FAULT_INJECTION: forcing a failure. name fail_usercopy, interval 1, probability 0, space 0, times 0 ====================================================== WARNING: possible circular locking dependency detected 6.1.131-syzkaller #0 Not tainted ------------------------------------------------------ syz.3.273/5559 is trying to acquire lock: ffffffff8d20a578 ((console_sem).lock){-...}-{2:2}, at: down_trylock+0x1c/0xa0 kernel/locking/semaphore.c:139 but task is already holding lock: ffff8880b8e3a9d8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:537 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&rq->__lock){-.-.}-{2:2}: lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662 _raw_spin_lock_nested+0x2d/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+0x5d/0x350 kernel/sched/fair.c:11888 sched_cgroup_fork+0x374/0x400 kernel/sched/core.c:4684 copy_process+0x2482/0x40a0 kernel/fork.c:2383 kernel_clone+0x222/0x920 kernel/fork.c:2681 user_mode_thread+0x140/0x1b0 kernel/fork.c:2757 rest_init+0x23/0x300 init/main.c:698 start_kernel+0x0/0x53f init/main.c:893 start_kernel+0x496/0x53f init/main.c:1140 secondary_startup_64_no_verify+0xcf/0xdb -> #1 (&p->pi_lock){-.-.}-{2:2}: lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162 try_to_wake_up+0xad/0x1250 kernel/sched/core.c:4110 up+0x6e/0x90 kernel/locking/semaphore.c:191 __up_console_sem+0x11a/0x1e0 kernel/printk/printk.c:260 __console_unlock kernel/printk/printk.c:2697 [inline] console_unlock+0x591/0x7c0 kernel/printk/printk.c:2908 vprintk_emit+0x523/0x740 kernel/printk/printk.c:2303 _printk+0xd1/0x111 kernel/printk/printk.c:2328 bt_err+0x123/0x170 net/bluetooth/lib.c:251 hci_cmd_timeout+0xd9/0x1e0 net/bluetooth/hci_core.c:1457 process_one_work+0x917/0x1260 kernel/workqueue.c:2292 worker_thread+0xa47/0x1200 kernel/workqueue.c:2439 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 -> #0 ((console_sem).lock){-...}-{2:2}: check_prev_add kernel/locking/lockdep.c:3090 [inline] check_prevs_add kernel/locking/lockdep.c:3209 [inline] validate_chain+0x1661/0x5950 kernel/locking/lockdep.c:3825 __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5049 lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162 down_trylock+0x1c/0xa0 kernel/locking/semaphore.c:139 __down_trylock_console_sem+0x105/0x250 kernel/printk/printk.c:243 console_trylock kernel/printk/printk.c:2650 [inline] console_trylock_spinning kernel/printk/printk.c:1896 [inline] vprintk_emit+0x1ee/0x740 kernel/printk/printk.c:2302 _printk+0xd1/0x111 kernel/printk/printk.c:2328 fail_dump lib/fault-inject.c:45 [inline] should_fail_ex+0x387/0x4d0 lib/fault-inject.c:147 strncpy_from_user+0x32/0x360 lib/strncpy_from_user.c:118 strncpy_from_user_nofault+0x6c/0x130 mm/maccess.c:186 bpf_probe_read_user_str_common kernel/trace/bpf_trace.c:204 [inline] ____bpf_probe_read_user_str kernel/trace/bpf_trace.c:213 [inline] bpf_probe_read_user_str+0x26/0x70 kernel/trace/bpf_trace.c:210 bpf_prog_bc7c5c6b9645592f+0x35/0x37 bpf_dispatcher_nop_func include/linux/bpf.h:1000 [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:2284 [inline] bpf_trace_run4+0x253/0x470 kernel/trace/bpf_trace.c:2325 __traceiter_sched_switch+0x91/0xc0 include/trace/events/sched.h:222 trace_sched_switch include/trace/events/sched.h:222 [inline] __schedule+0x2128/0x4570 kernel/sched/core.c:6557 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6872 irqentry_exit+0x53/0x80 kernel/entry/common.c:439 asm_sysvec_reschedule_ipi+0x16/0x20 arch/x86/include/asm/idtentry.h:696 arch_atomic64_dec_and_test arch/x86/include/asm/atomic64_64.h:118 [inline] arch_atomic_long_dec_and_test include/linux/atomic/atomic-long.h:467 [inline] atomic_long_dec_and_test include/linux/atomic/atomic-instrumented.h:1814 [inline] fput+0x25/0x1b0 fs/file_table.c:371 fdput include/linux/file.h:46 [inline] fdput_pos include/linux/file.h:81 [inline] ksys_write+0x263/0x2c0 fs/read_write.c:640 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 other info that might help us debug this: Chain exists of: (console_sem).lock --> &p->pi_lock --> &rq->__lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&rq->__lock); lock(&p->pi_lock); lock(&rq->__lock); lock((console_sem).lock); *** DEADLOCK *** 2 locks held by syz.3.273/5559: #0: ffff8880b8e3a9d8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:537 #1: ffffffff8d32e6c0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #1: ffffffff8d32e6c0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #1: ffffffff8d32e6c0 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2283 [inline] #1: ffffffff8d32e6c0 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run4+0x16a/0x470 kernel/trace/bpf_trace.c:2325 stack backtrace: CPU: 0 PID: 5559 Comm: syz.3.273 Not tainted 6.1.131-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106 check_noncircular+0x2fa/0x3b0 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+0x1661/0x5950 kernel/locking/lockdep.c:3825 __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5049 lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162 down_trylock+0x1c/0xa0 kernel/locking/semaphore.c:139 __down_trylock_console_sem+0x105/0x250 kernel/printk/printk.c:243 console_trylock kernel/printk/printk.c:2650 [inline] console_trylock_spinning kernel/printk/printk.c:1896 [inline] vprintk_emit+0x1ee/0x740 kernel/printk/printk.c:2302 _printk+0xd1/0x111 kernel/printk/printk.c:2328 fail_dump lib/fault-inject.c:45 [inline] should_fail_ex+0x387/0x4d0 lib/fault-inject.c:147 strncpy_from_user+0x32/0x360 lib/strncpy_from_user.c:118 strncpy_from_user_nofault+0x6c/0x130 mm/maccess.c:186 bpf_probe_read_user_str_common kernel/trace/bpf_trace.c:204 [inline] ____bpf_probe_read_user_str kernel/trace/bpf_trace.c:213 [inline] bpf_probe_read_user_str+0x26/0x70 kernel/trace/bpf_trace.c:210 bpf_prog_bc7c5c6b9645592f+0x35/0x37 bpf_dispatcher_nop_func include/linux/bpf.h:1000 [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:2284 [inline] bpf_trace_run4+0x253/0x470 kernel/trace/bpf_trace.c:2325 __traceiter_sched_switch+0x91/0xc0 include/trace/events/sched.h:222 trace_sched_switch include/trace/events/sched.h:222 [inline] __schedule+0x2128/0x4570 kernel/sched/core.c:6557 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6872 irqentry_exit+0x53/0x80 kernel/entry/common.c:439 asm_sysvec_reschedule_ipi+0x16/0x20 arch/x86/include/asm/idtentry.h:696 RIP: 0010:arch_atomic64_dec_and_test arch/x86/include/asm/atomic64_64.h:118 [inline] RIP: 0010:arch_atomic_long_dec_and_test include/linux/atomic/atomic-long.h:467 [inline] RIP: 0010:atomic_long_dec_and_test include/linux/atomic/atomic-instrumented.h:1814 [inline] RIP: 0010:fput+0x25/0x1b0 fs/file_table.c:371 Code: 00 00 00 00 00 55 41 57 41 56 41 54 53 49 89 ff e8 80 42 99 ff 49 8d 7f 70 be 08 00 00 00 e8 52 a5 f0 ff 31 db f0 49 ff 4f 70 <40> 0f 94 c5 0f 94 c3 bf 02 00 00 00 89 de e8 b8 44 99 ff 31 ff 89 RSP: 0018:ffffc90005277e10 EFLAGS: 00000202 RAX: ffffffff81f16701 RBX: 0000000000000000 RCX: ffffffff81f1674e RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffff888067e5f470 RBP: ffffc90005277f20 R08: dffffc0000000000 R09: ffffed100cfcbe8f R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000001 R13: 1ffff92000a4efd0 R14: ffff888067e5f403 R15: ffff888067e5f400 fdput include/linux/file.h:46 [inline] fdput_pos include/linux/file.h:81 [inline] ksys_write+0x263/0x2c0 fs/read_write.c:640 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f3dacd8bc1f 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:00007f3dadb02030 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 000000000000000b RCX: 00007f3dacd8bc1f RDX: 0000000000000001 RSI: 00007f3dadb02090 RDI: 000000000000000b RBP: 00007f3dadb02090 R08: 0000000000000000 R09: 00007f3dadb01df7 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000001 R13: 0000000000000000 R14: 00007f3dacfa6160 R15: 00007fff0c0750e8 CPU: 0 PID: 5559 Comm: syz.3.273 Not tainted 6.1.131-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106 fail_dump lib/fault-inject.c:52 [inline] should_fail_ex+0x3a6/0x4d0 lib/fault-inject.c:147 strncpy_from_user+0x32/0x360 lib/strncpy_from_user.c:118 strncpy_from_user_nofault+0x6c/0x130 mm/maccess.c:186 bpf_probe_read_user_str_common kernel/trace/bpf_trace.c:204 [inline] ____bpf_probe_read_user_str kernel/trace/bpf_trace.c:213 [inline] bpf_probe_read_user_str+0x26/0x70 kernel/trace/bpf_trace.c:210 bpf_prog_bc7c5c6b9645592f+0x35/0x37 bpf_dispatcher_nop_func include/linux/bpf.h:1000 [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:2284 [inline] bpf_trace_run4+0x253/0x470 kernel/trace/bpf_trace.c:2325 __traceiter_sched_switch+0x91/0xc0 include/trace/events/sched.h:222 trace_sched_switch include/trace/events/sched.h:222 [inline] __schedule+0x2128/0x4570 kernel/sched/core.c:6557 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6872 irqentry_exit+0x53/0x80 kernel/entry/common.c:439 asm_sysvec_reschedule_ipi+0x16/0x20 arch/x86/include/asm/idtentry.h:696 RIP: 0010:arch_atomic64_dec_and_test arch/x86/include/asm/atomic64_64.h:118 [inline] RIP: 0010:arch_atomic_long_dec_and_test include/linux/atomic/atomic-long.h:467 [inline] RIP: 0010:atomic_long_dec_and_test include/linux/atomic/atomic-instrumented.h:1814 [inline] RIP: 0010:fput+0x25/0x1b0 fs/file_table.c:371 Code: 00 00 00 00 00 55 41 57 41 56 41 54 53 49 89 ff e8 80 42 99 ff 49 8d 7f 70 be 08 00 00 00 e8 52 a5 f0 ff 31 db f0 49 ff 4f 70 <40> 0f 94 c5 0f 94 c3 bf 02 00 00 00 89 de e8 b8 44 99 ff 31 ff 89 RSP: 0018:ffffc90005277e10 EFLAGS: 00000202 RAX: ffffffff81f16701 RBX: 0000000000000000 RCX: ffffffff81f1674e RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffff888067e5f470 RBP: ffffc90005277f20 R08: dffffc0000000000 R09: ffffed100cfcbe8f R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000001 R13: 1ffff92000a4efd0 R14: ffff888067e5f403 R15: ffff888067e5f400 fdput include/linux/file.h:46 [inline] fdput_pos include/linux/file.h:81 [inline] ksys_write+0x263/0x2c0 fs/read_write.c:640 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f3dacd8bc1f 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:00007f3dadb02030 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 000000000000000b RCX: 00007f3dacd8bc1f RDX: 0000000000000001 RSI: 00007f3dadb02090 RDI: 000000000000000b RBP: 00007f3dadb02090 R08: 0000000000000000 R09: 00007f3dadb01df7 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000001 R13: 0000000000000000 R14: 00007f3dacfa6160 R15: 00007fff0c0750e8 ---------------- Code disassembly (best guess): 0: 00 00 add %al,(%rax) 2: 00 00 add %al,(%rax) 4: 00 55 41 add %dl,0x41(%rbp) 7: 57 push %rdi 8: 41 56 push %r14 a: 41 54 push %r12 c: 53 push %rbx d: 49 89 ff mov %rdi,%r15 10: e8 80 42 99 ff call 0xff994295 15: 49 8d 7f 70 lea 0x70(%r15),%rdi 19: be 08 00 00 00 mov $0x8,%esi 1e: e8 52 a5 f0 ff call 0xfff0a575 23: 31 db xor %ebx,%ebx 25: f0 49 ff 4f 70 lock decq 0x70(%r15) * 2a: 40 0f 94 c5 sete %bpl <-- trapping instruction 2e: 0f 94 c3 sete %bl 31: bf 02 00 00 00 mov $0x2,%edi 36: 89 de mov %ebx,%esi 38: e8 b8 44 99 ff call 0xff9944f5 3d: 31 ff xor %edi,%edi 3f: 89 .byte 0x89