 strncpy_from_user_nofault+0x24/0x60 mm/maccess.c:279 bpf_probe_read_user_str_common kernel/trace/bpf_trace.c:194 [inline] ____bpf_probe_read_user_str kernel/trace/bpf_trace.c:203 [inline] bpf_probe_read_user_str+0x18/0x40 kernel/trace/bpf_trace.c:200 ___bpf_prog_run+0xe0/0x19a0 kernel/bpf/core.c:1513 __bpf_prog_run32+0x34/0x60 kernel/bpf/core.c:1678 bpf_dispatcher_nop_func include/linux/bpf.h:651 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2085 [inline] bpf_trace_run3+0x74/0x160 kernel/trace/bpf_trace.c:2123 __traceiter_sched_switch+0x31/0x50 include/trace/events/sched.h:222 trace_sched_switch include/trace/events/sched.h:222 [inline] __schedule+0x3b8/0x950 kernel/sched/core.c:5075 schedule+0x56/0xc0 kernel/sched/core.c:5157 exit_to_user_mode_loop kernel/entry/common.c:162 [inline] exit_to_user_mode_prepare+0xf5/0x1d0 kernel/entry/common.c:201 __syscall_exit_to_user_mode_work kernel/entry/common.c:283 [inline] syscall_exit_to_user_mode+0x1a/0x60 kernel/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x44/0xa9 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 *** 2 locks held by syz-executor.4/4137: #0: ffff888237c2bc98 (&rq->lock){-.-.}-{2:2}, at: rq_lock kernel/sched/sched.h:1320 [inline] #0: ffff888237c2bc98 (&rq->lock){-.-.}-{2:2}, at: __schedule+0xf0/0x950 kernel/sched/core.c:4995 #1: ffffffff82f84d40 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run3+0x0/0x160 kernel/trace/bpf_trace.c:2122 stack backtrace: CPU: 0 PID: 4137 Comm: syz-executor.4 Not tainted 5.11.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023 Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x77/0x97 lib/dump_stack.c:120 check_noncircular+0xcc/0xe0 kernel/locking/lockdep.c:2117 check_prev_add kernel/locking/lockdep.c:2868 [inline] check_prevs_add kernel/locking/lockdep.c:2993 [inline] validate_chain kernel/locking/lockdep.c:3608 [inline] __lock_acquire+0x10e3/0x1aa0 kernel/locking/lockdep.c:4832 lock_acquire kernel/locking/lockdep.c:5442 [inline] lock_acquire+0xbf/0x3b0 kernel/locking/lockdep.c:5407 console_trylock_spinning kernel/printk/printk.c:1799 [inline] vprintk_emit+0x201/0x2f0 kernel/printk/printk.c:2091 printk+0x53/0x6a kernel/printk/printk.c:2140 fail_dump lib/fault-inject.c:45 [inline] should_fail.cold+0x22/0x37 lib/fault-inject.c:146 strncpy_from_user+0x27/0x160 lib/strncpy_from_user.c:118 strncpy_from_user_nofault+0x24/0x60 mm/maccess.c:279 bpf_probe_read_user_str_common kernel/trace/bpf_trace.c:194 [inline] ____bpf_probe_read_user_str kernel/trace/bpf_trace.c:203 [inline] bpf_probe_read_user_str+0x18/0x40 kernel/trace/bpf_trace.c:200 ___bpf_prog_run+0xe0/0x19a0 kernel/bpf/core.c:1513 __bpf_prog_run32+0x34/0x60 kernel/bpf/core.c:1678 bpf_dispatcher_nop_func include/linux/bpf.h:651 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2085 [inline] bpf_trace_run3+0x74/0x160 kernel/trace/bpf_trace.c:2123 __traceiter_sched_switch+0x31/0x50 include/trace/events/sched.h:222 trace_sched_switch include/trace/events/sched.h:222 [inline] __schedule+0x3b8/0x950 kernel/sched/core.c:5075 schedule+0x56/0xc0 kernel/sched/core.c:5157 exit_to_user_mode_loop kernel/entry/common.c:162 [inline] exit_to_user_mode_prepare+0xf5/0x1d0 kernel/entry/common.c:201 __syscall_exit_to_user_mode_work kernel/entry/common.c:283 [inline] syscall_exit_to_user_mode+0x1a/0x60 kernel/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7f35fbffbba9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f35fbb7e0c8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: 00000000000000d8 RBX: 00007f35fc11af80 RCX: 00007f35fbffbba9 RDX: 0000000000000000 RSI: 0000000020000940 RDI: 0000000000000003 RBP: 00007f35fbb7e120 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000002 R13: 000000000000000b R14: 00007f35fc11af80 R15: 00007ffc6298ac38