FAULT_INJECTION: forcing a failure. name fail_usercopy, interval 1, probability 0, space 0, times 0 ====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.5.974/9467 is trying to acquire lock: ffffffff8cd24120 (console_owner){-...}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:339 [inline] ffffffff8cd24120 (console_owner){-...}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:232 [inline] ffffffff8cd24120 (console_owner){-...}-{0:0}, at: console_srcu_read_lock kernel/printk/printk.c:292 [inline] ffffffff8cd24120 (console_owner){-...}-{0:0}, at: console_flush_all+0x10f/0xd00 kernel/printk/printk.c:2992 but task is already holding lock: ffff8880b8e3c218 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:558 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:558 raw_spin_rq_lock kernel/sched/sched.h:1372 [inline] rq_lock kernel/sched/sched.h:1681 [inline] task_fork_fair+0x62/0x1f0 kernel/sched/fair.c:12675 sched_cgroup_fork+0x333/0x3c0 kernel/sched/core.c:4816 copy_process+0x21e4/0x3d70 kernel/fork.c:2614 kernel_clone+0x21b/0x840 kernel/fork.c:2914 user_mode_thread+0xde/0x130 kernel/fork.c:2992 rest_init+0x27/0x300 init/main.c:709 arch_call_rest_init+0xe/0x10 init/main.c:841 start_kernel+0x459/0x4e0 init/main.c:1086 x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:555 copy_bootdata+0x0/0xe0 arch/x86/kernel/head64.c:536 secondary_startup_64_no_verify+0x179/0x17b -> #3 (&p->pi_lock){-.-.}-{2:2}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xa8/0xf0 kernel/locking/spinlock.c:162 class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:522 [inline] try_to_wake_up+0x60/0x1140 kernel/sched/core.c:4232 __wake_up_common+0x2a4/0x4e0 kernel/sched/wait.c:107 __wake_up_common_lock kernel/sched/wait.c:138 [inline] __wake_up+0x112/0x190 kernel/sched/wait.c:160 tty_port_default_wakeup+0xa2/0xf0 drivers/tty/tty_port.c:69 serial8250_tx_chars+0x6bd/0x8a0 drivers/tty/serial/8250/8250_port.c:1837 serial8250_handle_irq+0x534/0x6e0 drivers/tty/serial/8250/8250_port.c:1944 serial8250_default_handle_irq+0xb8/0x1a0 drivers/tty/serial/8250/8250_port.c:1964 serial8250_interrupt+0x9f/0x1c0 drivers/tty/serial/8250/8250_core.c:127 __handle_irq_event_percpu+0x276/0x930 kernel/irq/handle.c:158 handle_irq_event_percpu kernel/irq/handle.c:193 [inline] handle_irq_event+0x8b/0x1e0 kernel/irq/handle.c:210 handle_edge_irq+0x247/0xb30 kernel/irq/chip.c:831 generic_handle_irq_desc include/linux/irqdesc.h:161 [inline] handle_irq arch/x86/kernel/irq.c:240 [inline] __common_interrupt+0x13b/0x230 arch/x86/kernel/irq.c:259 common_interrupt+0xb4/0xd0 arch/x86/kernel/irq.c:249 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:678 __sanitizer_cov_trace_switch+0x6c/0x120 kernel/kcov.c:349 unwind_next_frame+0xe46/0x2970 arch/x86/kernel/unwind_orc.c:581 arch_stack_walk+0x144/0x190 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4e/0x70 mm/kasan/common.c:52 kasan_save_free_info+0x2e/0x50 mm/kasan/generic.c:522 ____kasan_slab_free+0x126/0x1e0 mm/kasan/common.c:236 kasan_slab_free include/linux/kasan.h:164 [inline] slab_free_hook mm/slub.c:1811 [inline] slab_free_freelist_hook+0x130/0x1b0 mm/slub.c:1837 slab_free mm/slub.c:3830 [inline] kmem_cache_free+0xf8/0x280 mm/slub.c:3852 anon_vma_chain_free mm/rmap.c:147 [inline] unlink_anon_vmas+0x612/0x660 mm/rmap.c:448 free_pgtables+0x4ff/0x770 mm/memory.c:399 exit_mmap+0x3e8/0xb50 mm/mmap.c:3313 __mmput+0x118/0x3c0 kernel/fork.c:1355 exec_mmap+0x584/0x640 fs/exec.c:1036 begin_new_exec+0xa2e/0x1eb0 fs/exec.c:1294 load_elf_binary+0x9a0/0x2700 fs/binfmt_elf.c:1027 search_binary_handler fs/exec.c:1775 [inline] exec_binprm fs/exec.c:1817 [inline] bprm_execve+0xaeb/0x16f0 fs/exec.c:1892 do_execveat_common+0x51b/0x6c0 fs/exec.c:1998 do_execve fs/exec.c:2072 [inline] __do_sys_execve fs/exec.c:2148 [inline] __se_sys_execve fs/exec.c:2143 [inline] __x64_sys_execve+0x92/0xa0 fs/exec.c:2143 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 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+0xa8/0xf0 kernel/locking/spinlock.c:162 __wake_up_common_lock kernel/sched/wait.c:137 [inline] __wake_up+0xf8/0x190 kernel/sched/wait.c:160 tty_port_default_wakeup+0xa2/0xf0 drivers/tty/tty_port.c:69 serial8250_tx_chars+0x6bd/0x8a0 drivers/tty/serial/8250/8250_port.c:1837 serial8250_handle_irq+0x534/0x6e0 drivers/tty/serial/8250/8250_port.c:1944 serial8250_default_handle_irq+0xb8/0x1a0 drivers/tty/serial/8250/8250_port.c:1964 serial8250_interrupt+0x9f/0x1c0 drivers/tty/serial/8250/8250_core.c:127 __handle_irq_event_percpu+0x276/0x930 kernel/irq/handle.c:158 handle_irq_event_percpu kernel/irq/handle.c:193 [inline] handle_irq_event+0x8b/0x1e0 kernel/irq/handle.c:210 handle_edge_irq+0x247/0xb30 kernel/irq/chip.c:831 generic_handle_irq_desc include/linux/irqdesc.h:161 [inline] handle_irq arch/x86/kernel/irq.c:240 [inline] __common_interrupt+0x13b/0x230 arch/x86/kernel/irq.c:259 common_interrupt+0xb4/0xd0 arch/x86/kernel/irq.c:249 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:678 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] _raw_spin_unlock_irqrestore+0xa9/0x110 kernel/locking/spinlock.c:194 spin_unlock_irqrestore include/linux/spinlock.h:406 [inline] uart_write+0x45b/0x5d0 drivers/tty/serial/serial_core.c:634 process_output_block drivers/tty/n_tty.c:580 [inline] n_tty_write+0xd27/0x11d0 drivers/tty/n_tty.c:2395 iterate_tty_write drivers/tty/tty_io.c:1017 [inline] file_tty_write+0x54b/0x980 drivers/tty/tty_io.c:1088 call_write_iter include/linux/fs.h:2018 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x43b/0x940 fs/read_write.c:584 ksys_write+0x147/0x250 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 -> #1 (&port_lock_key){-.-.}-{2:2}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xa8/0xf0 kernel/locking/spinlock.c:162 serial8250_console_write+0x16d/0x17a0 drivers/tty/serial/8250/8250_port.c:3433 console_emit_next_record kernel/printk/printk.c:2944 [inline] console_flush_all+0x6cd/0xd00 kernel/printk/printk.c:3000 console_unlock+0xae/0x340 kernel/printk/printk.c:3069 vprintk_emit+0x477/0x600 kernel/printk/printk.c:2341 _printk+0xd0/0x110 kernel/printk/printk.c:2366 register_console+0x91b/0xe60 kernel/printk/printk.c:3583 univ8250_console_init+0x45/0x50 drivers/tty/serial/8250/8250_core.c:717 console_init+0x17b/0x5e0 kernel/printk/printk.c:3726 start_kernel+0x2c0/0x4e0 init/main.c:1022 x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:555 copy_bootdata+0x0/0xe0 arch/x86/kernel/head64.c:536 secondary_startup_64_no_verify+0x179/0x17b -> #0 (console_owner){-...}-{0:0}: check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain kernel/locking/lockdep.c:3869 [inline] __lock_acquire+0x2ddb/0x7c80 kernel/locking/lockdep.c:5137 lock_acquire+0x197/0x410 kernel/locking/lockdep.c:5754 console_lock_spinning_enable kernel/printk/printk.c:1871 [inline] console_emit_next_record kernel/printk/printk.c:2938 [inline] console_flush_all+0x693/0xd00 kernel/printk/printk.c:3000 console_unlock+0xae/0x340 kernel/printk/printk.c:3069 vprintk_emit+0x477/0x600 kernel/printk/printk.c:2341 _printk+0xd0/0x110 kernel/printk/printk.c:2366 fail_dump lib/fault-inject.c:45 [inline] should_fail_ex+0x37e/0x4d0 lib/fault-inject.c:153 __copy_to_user_inatomic include/linux/uaccess.h:123 [inline] copy_to_user_nofault+0x85/0x140 mm/maccess.c:149 bpf_prog_19072b5a3fcf5d64+0x40/0x44 bpf_dispatcher_nop_func include/linux/bpf.h:1224 [inline] __bpf_prog_run include/linux/filter.h:605 [inline] bpf_prog_run include/linux/filter.h:619 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2322 [inline] bpf_trace_run4+0x379/0x420 kernel/trace/bpf_trace.c:2363 __bpf_trace_sched_switch+0x17b/0x1e0 include/trace/events/sched.h:222 __traceiter_sched_switch+0x93/0xc0 include/trace/events/sched.h:222 trace_sched_switch include/trace/events/sched.h:222 [inline] __schedule+0x2197/0x44d0 kernel/sched/core.c:6696 preempt_schedule_irq+0xb5/0x140 kernel/sched/core.c:7009 irqentry_exit+0x67/0x70 kernel/entry/common.c:438 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 exit_to_user_mode_loop+0x40/0x110 kernel/entry/common.c:164 exit_to_user_mode_prepare+0xf6/0x180 kernel/entry/common.c:210 irqentry_exit_to_user_mode+0x9/0x40 kernel/entry/common.c:315 exc_general_protection+0x170/0x200 arch/x86/kernel/traps.c:745 asm_exc_general_protection+0x26/0x30 arch/x86/include/asm/idtentry.h:602 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.5.974/9467: #0: ffff8880b8e3c218 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:558 #1: ffffffff8cd2fee0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #1: ffffffff8cd2fee0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #1: ffffffff8cd2fee0 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2321 [inline] #1: ffffffff8cd2fee0 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run4+0xfd/0x420 kernel/trace/bpf_trace.c:2363 #2: ffffffff8cd24200 (console_lock){+.+.}-{0:0}, at: _printk+0xd0/0x110 kernel/printk/printk.c:2366 #3: ffffffff8cc0ba10 (console_srcu){....}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:339 [inline] #3: ffffffff8cc0ba10 (console_srcu){....}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:232 [inline] #3: ffffffff8cc0ba10 (console_srcu){....}-{0:0}, at: console_srcu_read_lock kernel/printk/printk.c:292 [inline] #3: ffffffff8cc0ba10 (console_srcu){....}-{0:0}, at: console_flush_all+0x10f/0xd00 kernel/printk/printk.c:2992 stack backtrace: CPU: 0 PID: 9467 Comm: syz.5.974 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Call Trace: dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106 check_noncircular+0x2bd/0x3c0 kernel/locking/lockdep.c:2187 check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain kernel/locking/lockdep.c:3869 [inline] __lock_acquire+0x2ddb/0x7c80 kernel/locking/lockdep.c:5137 lock_acquire+0x197/0x410 kernel/locking/lockdep.c:5754 console_lock_spinning_enable kernel/printk/printk.c:1871 [inline] console_emit_next_record kernel/printk/printk.c:2938 [inline] console_flush_all+0x693/0xd00 kernel/printk/printk.c:3000 console_unlock+0xae/0x340 kernel/printk/printk.c:3069 vprintk_emit+0x477/0x600 kernel/printk/printk.c:2341 _printk+0xd0/0x110 kernel/printk/printk.c:2366 fail_dump lib/fault-inject.c:45 [inline] should_fail_ex+0x37e/0x4d0 lib/fault-inject.c:153 __copy_to_user_inatomic include/linux/uaccess.h:123 [inline] copy_to_user_nofault+0x85/0x140 mm/maccess.c:149 bpf_prog_19072b5a3fcf5d64+0x40/0x44 bpf_dispatcher_nop_func include/linux/bpf.h:1224 [inline] __bpf_prog_run include/linux/filter.h:605 [inline] bpf_prog_run include/linux/filter.h:619 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2322 [inline] bpf_trace_run4+0x379/0x420 kernel/trace/bpf_trace.c:2363 __bpf_trace_sched_switch+0x17b/0x1e0 include/trace/events/sched.h:222 __traceiter_sched_switch+0x93/0xc0 include/trace/events/sched.h:222 trace_sched_switch include/trace/events/sched.h:222 [inline] __schedule+0x2197/0x44d0 kernel/sched/core.c:6696 preempt_schedule_irq+0xb5/0x140 kernel/sched/core.c:7009 irqentry_exit+0x67/0x70 kernel/entry/common.c:438 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0010:exit_to_user_mode_loop+0x40/0x110 kernel/entry/common.c:164 Code: fb eb 1d e8 52 59 fc 08 65 48 8b 05 4a 2e 91 7e 4c 8b 30 41 f7 c6 0e 30 02 00 0f 84 c4 00 00 00 e8 15 69 19 00 fb 41 f6 c6 08 <74> 05 e8 b9 85 04 09 41 f7 c6 00 10 00 00 74 08 48 89 df e8 58 e9 RSP: 0000:ffffc9000d05fe58 EFLAGS: 00000246 RAX: 77c6bfb85c581c00 RBX: ffffc9000d05ff58 RCX: 77c6bfb85c581c00 RDX: dffffc0000000000 RSI: ffffffff8aaabce0 RDI: ffffffff8afc6b00 RBP: ffffc9000d05ff48 R08: ffffffff8e4a8d6f R09: 1ffffffff1c951ad R10: dffffc0000000000 R11: fffffbfff1c951ae R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000004 R15: ffff88802ac93c00 exit_to_user_mode_prepare+0xf6/0x180 kernel/entry/common.c:210 irqentry_exit_to_user_mode+0x9/0x40 kernel/entry/common.c:315 exc_general_protection+0x170/0x200 arch/x86/kernel/traps.c:745 asm_exc_general_protection+0x26/0x30 arch/x86/include/asm/idtentry.h:602 RIP: 0033:0x7fe7c3768179 Code: f8 77 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 89 f8 48 89 fa c5 f9 ef c0 25 ff 0f 00 00 3d e0 0f 00 00 0f 87 27 01 00 00 fd 74 0f c5 fd d7 c1 85 c0 74 5b f3 0f bc c0 e9 30 01 00 00 66 RSP: 002b:00007fe7c465d7c8 EFLAGS: 00010283 RAX: 0000000000000999 RBX: 00007fe7c465dd30 RCX: 00007fe7c39ab120 RDX: 9999999999999999 RSI: 00007fe7c3813ca9 RDI: 9999999999999999 RBP: 000000000000000b R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000000 R12: 0000000000000073 R13: 00007fe7c465deb0 R14: 9999999999999999 R15: 0000000000000000 CPU: 0 PID: 9467 Comm: syz.5.974 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Call Trace: dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106 fail_dump lib/fault-inject.c:52 [inline] should_fail_ex+0x39d/0x4d0 lib/fault-inject.c:153 __copy_to_user_inatomic include/linux/uaccess.h:123 [inline] copy_to_user_nofault+0x85/0x140 mm/maccess.c:149 bpf_prog_19072b5a3fcf5d64+0x40/0x44 bpf_dispatcher_nop_func include/linux/bpf.h:1224 [inline] __bpf_prog_run include/linux/filter.h:605 [inline] bpf_prog_run include/linux/filter.h:619 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2322 [inline] bpf_trace_run4+0x379/0x420 kernel/trace/bpf_trace.c:2363 __bpf_trace_sched_switch+0x17b/0x1e0 include/trace/events/sched.h:222 __traceiter_sched_switch+0x93/0xc0 include/trace/events/sched.h:222 trace_sched_switch include/trace/events/sched.h:222 [inline] __schedule+0x2197/0x44d0 kernel/sched/core.c:6696 preempt_schedule_irq+0xb5/0x140 kernel/sched/core.c:7009 irqentry_exit+0x67/0x70 kernel/entry/common.c:438 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0010:exit_to_user_mode_loop+0x40/0x110 kernel/entry/common.c:164 Code: fb eb 1d e8 52 59 fc 08 65 48 8b 05 4a 2e 91 7e 4c 8b 30 41 f7 c6 0e 30 02 00 0f 84 c4 00 00 00 e8 15 69 19 00 fb 41 f6 c6 08 <74> 05 e8 b9 85 04 09 41 f7 c6 00 10 00 00 74 08 48 89 df e8 58 e9 RSP: 0000:ffffc9000d05fe58 EFLAGS: 00000246 RAX: 77c6bfb85c581c00 RBX: ffffc9000d05ff58 RCX: 77c6bfb85c581c00 RDX: dffffc0000000000 RSI: ffffffff8aaabce0 RDI: ffffffff8afc6b00 RBP: ffffc9000d05ff48 R08: ffffffff8e4a8d6f R09: 1ffffffff1c951ad R10: dffffc0000000000 R11: fffffbfff1c951ae R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000004 R15: ffff88802ac93c00 exit_to_user_mode_prepare+0xf6/0x180 kernel/entry/common.c:210 irqentry_exit_to_user_mode+0x9/0x40 kernel/entry/common.c:315 exc_general_protection+0x170/0x200 arch/x86/kernel/traps.c:745 asm_exc_general_protection+0x26/0x30 arch/x86/include/asm/idtentry.h:602 RIP: 0033:0x7fe7c3768179 Code: f8 77 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 89 f8 48 89 fa c5 f9 ef c0 25 ff 0f 00 00 3d e0 0f 00 00 0f 87 27 01 00 00 fd 74 0f c5 fd d7 c1 85 c0 74 5b f3 0f bc c0 e9 30 01 00 00 66 RSP: 002b:00007fe7c465d7c8 EFLAGS: 00010283 RAX: 0000000000000999 RBX: 00007fe7c465dd30 RCX: 00007fe7c39ab120 RDX: 9999999999999999 RSI: 00007fe7c3813ca9 RDI: 9999999999999999 RBP: 000000000000000b R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000000 R12: 0000000000000073 R13: 00007fe7c465deb0 R14: 9999999999999999 R15: 0000000000000000 ---------------- Code disassembly (best guess): 0: fb sti 1: eb 1d jmp 0x20 3: e8 52 59 fc 08 call 0x8fc595a 8: 65 48 8b 05 4a 2e 91 mov %gs:0x7e912e4a(%rip),%rax # 0x7e912e5a f: 7e 10: 4c 8b 30 mov (%rax),%r14 13: 41 f7 c6 0e 30 02 00 test $0x2300e,%r14d 1a: 0f 84 c4 00 00 00 je 0xe4 20: e8 15 69 19 00 call 0x19693a 25: fb sti 26: 41 f6 c6 08 test $0x8,%r14b * 2a: 74 05 je 0x31 <-- trapping instruction 2c: e8 b9 85 04 09 call 0x90485ea 31: 41 f7 c6 00 10 00 00 test $0x1000,%r14d 38: 74 08 je 0x42 3a: 48 89 df mov %rbx,%rdi 3d: e8 .byte 0xe8 3e: 58 pop %rax 3f: e9 .byte 0xe9