FAULT_INJECTION: forcing a failure.
name fail_usercopy, interval 1, probability 0, space 0, times 0
======================================================
WARNING: possible circular locking dependency detected
6.14.0-rc3-next-20250218-syzkaller #0 Not tainted
------------------------------------------------------
syz.3.637/9512 is trying to acquire lock:
ffffffff8ea16ff8 ((console_sem).lock){-.-.}-{2:2}, at: down_trylock+0x20/0xa0 kernel/locking/semaphore.c:139

but task is already holding lock:
ffff8880b863e958 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:598

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #2 (&rq->__lock){-.-.}-{2:2}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851
       _raw_spin_lock_nested+0x31/0x40 kernel/locking/spinlock.c:378
       raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:598
       raw_spin_rq_lock kernel/sched/sched.h:1521 [inline]
       task_rq_lock+0xc6/0x360 kernel/sched/core.c:700
       cgroup_move_task+0x9b/0x5a0 kernel/sched/psi.c:1161
       css_set_move_task+0x72e/0x950 kernel/cgroup/cgroup.c:911
       cgroup_post_fork+0x284/0x8b0 kernel/cgroup/cgroup.c:6709
       copy_process+0x398a/0x3cf0 kernel/fork.c:2612
       kernel_clone+0x226/0x8e0 kernel/fork.c:2798
       user_mode_thread+0x144/0x1c0 kernel/fork.c:2876
       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:515
       x86_64_start_kernel+0x66/0x70 arch/x86/kernel/head64.c:496
       common_startup_64+0x13e/0x147

-> #1 (&p->pi_lock){-.-.}-{2:2}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162
       class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:557 [inline]
       try_to_wake_up+0xc2/0x1470 kernel/sched/core.c:4209
       up+0x72/0x90 kernel/locking/semaphore.c:191
       __up_console_sem kernel/printk/printk.c:343 [inline]
       __console_unlock+0x123/0x1f0 kernel/printk/printk.c:2869
       __console_flush_and_unlock kernel/printk/printk.c:3271 [inline]
       console_unlock+0x18f/0x3b0 kernel/printk/printk.c:3309
       tioclinux+0x447/0x490 drivers/tty/vt/vt.c:3407
       vt_ioctl+0x9db/0x2020 drivers/tty/vt/vt_ioctl.c:761
       tty_ioctl+0x90f/0xdc0 drivers/tty/tty_io.c:2802
       vfs_ioctl fs/ioctl.c:51 [inline]
       __do_sys_ioctl fs/ioctl.c:906 [inline]
       __se_sys_ioctl+0xf1/0x160 fs/ioctl.c:892
       do_syscall_x64 arch/x86/entry/common.c:52 [inline]
       do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #0 ((console_sem).lock){-.-.}-{2:2}:
       check_prev_add kernel/locking/lockdep.c:3163 [inline]
       check_prevs_add kernel/locking/lockdep.c:3282 [inline]
       validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3906
       __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5228
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162
       down_trylock+0x20/0xa0 kernel/locking/semaphore.c:139
       __down_trylock_console_sem+0x109/0x250 kernel/printk/printk.c:326
       console_trylock kernel/printk/printk.c:2852 [inline]
       console_trylock_spinning kernel/printk/printk.c:2009 [inline]
       vprintk_emit+0x3d7/0xa10 kernel/printk/printk.c:2431
       _printk+0xd5/0x120 kernel/printk/printk.c:2457
       fail_dump lib/fault-inject.c:66 [inline]
       should_fail_ex+0x3eb/0x550 lib/fault-inject.c:174
       strncpy_from_user+0x36/0x280 lib/strncpy_from_user.c:118
       strncpy_from_user_nofault+0x71/0x140 mm/maccess.c:193
       bpf_probe_read_user_str_common kernel/trace/bpf_trace.c:215 [inline]
       ____bpf_probe_read_compat_str kernel/trace/bpf_trace.c:310 [inline]
       bpf_probe_read_compat_str+0xe9/0x180 kernel/trace/bpf_trace.c:306
       bpf_prog_83101f93da67a838+0x46/0x48
       bpf_dispatcher_nop_func include/linux/bpf.h:1290 [inline]
       __bpf_prog_run include/linux/filter.h:701 [inline]
       bpf_prog_run include/linux/filter.h:708 [inline]
       __bpf_trace_run kernel/trace/bpf_trace.c:2357 [inline]
       bpf_trace_run2+0x2ec/0x540 kernel/trace/bpf_trace.c:2398
       __bpf_trace_tlb_flush+0x174/0x230 include/trace/events/tlb.h:38
       __do_trace_tlb_flush include/trace/events/tlb.h:38 [inline]
       trace_tlb_flush+0x11c/0x140 include/trace/events/tlb.h:38
       switch_mm_irqs_off+0x77e/0xa70
       context_switch kernel/sched/core.c:5357 [inline]
       __schedule+0x1194/0x4c90 kernel/sched/core.c:6760
       preempt_schedule_common+0x84/0xd0 kernel/sched/core.c:6939
       preempt_schedule+0xe1/0xf0 kernel/sched/core.c:6963
       preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
       __local_bh_enable_ip+0x179/0x200 kernel/softirq.c:396
       local_bh_enable include/linux/bottom_half.h:33 [inline]
       bpf_test_run+0x56b/0xa90 net/bpf/test_run.c:437
       bpf_prog_test_run_skb+0xcaa/0x1830 net/bpf/test_run.c:1093
       bpf_prog_test_run+0x2e4/0x360 kernel/bpf/syscall.c:4415
       __sys_bpf+0x496/0x840 kernel/bpf/syscall.c:5821
       __do_sys_bpf kernel/bpf/syscall.c:5910 [inline]
       __se_sys_bpf kernel/bpf/syscall.c:5908 [inline]
       __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5908
       do_syscall_x64 arch/x86/entry/common.c:52 [inline]
       do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

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 ***

3 locks held by syz.3.637/9512:
 #0: ffffffff8eb3b3a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8eb3b3a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
 #0: ffffffff8eb3b3a0 (rcu_read_lock){....}-{1:3}, at: bpf_test_timer_enter+0x19/0x140 net/bpf/test_run.c:40
 #1: ffff8880b863e958 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:598
 #2: ffffffff8eb3b3a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #2: ffffffff8eb3b3a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
 #2: ffffffff8eb3b3a0 (rcu_read_lock){....}-{1:3}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2356 [inline]
 #2: ffffffff8eb3b3a0 (rcu_read_lock){....}-{1:3}, at: bpf_trace_run2+0x1fc/0x540 kernel/trace/bpf_trace.c:2398

stack backtrace:
CPU: 0 UID: 0 PID: 9512 Comm: syz.3.637 Not tainted 6.14.0-rc3-next-20250218-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 print_circular_bug+0x13a/0x1b0 kernel/locking/lockdep.c:2076
 check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2208
 check_prev_add kernel/locking/lockdep.c:3163 [inline]
 check_prevs_add kernel/locking/lockdep.c:3282 [inline]
 validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3906
 __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5228
 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162
 down_trylock+0x20/0xa0 kernel/locking/semaphore.c:139
 __down_trylock_console_sem+0x109/0x250 kernel/printk/printk.c:326
 console_trylock kernel/printk/printk.c:2852 [inline]
 console_trylock_spinning kernel/printk/printk.c:2009 [inline]
 vprintk_emit+0x3d7/0xa10 kernel/printk/printk.c:2431
 _printk+0xd5/0x120 kernel/printk/printk.c:2457
 fail_dump lib/fault-inject.c:66 [inline]
 should_fail_ex+0x3eb/0x550 lib/fault-inject.c:174
 strncpy_from_user+0x36/0x280 lib/strncpy_from_user.c:118
 strncpy_from_user_nofault+0x71/0x140 mm/maccess.c:193
 bpf_probe_read_user_str_common kernel/trace/bpf_trace.c:215 [inline]
 ____bpf_probe_read_compat_str kernel/trace/bpf_trace.c:310 [inline]
 bpf_probe_read_compat_str+0xe9/0x180 kernel/trace/bpf_trace.c:306
 bpf_prog_83101f93da67a838+0x46/0x48
 bpf_dispatcher_nop_func include/linux/bpf.h:1290 [inline]
 __bpf_prog_run include/linux/filter.h:701 [inline]
 bpf_prog_run include/linux/filter.h:708 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:2357 [inline]
 bpf_trace_run2+0x2ec/0x540 kernel/trace/bpf_trace.c:2398
 __bpf_trace_tlb_flush+0x174/0x230 include/trace/events/tlb.h:38
 __do_trace_tlb_flush include/trace/events/tlb.h:38 [inline]
 trace_tlb_flush+0x11c/0x140 include/trace/events/tlb.h:38
 switch_mm_irqs_off+0x77e/0xa70
 context_switch kernel/sched/core.c:5357 [inline]
 __schedule+0x1194/0x4c90 kernel/sched/core.c:6760
 preempt_schedule_common+0x84/0xd0 kernel/sched/core.c:6939
 preempt_schedule+0xe1/0xf0 kernel/sched/core.c:6963
 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
 __local_bh_enable_ip+0x179/0x200 kernel/softirq.c:396
 local_bh_enable include/linux/bottom_half.h:33 [inline]
 bpf_test_run+0x56b/0xa90 net/bpf/test_run.c:437
 bpf_prog_test_run_skb+0xcaa/0x1830 net/bpf/test_run.c:1093
 bpf_prog_test_run+0x2e4/0x360 kernel/bpf/syscall.c:4415
 __sys_bpf+0x496/0x840 kernel/bpf/syscall.c:5821
 __do_sys_bpf kernel/bpf/syscall.c:5910 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:5908 [inline]
 __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5908
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f19fd78d169
Code: Unable to access opcode bytes at 0x7f19fd78d13f.
RSP: 002b:00007f19fe55d038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007f19fd9a5fa0 RCX: 00007f19fd78d169
RDX: 0000000000000050 RSI: 00004000000004c0 RDI: 000000000000000a
RBP: 00007f19fe55d090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 0000000000000000 R14: 00007f19fd9a5fa0 R15: 00007ffd77c19bd8
 </TASK>
CPU: 0 UID: 0 PID: 9512 Comm: syz.3.637 Not tainted 6.14.0-rc3-next-20250218-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 fail_dump lib/fault-inject.c:73 [inline]
 should_fail_ex+0x40a/0x550 lib/fault-inject.c:174
 strncpy_from_user+0x36/0x280 lib/strncpy_from_user.c:118
 strncpy_from_user_nofault+0x71/0x140 mm/maccess.c:193
 bpf_probe_read_user_str_common kernel/trace/bpf_trace.c:215 [inline]
 ____bpf_probe_read_compat_str kernel/trace/bpf_trace.c:310 [inline]
 bpf_probe_read_compat_str+0xe9/0x180 kernel/trace/bpf_trace.c:306
 bpf_prog_83101f93da67a838+0x46/0x48
 bpf_dispatcher_nop_func include/linux/bpf.h:1290 [inline]
 __bpf_prog_run include/linux/filter.h:701 [inline]
 bpf_prog_run include/linux/filter.h:708 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:2357 [inline]
 bpf_trace_run2+0x2ec/0x540 kernel/trace/bpf_trace.c:2398
 __bpf_trace_tlb_flush+0x174/0x230 include/trace/events/tlb.h:38
 __do_trace_tlb_flush include/trace/events/tlb.h:38 [inline]
 trace_tlb_flush+0x11c/0x140 include/trace/events/tlb.h:38
 switch_mm_irqs_off+0x77e/0xa70
 context_switch kernel/sched/core.c:5357 [inline]
 __schedule+0x1194/0x4c90 kernel/sched/core.c:6760
 preempt_schedule_common+0x84/0xd0 kernel/sched/core.c:6939
 preempt_schedule+0xe1/0xf0 kernel/sched/core.c:6963
 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
 __local_bh_enable_ip+0x179/0x200 kernel/softirq.c:396
 local_bh_enable include/linux/bottom_half.h:33 [inline]
 bpf_test_run+0x56b/0xa90 net/bpf/test_run.c:437
 bpf_prog_test_run_skb+0xcaa/0x1830 net/bpf/test_run.c:1093
 bpf_prog_test_run+0x2e4/0x360 kernel/bpf/syscall.c:4415
 __sys_bpf+0x496/0x840 kernel/bpf/syscall.c:5821
 __do_sys_bpf kernel/bpf/syscall.c:5910 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:5908 [inline]
 __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5908
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f19fd78d169
Code: Unable to access opcode bytes at 0x7f19fd78d13f.
RSP: 002b:00007f19fe55d038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007f19fd9a5fa0 RCX: 00007f19fd78d169
RDX: 0000000000000050 RSI: 00004000000004c0 RDI: 000000000000000a
RBP: 00007f19fe55d090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 0000000000000000 R14: 00007f19fd9a5fa0 R15: 00007ffd77c19bd8
 </TASK>