FAULT_INJECTION: forcing a failure.
name fail_usercopy, interval 1, probability 0, space 0, times 0
======================================================
WARNING: possible circular locking dependency detected
6.1.119-syzkaller #0 Not tainted
------------------------------------------------------
syz.3.185/5172 is trying to acquire lock:
ffffffff8d2070f8 ((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:11877
       sched_cgroup_fork+0x374/0x400 kernel/sched/core.c:4682
       copy_process+0x2442/0x4060 kernel/fork.c:2383
       kernel_clone+0x222/0x920 kernel/fork.c:2681
       user_mode_thread+0x12e/0x190 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/0x12e0 kernel/sched/core.c:4108
       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
       __ext4_msg+0x2d3/0x2e0 fs/ext4/super.c:939
       ext4_fill_super+0x3135/0x8b50 fs/ext4/super.c:5680
       get_tree_bdev+0x3fe/0x620 fs/super.c:1366
       vfs_get_tree+0x88/0x270 fs/super.c:1573
       do_new_mount+0x2ba/0xb40 fs/namespace.c:3056
       do_mount fs/namespace.c:3399 [inline]
       __do_sys_mount fs/namespace.c:3607 [inline]
       __se_sys_mount+0x2d5/0x3c0 fs/namespace.c:3584
       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

-> #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:989 [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:2271 [inline]
       bpf_trace_run4+0x253/0x470 kernel/trace/bpf_trace.c:2312
       __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:6555
       preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6870
       irqentry_exit+0x53/0x80 kernel/entry/common.c:439
       asm_sysvec_reschedule_ipi+0x16/0x20 arch/x86/include/asm/idtentry.h:696
       __mutex_unlock_slowpath+0x1c0/0x750 kernel/locking/mutex.c:919
       fdput_pos include/linux/file.h:80 [inline]
       ksys_write+0x23a/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.3.185/5172:
 #0: ffff8880b8e3a9d8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:537
 #1: ffffffff8d32af40 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
 #1: ffffffff8d32af40 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
 #1: ffffffff8d32af40 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2270 [inline]
 #1: ffffffff8d32af40 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run4+0x16a/0x470 kernel/trace/bpf_trace.c:2312

stack backtrace:
CPU: 0 PID: 5172 Comm: syz.3.185 Not tainted 6.1.119-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
 <TASK>
 __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:989 [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:2271 [inline]
 bpf_trace_run4+0x253/0x470 kernel/trace/bpf_trace.c:2312
 __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:6555
 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6870
 irqentry_exit+0x53/0x80 kernel/entry/common.c:439
 asm_sysvec_reschedule_ipi+0x16/0x20 arch/x86/include/asm/idtentry.h:696
RIP: 0010:__mutex_unlock_slowpath+0x1c0/0x750 kernel/locking/mutex.c:919
Code: 85 77 01 00 00 83 3d ae 58 7a 0c 00 75 22 43 80 3c 2f 00 74 0d 48 8d bc 24 a0 00 00 00 e8 48 4c 27 f7 f6 84 24 a0 00 00 00 04 <0f> 85 da 00 00 00 43 80 3c 2f 00 74 0d 48 8d bc 24 a0 00 00 00 e8
RSP: 0018:ffffc900034c7d20 EFLAGS: 00000246
RAX: 0000000000000004 RBX: ffff88802b421dc0 RCX: ffffffff97353103
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff888073696a80
RBP: ffffc900034c7e30 R08: dffffc0000000000 R09: ffffed100e6d2d51
R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffffffff2e6a62c
R13: dffffc0000000000 R14: ffff888073696a80 R15: 1ffff92000698fb8
 fdput_pos include/linux/file.h:80 [inline]
 ksys_write+0x23a/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: 0033:0x7fd4a577f2ff
Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 f9 8d 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 8e 02 00 48
RSP: 002b:00007fd4a65e6050 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000006 RCX: 00007fd4a577f2ff
RDX: 0000000000000001 RSI: 00007fd4a65e60a0 RDI: 0000000000000006
RBP: 00007fd4a65e60a0 R08: 0000000000000000 R09: 00007fd4a65e5e17
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000001
R13: 0000000000000000 R14: 00007fd4a5946160 R15: 00007ffd14ea89f8
 </TASK>
CPU: 0 PID: 5172 Comm: syz.3.185 Not tainted 6.1.119-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
 <TASK>
 __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:989 [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:2271 [inline]
 bpf_trace_run4+0x253/0x470 kernel/trace/bpf_trace.c:2312
 __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:6555
 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6870
 irqentry_exit+0x53/0x80 kernel/entry/common.c:439
 asm_sysvec_reschedule_ipi+0x16/0x20 arch/x86/include/asm/idtentry.h:696
RIP: 0010:__mutex_unlock_slowpath+0x1c0/0x750 kernel/locking/mutex.c:919
Code: 85 77 01 00 00 83 3d ae 58 7a 0c 00 75 22 43 80 3c 2f 00 74 0d 48 8d bc 24 a0 00 00 00 e8 48 4c 27 f7 f6 84 24 a0 00 00 00 04 <0f> 85 da 00 00 00 43 80 3c 2f 00 74 0d 48 8d bc 24 a0 00 00 00 e8
RSP: 0018:ffffc900034c7d20 EFLAGS: 00000246
RAX: 0000000000000004 RBX: ffff88802b421dc0 RCX: ffffffff97353103
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff888073696a80
RBP: ffffc900034c7e30 R08: dffffc0000000000 R09: ffffed100e6d2d51
R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffffffff2e6a62c
R13: dffffc0000000000 R14: ffff888073696a80 R15: 1ffff92000698fb8
 fdput_pos include/linux/file.h:80 [inline]
 ksys_write+0x23a/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: 0033:0x7fd4a577f2ff
Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 f9 8d 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 8e 02 00 48
RSP: 002b:00007fd4a65e6050 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000006 RCX: 00007fd4a577f2ff
RDX: 0000000000000001 RSI: 00007fd4a65e60a0 RDI: 0000000000000006
RBP: 00007fd4a65e60a0 R08: 0000000000000000 R09: 00007fd4a65e5e17
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000001
R13: 0000000000000000 R14: 00007fd4a5946160 R15: 00007ffd14ea89f8
 </TASK>
----------------
Code disassembly (best guess):
   0:	85 77 01             	test   %esi,0x1(%rdi)
   3:	00 00                	add    %al,(%rax)
   5:	83 3d ae 58 7a 0c 00 	cmpl   $0x0,0xc7a58ae(%rip)        # 0xc7a58ba
   c:	75 22                	jne    0x30
   e:	43 80 3c 2f 00       	cmpb   $0x0,(%r15,%r13,1)
  13:	74 0d                	je     0x22
  15:	48 8d bc 24 a0 00 00 	lea    0xa0(%rsp),%rdi
  1c:	00
  1d:	e8 48 4c 27 f7       	call   0xf7274c6a
  22:	f6 84 24 a0 00 00 00 	testb  $0x4,0xa0(%rsp)
  29:	04
* 2a:	0f 85 da 00 00 00    	jne    0x10a <-- trapping instruction
  30:	43 80 3c 2f 00       	cmpb   $0x0,(%r15,%r13,1)
  35:	74 0d                	je     0x44
  37:	48 8d bc 24 a0 00 00 	lea    0xa0(%rsp),%rdi
  3e:	00
  3f:	e8                   	.byte 0xe8