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.4.1333/9025 is trying to acquire lock: ffffffff8c1110c0 (console_owner){-.-.}-{0:0}, at: console_lock_spinning_enable+0x2c/0x60 kernel/printk/printk.c:1802 but task is already holding lock: ffff8880b903a358 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:475 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:368 raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:475 raw_spin_rq_lock kernel/sched/sched.h:1326 [inline] rq_lock kernel/sched/sched.h:1621 [inline] task_fork_fair+0x5c/0x350 kernel/sched/fair.c:11499 sched_cgroup_fork+0x2c6/0x320 kernel/sched/core.c:4485 copy_process+0x22d1/0x3e00 kernel/fork.c:2395 kernel_clone+0x219/0x930 kernel/fork.c:2679 kernel_thread+0xc8/0x120 kernel/fork.c:2731 rest_init+0x21/0x330 init/main.c:706 start_kernel+0x486/0x530 init/main.c:1140 secondary_startup_64_no_verify+0xb1/0xbb -> #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/0x1050 kernel/sched/core.c:4049 __wake_up_common+0x2a4/0x4e0 kernel/sched/wait.c:108 __wake_up_common_lock kernel/sched/wait.c:138 [inline] __wake_up+0x108/0x180 kernel/sched/wait.c:157 tty_port_default_wakeup+0xa5/0xf0 drivers/tty/tty_port.c:51 serial8250_tx_chars+0x629/0x830 drivers/tty/serial/8250/8250_port.c:1828 serial8250_handle_irq+0x519/0x610 drivers/tty/serial/8250/8250_port.c:1924 serial8250_default_handle_irq+0xb4/0x1a0 drivers/tty/serial/8250/8250_port.c:1941 serial8250_interrupt+0x9b/0x1c0 drivers/tty/serial/8250/8250_core.c:127 __handle_irq_event_percpu+0x291/0x9b0 kernel/irq/handle.c:156 handle_irq_event_percpu kernel/irq/handle.c:196 [inline] handle_irq_event+0xa5/0x220 kernel/irq/handle.c:213 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:667 preempt_count arch/x86/include/asm/preempt.h:27 [inline] check_kcov_mode kernel/kcov.c:172 [inline] __sanitizer_cov_trace_pc+0x13/0x60 kernel/kcov.c:206 validate_mm_rb+0x1de/0x230 mm/mmap.c:386 vma_rb_insert mm/mmap.c:458 [inline] __vma_link_rb+0x527/0x550 mm/mmap.c:657 __vma_link mm/mmap.c:683 [inline] __insert_vm_struct mm/mmap.c:719 [inline] __vma_adjust+0xf86/0x1c20 mm/mmap.c:933 vma_adjust include/linux/mm.h:2567 [inline] __split_vma+0x34b/0x410 mm/mmap.c:-1 __do_munmap+0x3eb/0xdc0 mm/mmap.c:2865 do_munmap mm/mmap.c:2910 [inline] munmap_vma_range mm/mmap.c:603 [inline] __mmap_region mm/mmap.c:1757 [inline] mmap_region+0x8bb/0x1660 mm/mmap.c:2933 do_mmap+0x81f/0xea0 mm/mmap.c:1586 vm_mmap_pgoff+0x1b2/0x2b0 mm/util.c:551 ksys_mmap_pgoff+0x542/0x780 mm/mmap.c:1635 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 -> #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+0xed/0x180 kernel/sched/wait.c:157 tty_port_default_wakeup+0xa5/0xf0 drivers/tty/tty_port.c:51 serial8250_tx_chars+0x629/0x830 drivers/tty/serial/8250/8250_port.c:1828 serial8250_handle_irq+0x519/0x610 drivers/tty/serial/8250/8250_port.c:1924 serial8250_default_handle_irq+0xb4/0x1a0 drivers/tty/serial/8250/8250_port.c:1941 serial8250_interrupt+0x9b/0x1c0 drivers/tty/serial/8250/8250_core.c:127 __handle_irq_event_percpu+0x291/0x9b0 kernel/irq/handle.c:156 handle_irq_event_percpu kernel/irq/handle.c:196 [inline] handle_irq_event+0xa5/0x220 kernel/irq/handle.c:213 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:667 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:729 default_idle_call+0x81/0xc0 kernel/sched/idle.c:112 cpuidle_idle_call kernel/sched/idle.c:194 [inline] do_idle+0x21b/0x5b0 kernel/sched/idle.c:306 cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:403 start_kernel+0x486/0x530 init/main.c:1140 secondary_startup_64_no_verify+0xb1/0xbb -> #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+0x170/0xf80 drivers/tty/serial/8250/8250_port.c:3362 call_console_drivers kernel/printk/printk.c:-1 [inline] console_unlock+0xc86/0x1200 kernel/printk/printk.c:2744 vprintk_emit+0xc0/0x150 kernel/printk/printk.c:2274 _printk+0xcc/0x110 kernel/printk/printk.c:2299 register_console+0x682/0x960 kernel/printk/printk.c:3107 univ8250_console_init+0x41/0x50 drivers/tty/serial/8250/8250_core.c:690 console_init+0x177/0x5d0 kernel/printk/printk.c:3207 start_kernel+0x2f9/0x530 init/main.c:1076 secondary_startup_64_no_verify+0xb1/0xbb -> #0 (console_owner){-.-.}-{0:0}: check_prev_add kernel/locking/lockdep.c:3053 [inline] check_prevs_add kernel/locking/lockdep.c:3172 [inline] validate_chain kernel/locking/lockdep.c:3788 [inline] __lock_acquire+0x2c33/0x7c60 kernel/locking/lockdep.c:5012 lock_acquire+0x197/0x3f0 kernel/locking/lockdep.c:5623 console_lock_spinning_enable+0x51/0x60 kernel/printk/printk.c:1805 console_unlock+0x9f8/0x1200 kernel/printk/printk.c:2741 vprintk_emit+0xc0/0x150 kernel/printk/printk.c:2274 _printk+0xcc/0x110 kernel/printk/printk.c:2299 fail_dump lib/fault-inject.c:45 [inline] should_fail+0x36d/0x4c0 lib/fault-inject.c:146 strncpy_from_user+0x32/0x360 lib/strncpy_from_user.c:118 strncpy_from_user_nofault+0x6d/0x140 mm/maccess.c:295 bpf_probe_read_user_str_common kernel/trace/bpf_trace.c:194 [inline] ____bpf_probe_read_compat_str kernel/trace/bpf_trace.c:300 [inline] bpf_probe_read_compat_str+0xdd/0x170 kernel/trace/bpf_trace.c:296 bpf_prog_1ccb8ba97563bf77+0x38/0xdec bpf_dispatcher_nop_func include/linux/bpf.h:888 [inline] __bpf_prog_run include/linux/filter.h:621 [inline] bpf_prog_run include/linux/filter.h:635 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:1878 [inline] bpf_trace_run2+0x242/0x2d0 kernel/trace/bpf_trace.c:1915 __traceiter_tlb_flush+0x69/0xb0 include/trace/events/tlb.h:38 trace_tlb_flush+0xe6/0x110 include/trace/events/tlb.h:38 switch_mm_irqs_off+0x6e3/0x9a0 arch/x86/mm/tlb.c:-1 context_switch kernel/sched/core.c:5035 [inline] __schedule+0x1024/0x4390 kernel/sched/core.c:6395 preempt_schedule_irq+0xb1/0x150 kernel/sched/core.c:6799 irqentry_exit+0x63/0x70 kernel/entry/common.c:432 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 __sanitizer_cov_trace_pc+0x0/0x60 handle_mounts fs/namei.c:1486 [inline] step_into+0xfc/0xd00 fs/namei.c:1806 link_path_walk+0x662/0xd40 fs/namei.c:-1 path_parentat fs/namei.c:2502 [inline] __filename_parentat+0x1f3/0x5f0 fs/namei.c:2526 filename_parentat fs/namei.c:2544 [inline] filename_create+0xcc/0x450 fs/namei.c:3816 do_mkdirat+0x9d/0x5a0 fs/namei.c:4080 __do_sys_mkdirat fs/namei.c:4105 [inline] __se_sys_mkdirat fs/namei.c:4103 [inline] __x64_sys_mkdirat+0x85/0x90 fs/namei.c:4103 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 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.4.1333/9025: #0: ffff8880b903a358 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:475 #1: ffffffff8c11c660 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:311 #2: ffffffff8c1111a0 (console_lock){+.+.}-{0:0}, at: vprintk_emit+0xa7/0x150 kernel/printk/printk.c:2273 stack backtrace: CPU: 0 PID: 9025 Comm: syz.4.1333 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Call Trace: dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106 check_noncircular+0x274/0x310 kernel/locking/lockdep.c:2133 check_prev_add kernel/locking/lockdep.c:3053 [inline] check_prevs_add kernel/locking/lockdep.c:3172 [inline] validate_chain kernel/locking/lockdep.c:3788 [inline] __lock_acquire+0x2c33/0x7c60 kernel/locking/lockdep.c:5012 lock_acquire+0x197/0x3f0 kernel/locking/lockdep.c:5623 console_lock_spinning_enable+0x51/0x60 kernel/printk/printk.c:1805 console_unlock+0x9f8/0x1200 kernel/printk/printk.c:2741 vprintk_emit+0xc0/0x150 kernel/printk/printk.c:2274 _printk+0xcc/0x110 kernel/printk/printk.c:2299 fail_dump lib/fault-inject.c:45 [inline] should_fail+0x36d/0x4c0 lib/fault-inject.c:146 strncpy_from_user+0x32/0x360 lib/strncpy_from_user.c:118 strncpy_from_user_nofault+0x6d/0x140 mm/maccess.c:295 bpf_probe_read_user_str_common kernel/trace/bpf_trace.c:194 [inline] ____bpf_probe_read_compat_str kernel/trace/bpf_trace.c:300 [inline] bpf_probe_read_compat_str+0xdd/0x170 kernel/trace/bpf_trace.c:296 bpf_prog_1ccb8ba97563bf77+0x38/0xdec bpf_dispatcher_nop_func include/linux/bpf.h:888 [inline] __bpf_prog_run include/linux/filter.h:621 [inline] bpf_prog_run include/linux/filter.h:635 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:1878 [inline] bpf_trace_run2+0x242/0x2d0 kernel/trace/bpf_trace.c:1915 __traceiter_tlb_flush+0x69/0xb0 include/trace/events/tlb.h:38 trace_tlb_flush+0xe6/0x110 include/trace/events/tlb.h:38 switch_mm_irqs_off+0x6e3/0x9a0 arch/x86/mm/tlb.c:-1 context_switch kernel/sched/core.c:5035 [inline] __schedule+0x1024/0x4390 kernel/sched/core.c:6395 preempt_schedule_irq+0xb1/0x150 kernel/sched/core.c:6799 irqentry_exit+0x63/0x70 kernel/entry/common.c:432 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x60 kernel/kcov.c:202 Code: 66 2e 0f 1f 84 00 00 00 00 00 53 48 89 fb e8 17 00 00 00 48 8b 3d 90 cd f1 0b 48 89 de 5b e9 47 9e 43 00 00 00 cc cc 00 00 cc <48> 8b 04 24 65 48 8b 0d 64 a5 8a 7e 65 8b 15 65 a5 8a 7e 81 e2 00 RSP: 0018:ffffc90005217918 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffffc90005217be0 RCX: ffff888024a03b80 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc90005217a30 R08: 0000000000000000 R09: fffffbfff1ad32b6 R10: fffffbfff1ad32b6 R11: 1ffffffff1ad32b5 R12: dffffc0000000000 R13: 1ffff92000a42f83 R14: 0000000000000010 R15: ffff8880762de000 handle_mounts fs/namei.c:1486 [inline] step_into+0xfc/0xd00 fs/namei.c:1806 link_path_walk+0x662/0xd40 fs/namei.c:-1 path_parentat fs/namei.c:2502 [inline] __filename_parentat+0x1f3/0x5f0 fs/namei.c:2526 filename_parentat fs/namei.c:2544 [inline] filename_create+0xcc/0x450 fs/namei.c:3816 do_mkdirat+0x9d/0x5a0 fs/namei.c:4080 __do_sys_mkdirat fs/namei.c:4105 [inline] __se_sys_mkdirat fs/namei.c:4103 [inline] __x64_sys_mkdirat+0x85/0x90 fs/namei.c:4103 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f5dfb83aec9 Code: Unable to access opcode bytes at RIP 0x7f5dfb83ae9f. RSP: 002b:00007f5df9aa2038 EFLAGS: 00000246 ORIG_RAX: 0000000000000102 RAX: ffffffffffffffda RBX: 00007f5dfba91fa0 RCX: 00007f5dfb83aec9 RDX: 00000000000001ff RSI: 0000200000000000 RDI: ffffffffffffff9c RBP: 00007f5df9aa2090 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 00007f5dfba92038 R14: 00007f5dfba91fa0 R15: 00007ffdb86343c8 CPU: 0 PID: 9025 Comm: syz.4.1333 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Call Trace: dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106 fail_dump lib/fault-inject.c:52 [inline] should_fail+0x38c/0x4c0 lib/fault-inject.c:146 strncpy_from_user+0x32/0x360 lib/strncpy_from_user.c:118 strncpy_from_user_nofault+0x6d/0x140 mm/maccess.c:295 bpf_probe_read_user_str_common kernel/trace/bpf_trace.c:194 [inline] ____bpf_probe_read_compat_str kernel/trace/bpf_trace.c:300 [inline] bpf_probe_read_compat_str+0xdd/0x170 kernel/trace/bpf_trace.c:296 bpf_prog_1ccb8ba97563bf77+0x38/0xdec bpf_dispatcher_nop_func include/linux/bpf.h:888 [inline] __bpf_prog_run include/linux/filter.h:621 [inline] bpf_prog_run include/linux/filter.h:635 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:1878 [inline] bpf_trace_run2+0x242/0x2d0 kernel/trace/bpf_trace.c:1915 __traceiter_tlb_flush+0x69/0xb0 include/trace/events/tlb.h:38 trace_tlb_flush+0xe6/0x110 include/trace/events/tlb.h:38 switch_mm_irqs_off+0x6e3/0x9a0 arch/x86/mm/tlb.c:-1 context_switch kernel/sched/core.c:5035 [inline] __schedule+0x1024/0x4390 kernel/sched/core.c:6395 preempt_schedule_irq+0xb1/0x150 kernel/sched/core.c:6799 irqentry_exit+0x63/0x70 kernel/entry/common.c:432 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x60 kernel/kcov.c:202 Code: 66 2e 0f 1f 84 00 00 00 00 00 53 48 89 fb e8 17 00 00 00 48 8b 3d 90 cd f1 0b 48 89 de 5b e9 47 9e 43 00 00 00 cc cc 00 00 cc <48> 8b 04 24 65 48 8b 0d 64 a5 8a 7e 65 8b 15 65 a5 8a 7e 81 e2 00 RSP: 0018:ffffc90005217918 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffffc90005217be0 RCX: ffff888024a03b80 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc90005217a30 R08: 0000000000000000 R09: fffffbfff1ad32b6 R10: fffffbfff1ad32b6 R11: 1ffffffff1ad32b5 R12: dffffc0000000000 R13: 1ffff92000a42f83 R14: 0000000000000010 R15: ffff8880762de000 handle_mounts fs/namei.c:1486 [inline] step_into+0xfc/0xd00 fs/namei.c:1806 link_path_walk+0x662/0xd40 fs/namei.c:-1 path_parentat fs/namei.c:2502 [inline] __filename_parentat+0x1f3/0x5f0 fs/namei.c:2526 filename_parentat fs/namei.c:2544 [inline] filename_create+0xcc/0x450 fs/namei.c:3816 do_mkdirat+0x9d/0x5a0 fs/namei.c:4080 __do_sys_mkdirat fs/namei.c:4105 [inline] __se_sys_mkdirat fs/namei.c:4103 [inline] __x64_sys_mkdirat+0x85/0x90 fs/namei.c:4103 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f5dfb83aec9 Code: Unable to access opcode bytes at RIP 0x7f5dfb83ae9f. RSP: 002b:00007f5df9aa2038 EFLAGS: 00000246 ORIG_RAX: 0000000000000102 RAX: ffffffffffffffda RBX: 00007f5dfba91fa0 RCX: 00007f5dfb83aec9 RDX: 00000000000001ff RSI: 0000200000000000 RDI: ffffffffffffff9c RBP: 00007f5df9aa2090 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 00007f5dfba92038 R14: 00007f5dfba91fa0 R15: 00007ffdb86343c8 ---------------- Code disassembly (best guess): 0: 66 2e 0f 1f 84 00 00 cs nopw 0x0(%rax,%rax,1) 7: 00 00 00 a: 53 push %rbx b: 48 89 fb mov %rdi,%rbx e: e8 17 00 00 00 call 0x2a 13: 48 8b 3d 90 cd f1 0b mov 0xbf1cd90(%rip),%rdi # 0xbf1cdaa 1a: 48 89 de mov %rbx,%rsi 1d: 5b pop %rbx 1e: e9 47 9e 43 00 jmp 0x439e6a 23: 00 00 add %al,(%rax) 25: cc int3 26: cc int3 27: 00 00 add %al,(%rax) 29: cc int3 * 2a: 48 8b 04 24 mov (%rsp),%rax <-- trapping instruction 2e: 65 48 8b 0d 64 a5 8a mov %gs:0x7e8aa564(%rip),%rcx # 0x7e8aa59a 35: 7e 36: 65 8b 15 65 a5 8a 7e mov %gs:0x7e8aa565(%rip),%edx # 0x7e8aa5a2 3d: 81 .byte 0x81 3e: e2 00 loop 0x40