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-syzkaller-g9aa8fe29f624 #0 Not tainted
------------------------------------------------------
syz.5.496/8192 is trying to acquire lock:
ffffffff8ea14c58 ((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:898
       cgroup_post_fork+0x284/0x8b0 kernel/cgroup/cgroup.c:6695
       copy_process+0x398a/0x3cf0 kernel/fork.c:2629
       kernel_clone+0x226/0x8e0 kernel/fork.c:2815
       user_mode_thread+0x144/0x1c0 kernel/fork.c:2893
       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:551 [inline]
       try_to_wake_up+0xc2/0x1470 kernel/sched/core.c:4214
       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
       vprintk_emit+0x730/0xa10 kernel/printk/printk.c:2432
       dev_vprintk_emit+0x341/0x400 drivers/base/core.c:4890
       dev_printk_emit+0xdd/0x120 drivers/base/core.c:4901
       _dev_warn+0x122/0x170 drivers/base/core.c:4957
       firmware_fallback_sysfs+0x4cf/0x9e0 drivers/base/firmware_loader/fallback.c:233
       _request_firmware+0xe44/0x1430 drivers/base/firmware_loader/main.c:941
       request_firmware_work_func+0x12a/0x280 drivers/base/firmware_loader/main.c:1194
       process_one_work kernel/workqueue.c:3236 [inline]
       process_scheduled_works+0xabe/0x18e0 kernel/workqueue.c:3317
       worker_thread+0x870/0xd30 kernel/workqueue.c:3398
       kthread+0x7a9/0x920 kernel/kthread.c:464
       ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

-> #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+0x36/0x270 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_c1796171ffc7efef+0x3e/0x40
       bpf_dispatcher_nop_func include/linux/bpf.h:1306 [inline]
       __bpf_prog_run include/linux/filter.h:718 [inline]
       bpf_prog_run include/linux/filter.h:725 [inline]
       __bpf_trace_run kernel/trace/bpf_trace.c:2377 [inline]
       bpf_trace_run4+0x334/0x590 kernel/trace/bpf_trace.c:2420
       __bpf_trace_sched_switch+0x294/0x3d0 include/trace/events/sched.h:222
       __traceiter_sched_switch+0x98/0xd0 include/trace/events/sched.h:222
       __do_trace_sched_switch include/trace/events/sched.h:222 [inline]
       trace_sched_switch include/trace/events/sched.h:222 [inline]
       __schedule+0x23ad/0x4c90 kernel/sched/core.c:6762
       preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:7087
       irqentry_exit+0x5e/0x90 kernel/entry/common.c:354
       asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
       should_resched arch/x86/include/asm/preempt.h:103 [inline]
       __local_bh_enable_ip+0x170/0x200 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:4406
       __sys_bpf+0x4da/0x890 kernel/bpf/syscall.c:5831
       __do_sys_bpf kernel/bpf/syscall.c:5920 [inline]
       __se_sys_bpf kernel/bpf/syscall.c:5918 [inline]
       __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5918
       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.5.496/8192:
 #0: ffffffff8eb39020 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
 #0: ffffffff8eb39020 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffffffff8eb39020 (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: ffffffff8eb39020 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
 #2: ffffffff8eb39020 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #2: ffffffff8eb39020 (rcu_read_lock){....}-{1:3}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2376 [inline]
 #2: ffffffff8eb39020 (rcu_read_lock){....}-{1:3}, at: bpf_trace_run4+0x244/0x590 kernel/trace/bpf_trace.c:2420

stack backtrace:
CPU: 0 UID: 0 PID: 8192 Comm: syz.5.496 Not tainted 6.14.0-rc3-syzkaller-g9aa8fe29f624 #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+0x36/0x270 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_c1796171ffc7efef+0x3e/0x40
 bpf_dispatcher_nop_func include/linux/bpf.h:1306 [inline]
 __bpf_prog_run include/linux/filter.h:718 [inline]
 bpf_prog_run include/linux/filter.h:725 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:2377 [inline]
 bpf_trace_run4+0x334/0x590 kernel/trace/bpf_trace.c:2420
 __bpf_trace_sched_switch+0x294/0x3d0 include/trace/events/sched.h:222
 __traceiter_sched_switch+0x98/0xd0 include/trace/events/sched.h:222
 __do_trace_sched_switch include/trace/events/sched.h:222 [inline]
 trace_sched_switch include/trace/events/sched.h:222 [inline]
 __schedule+0x23ad/0x4c90 kernel/sched/core.c:6762
 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:7087
 irqentry_exit+0x5e/0x90 kernel/entry/common.c:354
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:should_resched arch/x86/include/asm/preempt.h:103 [inline]
RIP: 0010:__local_bh_enable_ip+0x170/0x200 kernel/softirq.c:396
Code: 8c e8 04 b4 85 0a 65 66 8b 05 14 8e 80 7e 66 85 c0 75 5d bf 01 00 00 00 e8 4d 24 0c 00 e8 08 4a 46 00 fb 65 8b 05 d8 8d 80 7e <85> c0 75 05 e8 e7 f5 a6 ff 48 c7 44 24 20 0e 36 e0 45 49 c7 04 1c
RSP: 0018:ffffc9000c6f7840 EFLAGS: 00000286
RAX: 0000000080000000 RBX: 1ffff920018def0c RCX: ffffffff9a653903
RDX: dffffc0000000000 RSI: ffffffff8c2aa4a0 RDI: ffffffff8c810bc0
RBP: ffffc9000c6f78f0 R08: ffffffff903d0577 R09: 1ffffffff207a0ae
R10: dffffc0000000000 R11: fffffbfff207a0af R12: dffffc0000000000
R13: 1ffff920018def10 R14: ffffc9000c6f7880 R15: 0000000000000200
 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:4406
 __sys_bpf+0x4da/0x890 kernel/bpf/syscall.c:5831
 __do_sys_bpf kernel/bpf/syscall.c:5920 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:5918 [inline]
 __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5918
 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: 0033:0x7f0025b8d169
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f0026a4c038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007f0025da5fa0 RCX: 00007f0025b8d169
RDX: 0000000000000048 RSI: 0000200000000040 RDI: 000000000000000a
RBP: 00007f0026a4c090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000002
R13: 0000000000000000 R14: 00007f0025da5fa0 R15: 00007fff22e5fe18
 </TASK>
CPU: 0 UID: 0 PID: 8192 Comm: syz.5.496 Not tainted 6.14.0-rc3-syzkaller-g9aa8fe29f624 #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+0x36/0x270 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_c1796171ffc7efef+0x3e/0x40
 bpf_dispatcher_nop_func include/linux/bpf.h:1306 [inline]
 __bpf_prog_run include/linux/filter.h:718 [inline]
 bpf_prog_run include/linux/filter.h:725 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:2377 [inline]
 bpf_trace_run4+0x334/0x590 kernel/trace/bpf_trace.c:2420
 __bpf_trace_sched_switch+0x294/0x3d0 include/trace/events/sched.h:222
 __traceiter_sched_switch+0x98/0xd0 include/trace/events/sched.h:222
 __do_trace_sched_switch include/trace/events/sched.h:222 [inline]
 trace_sched_switch include/trace/events/sched.h:222 [inline]
 __schedule+0x23ad/0x4c90 kernel/sched/core.c:6762
 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:7087
 irqentry_exit+0x5e/0x90 kernel/entry/common.c:354
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:should_resched arch/x86/include/asm/preempt.h:103 [inline]
RIP: 0010:__local_bh_enable_ip+0x170/0x200 kernel/softirq.c:396
Code: 8c e8 04 b4 85 0a 65 66 8b 05 14 8e 80 7e 66 85 c0 75 5d bf 01 00 00 00 e8 4d 24 0c 00 e8 08 4a 46 00 fb 65 8b 05 d8 8d 80 7e <85> c0 75 05 e8 e7 f5 a6 ff 48 c7 44 24 20 0e 36 e0 45 49 c7 04 1c
RSP: 0018:ffffc9000c6f7840 EFLAGS: 00000286
RAX: 0000000080000000 RBX: 1ffff920018def0c RCX: ffffffff9a653903
RDX: dffffc0000000000 RSI: ffffffff8c2aa4a0 RDI: ffffffff8c810bc0
RBP: ffffc9000c6f78f0 R08: ffffffff903d0577 R09: 1ffffffff207a0ae
R10: dffffc0000000000 R11: fffffbfff207a0af R12: dffffc0000000000
R13: 1ffff920018def10 R14: ffffc9000c6f7880 R15: 0000000000000200
 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:4406
 __sys_bpf+0x4da/0x890 kernel/bpf/syscall.c:5831
 __do_sys_bpf kernel/bpf/syscall.c:5920 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:5918 [inline]
 __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5918
 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: 0033:0x7f0025b8d169
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f0026a4c038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007f0025da5fa0 RCX: 00007f0025b8d169
RDX: 0000000000000048 RSI: 0000200000000040 RDI: 000000000000000a
RBP: 00007f0026a4c090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000002
R13: 0000000000000000 R14: 00007f0025da5fa0 R15: 00007fff22e5fe18
 </TASK>
----------------
Code disassembly (best guess):
   0:	8c e8                	mov    %gs,%eax
   2:	04 b4                	add    $0xb4,%al
   4:	85 0a                	test   %ecx,(%rdx)
   6:	65 66 8b 05 14 8e 80 	mov    %gs:0x7e808e14(%rip),%ax        # 0x7e808e22
   d:	7e
   e:	66 85 c0             	test   %ax,%ax
  11:	75 5d                	jne    0x70
  13:	bf 01 00 00 00       	mov    $0x1,%edi
  18:	e8 4d 24 0c 00       	call   0xc246a
  1d:	e8 08 4a 46 00       	call   0x464a2a
  22:	fb                   	sti
  23:	65 8b 05 d8 8d 80 7e 	mov    %gs:0x7e808dd8(%rip),%eax        # 0x7e808e02
* 2a:	85 c0                	test   %eax,%eax <-- trapping instruction
  2c:	75 05                	jne    0x33
  2e:	e8 e7 f5 a6 ff       	call   0xffa6f61a
  33:	48 c7 44 24 20 0e 36 	movq   $0x45e0360e,0x20(%rsp)
  3a:	e0 45
  3c:	49                   	rex.WB
  3d:	c7                   	.byte 0xc7
  3e:	04 1c                	add    $0x1c,%al