FAULT_INJECTION: forcing a failure.
name fail_usercopy, interval 1, probability 0, space 0, times 0
======================================================
WARNING: possible circular locking dependency detected
6.11.0-rc6-syzkaller-00326-gd1f2d51b711a #0 Not tainted
------------------------------------------------------
syz.1.76/5659 is trying to acquire lock:
ffffffff8dda8018 ((console_sem).lock){-...}-{2:2}, at: down_trylock+0x12/0x70 kernel/locking/semaphore.c:139

but task is already holding lock:
ffff88806a63edd8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:568 [inline]
ffff88806a63edd8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x7e/0x130 kernel/sched/core.c:553

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #2 (&rq->__lock){-.-.}-{2:2}:
       _raw_spin_lock_nested+0x31/0x40 kernel/locking/spinlock.c:378
       raw_spin_rq_lock_nested+0x29/0x130 kernel/sched/core.c:560
       raw_spin_rq_lock kernel/sched/sched.h:1415 [inline]
       rq_lock kernel/sched/sched.h:1714 [inline]
       task_fork_fair+0x73/0x250 kernel/sched/fair.c:12710
       sched_cgroup_fork+0x3cf/0x510 kernel/sched/core.c:4633
       copy_process+0x43a1/0x8de0 kernel/fork.c:2483
       kernel_clone+0xfd/0x960 kernel/fork.c:2781
       user_mode_thread+0xb4/0xf0 kernel/fork.c:2859
       rest_init+0x23/0x2b0 init/main.c:712
       start_kernel+0x3df/0x4c0 init/main.c:1103
       x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:507
       x86_64_start_kernel+0xb2/0xc0 arch/x86/kernel/head64.c:488
       common_startup_64+0x13e/0x148

-> #1 (&p->pi_lock){-.-.}-{2:2}:
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162
       class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:551 [inline]
       try_to_wake_up+0x9a/0x13e0 kernel/sched/core.c:4051
       up+0x79/0xb0 kernel/locking/semaphore.c:191
       __up_console_sem kernel/printk/printk.c:340 [inline]
       __console_unlock kernel/printk/printk.c:2801 [inline]
       console_unlock+0x23e/0x290 kernel/printk/printk.c:3120
       vga_remove_vgacon drivers/pci/vgaarb.c:186 [inline]
       vga_remove_vgacon+0x90/0xd0 drivers/pci/vgaarb.c:167
       __aperture_remove_legacy_vga_devices drivers/video/aperture.c:331 [inline]
       aperture_remove_conflicting_pci_devices+0x16a/0x1e0 drivers/video/aperture.c:369
       virtio_gpu_pci_quirk drivers/gpu/drm/virtio/virtgpu_drv.c:61 [inline]
       virtio_gpu_probe+0x408/0x4e0 drivers/gpu/drm/virtio/virtgpu_drv.c:92
       virtio_dev_probe+0x586/0x8a0 drivers/virtio/virtio.c:308
       call_driver_probe drivers/base/dd.c:578 [inline]
       really_probe+0x23e/0xa90 drivers/base/dd.c:657
       __driver_probe_device+0x1de/0x440 drivers/base/dd.c:799
       driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:829
       __driver_attach+0x283/0x580 drivers/base/dd.c:1215
       bus_for_each_dev+0x13c/0x1d0 drivers/base/bus.c:368
       bus_add_driver+0x2e9/0x690 drivers/base/bus.c:673
       driver_register+0x15c/0x4b0 drivers/base/driver.c:246
       do_one_initcall+0x128/0x700 init/main.c:1267
       do_initcall_level init/main.c:1329 [inline]
       do_initcalls init/main.c:1345 [inline]
       do_basic_setup init/main.c:1364 [inline]
       kernel_init_freeable+0x69d/0xca0 init/main.c:1578
       kernel_init+0x1c/0x2b0 init/main.c:1467
       ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
       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:3133 [inline]
       check_prevs_add kernel/locking/lockdep.c:3252 [inline]
       validate_chain kernel/locking/lockdep.c:3868 [inline]
       __lock_acquire+0x24ed/0x3cb0 kernel/locking/lockdep.c:5142
       lock_acquire kernel/locking/lockdep.c:5759 [inline]
       lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5724
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162
       down_trylock+0x12/0x70 kernel/locking/semaphore.c:139
       __down_trylock_console_sem+0x40/0x140 kernel/printk/printk.c:323
       console_trylock kernel/printk/printk.c:2754 [inline]
       console_trylock_spinning kernel/printk/printk.c:1958 [inline]
       vprintk_emit+0x3d3/0x600 kernel/printk/printk.c:2347
       vprintk+0x7f/0xa0 kernel/printk/printk_safe.c:45
       _printk+0xc8/0x100 kernel/printk/printk.c:2373
       fail_dump lib/fault-inject.c:45 [inline]
       should_fail_ex+0x46c/0x5b0 lib/fault-inject.c:153
       strncpy_from_user+0x38/0x320 lib/strncpy_from_user.c:118
       strncpy_from_user_nofault+0x7f/0x180 mm/maccess.c:186
       bpf_probe_read_user_str_common kernel/trace/bpf_trace.c:216 [inline]
       ____bpf_probe_read_user_str kernel/trace/bpf_trace.c:225 [inline]
       bpf_probe_read_user_str+0x26/0x70 kernel/trace/bpf_trace.c:222
       bpf_prog_bc7c5c6b9645592f+0x3d/0x3f
       bpf_dispatcher_nop_func include/linux/bpf.h:1243 [inline]
       __bpf_prog_run include/linux/filter.h:691 [inline]
       bpf_prog_run include/linux/filter.h:698 [inline]
       __bpf_trace_run kernel/trace/bpf_trace.c:2406 [inline]
       bpf_trace_run4+0x245/0x5a0 kernel/trace/bpf_trace.c:2449
       __bpf_trace_sched_switch+0x13e/0x190 include/trace/events/sched.h:222
       trace_sched_switch include/trace/events/sched.h:222 [inline]
       __schedule+0x17cf/0x5490 kernel/sched/core.c:6526
       __schedule_loop kernel/sched/core.c:6606 [inline]
       schedule+0xe7/0x350 kernel/sched/core.c:6621
       exit_to_user_mode_loop kernel/entry/common.c:102 [inline]
       exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
       __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
       syscall_exit_to_user_mode+0xf5/0x2a0 kernel/entry/common.c:218
       do_syscall_64+0xda/0x250 arch/x86/entry/common.c:89
       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 ***

2 locks held by syz.1.76/5659:
 #0: ffff88806a63edd8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:568 [inline]
 #0: ffff88806a63edd8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x7e/0x130 kernel/sched/core.c:553
 #1: ffffffff8ddb9fe0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline]
 #1: ffffffff8ddb9fe0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
 #1: ffffffff8ddb9fe0 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2405 [inline]
 #1: ffffffff8ddb9fe0 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run4+0x1d6/0x5a0 kernel/trace/bpf_trace.c:2449

stack backtrace:
CPU: 0 UID: 0 PID: 5659 Comm: syz.1.76 Not tainted 6.11.0-rc6-syzkaller-00326-gd1f2d51b711a #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:93 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:119
 check_noncircular+0x31a/0x400 kernel/locking/lockdep.c:2186
 check_prev_add kernel/locking/lockdep.c:3133 [inline]
 check_prevs_add kernel/locking/lockdep.c:3252 [inline]
 validate_chain kernel/locking/lockdep.c:3868 [inline]
 __lock_acquire+0x24ed/0x3cb0 kernel/locking/lockdep.c:5142
 lock_acquire kernel/locking/lockdep.c:5759 [inline]
 lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5724
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162
 down_trylock+0x12/0x70 kernel/locking/semaphore.c:139
 __down_trylock_console_sem+0x40/0x140 kernel/printk/printk.c:323
 console_trylock kernel/printk/printk.c:2754 [inline]
 console_trylock_spinning kernel/printk/printk.c:1958 [inline]
 vprintk_emit+0x3d3/0x600 kernel/printk/printk.c:2347
 vprintk+0x7f/0xa0 kernel/printk/printk_safe.c:45
 _printk+0xc8/0x100 kernel/printk/printk.c:2373
 fail_dump lib/fault-inject.c:45 [inline]
 should_fail_ex+0x46c/0x5b0 lib/fault-inject.c:153
 strncpy_from_user+0x38/0x320 lib/strncpy_from_user.c:118
 strncpy_from_user_nofault+0x7f/0x180 mm/maccess.c:186
 bpf_probe_read_user_str_common kernel/trace/bpf_trace.c:216 [inline]
 ____bpf_probe_read_user_str kernel/trace/bpf_trace.c:225 [inline]
 bpf_probe_read_user_str+0x26/0x70 kernel/trace/bpf_trace.c:222
 bpf_prog_bc7c5c6b9645592f+0x3d/0x3f
 bpf_dispatcher_nop_func include/linux/bpf.h:1243 [inline]
 __bpf_prog_run include/linux/filter.h:691 [inline]
 bpf_prog_run include/linux/filter.h:698 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:2406 [inline]
 bpf_trace_run4+0x245/0x5a0 kernel/trace/bpf_trace.c:2449
 __bpf_trace_sched_switch+0x13e/0x190 include/trace/events/sched.h:222
 trace_sched_switch include/trace/events/sched.h:222 [inline]
 __schedule+0x17cf/0x5490 kernel/sched/core.c:6526
 __schedule_loop kernel/sched/core.c:6606 [inline]
 schedule+0xe7/0x350 kernel/sched/core.c:6621
 exit_to_user_mode_loop kernel/entry/common.c:102 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0xf5/0x2a0 kernel/entry/common.c:218
 do_syscall_64+0xda/0x250 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa78bf7b9df
Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 c9 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 1c 8e 02 00 48
RSP: 002b:00007fa78cd85030 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: 0000000000000001 RBX: 0000000000000004 RCX: 00007fa78bf7b9df
RDX: 0000000000000001 RSI: 00007fa78cd85090 RDI: 0000000000000004
RBP: 00007fa78cd85090 R08: 0000000000000000 R09: 00007fa78cd84df7
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000001
R13: 0000000000000000 R14: 00007fa78c135f80 R15: 00007ffd37f623c8
 </TASK>
CPU: 0 UID: 0 PID: 5659 Comm: syz.1.76 Not tainted 6.11.0-rc6-syzkaller-00326-gd1f2d51b711a #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:93 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:119
 fail_dump lib/fault-inject.c:52 [inline]
 should_fail_ex+0x497/0x5b0 lib/fault-inject.c:153
 strncpy_from_user+0x38/0x320 lib/strncpy_from_user.c:118
 strncpy_from_user_nofault+0x7f/0x180 mm/maccess.c:186
 bpf_probe_read_user_str_common kernel/trace/bpf_trace.c:216 [inline]
 ____bpf_probe_read_user_str kernel/trace/bpf_trace.c:225 [inline]
 bpf_probe_read_user_str+0x26/0x70 kernel/trace/bpf_trace.c:222
 bpf_prog_bc7c5c6b9645592f+0x3d/0x3f
 bpf_dispatcher_nop_func include/linux/bpf.h:1243 [inline]
 __bpf_prog_run include/linux/filter.h:691 [inline]
 bpf_prog_run include/linux/filter.h:698 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:2406 [inline]
 bpf_trace_run4+0x245/0x5a0 kernel/trace/bpf_trace.c:2449
 __bpf_trace_sched_switch+0x13e/0x190 include/trace/events/sched.h:222
 trace_sched_switch include/trace/events/sched.h:222 [inline]
 __schedule+0x17cf/0x5490 kernel/sched/core.c:6526
 __schedule_loop kernel/sched/core.c:6606 [inline]
 schedule+0xe7/0x350 kernel/sched/core.c:6621
 exit_to_user_mode_loop kernel/entry/common.c:102 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0xf5/0x2a0 kernel/entry/common.c:218
 do_syscall_64+0xda/0x250 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa78bf7b9df
Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 c9 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 1c 8e 02 00 48
RSP: 002b:00007fa78cd85030 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: 0000000000000001 RBX: 0000000000000004 RCX: 00007fa78bf7b9df
RDX: 0000000000000001 RSI: 00007fa78cd85090 RDI: 0000000000000004
RBP: 00007fa78cd85090 R08: 0000000000000000 R09: 00007fa78cd84df7
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000001
R13: 0000000000000000 R14: 00007fa78c135f80 R15: 00007ffd37f623c8
 </TASK>