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-00166-g334426094588 #0 Not tainted
------------------------------------------------------
syz.4.1964/10929 is trying to acquire lock:
ffffffff8e1aa9f8 ((console_sem).lock){-...}-{2:2}, at: down_trylock+0x12/0x70 kernel/locking/semaphore.c:139

but task is already holding lock:
ffff88806a73ec18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x29/0x130 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}:
       _raw_spin_lock_nested+0x31/0x40 kernel/locking/spinlock.c:378
       raw_spin_rq_lock_nested+0x29/0x130 kernel/sched/core.c:598
       raw_spin_rq_lock kernel/sched/sched.h:1521 [inline]
       task_rq_lock+0xcf/0x3b0 kernel/sched/core.c:700
       cgroup_move_task+0x82/0x250 kernel/sched/psi.c:1161
       css_set_move_task+0x288/0x5f0 kernel/cgroup/cgroup.c:898
       cgroup_post_fork+0x202/0x9d0 kernel/cgroup/cgroup.c:6695
       copy_process+0x4ffd/0x8c50 kernel/fork.c:2629
       kernel_clone+0xfd/0x960 kernel/fork.c:2815
       user_mode_thread+0xc9/0x110 kernel/fork.c:2893
       rest_init+0x23/0x2b0 init/main.c:708
       start_kernel+0x3e9/0x4d0 init/main.c:1099
       x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:515
       x86_64_start_kernel+0xb2/0xc0 arch/x86/kernel/head64.c:496
       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+0xb6/0x1490 kernel/sched/core.c:4214
       up+0x79/0xb0 kernel/locking/semaphore.c:191
       __up_console_sem+0x85/0xe0 kernel/printk/printk.c:343
       __console_unlock kernel/printk/printk.c:2869 [inline]
       __console_flush_and_unlock kernel/printk/printk.c:3271 [inline]
       console_unlock+0x1dc/0x210 kernel/printk/printk.c:3309
       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:62 [inline]
       virtio_gpu_probe+0x409/0x4f0 drivers/gpu/drm/virtio/virtgpu_drv.c:93
       virtio_dev_probe+0x586/0x8a0 drivers/virtio/virtio.c:341
       call_driver_probe drivers/base/dd.c:579 [inline]
       really_probe+0x23e/0xa90 drivers/base/dd.c:658
       __driver_probe_device+0x1de/0x440 drivers/base/dd.c:800
       driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:830
       __driver_attach+0x283/0x580 drivers/base/dd.c:1216
       bus_for_each_dev+0x13c/0x1d0 drivers/base/bus.c:370
       bus_add_driver+0x2e9/0x690 drivers/base/bus.c:678
       driver_register+0x15c/0x4b0 drivers/base/driver.c:249
       do_one_initcall+0x128/0x700 init/main.c:1257
       do_initcall_level init/main.c:1319 [inline]
       do_initcalls init/main.c:1335 [inline]
       do_basic_setup init/main.c:1354 [inline]
       kernel_init_freeable+0x5c7/0x900 init/main.c:1568
       kernel_init+0x1c/0x2b0 init/main.c:1457
       ret_from_fork+0x45/0x80 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 kernel/locking/lockdep.c:3906 [inline]
       __lock_acquire+0x249e/0x3c40 kernel/locking/lockdep.c:5228
       lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5851
       __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:326
       console_trylock kernel/printk/printk.c:2852 [inline]
       console_trylock_spinning kernel/printk/printk.c:2009 [inline]
       vprintk_emit+0x3ec/0x6f0 kernel/printk/printk.c:2431
       _printk+0xc8/0x100 kernel/printk/printk.c:2457
       fail_dump lib/fault-inject.c:66 [inline]
       should_fail_ex+0x4df/0x650 lib/fault-inject.c:174
       strncpy_from_user+0x3b/0x2d0 lib/strncpy_from_user.c:118
       strncpy_from_user_nofault+0x7f/0x180 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+0xf1/0x170 kernel/trace/bpf_trace.c:306
       bpf_prog_c1796171ffc7efef+0x3e/0x40
       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:2371 [inline]
       bpf_trace_run4+0x245/0x5a0 kernel/trace/bpf_trace.c:2414
       __bpf_trace_sched_switch+0x13e/0x190 include/trace/events/sched.h:222
       __traceiter_sched_switch+0x6c/0xc0 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+0x160c/0x5890 kernel/sched/core.c:6762
       __schedule_loop kernel/sched/core.c:6842 [inline]
       schedule+0xe7/0x350 kernel/sched/core.c:6857
       schedule_timeout+0x244/0x280 kernel/time/sleep_timeout.c:75
       __skb_wait_for_more_packets+0x36c/0x5e0 net/core/datagram.c:121
       __skb_recv_datagram+0x16d/0x220 net/core/datagram.c:304
       skb_recv_datagram+0x89/0xc0 net/core/datagram.c:316
       raw_recvmsg+0xfb/0x7a0 net/ipv4/raw.c:756
       inet_recvmsg+0x469/0x6a0 net/ipv4/af_inet.c:883
       sock_recvmsg_nosec net/socket.c:1023 [inline]
       sock_recvmsg+0x1b2/0x250 net/socket.c:1045
       ____sys_recvmsg+0x219/0x6b0 net/socket.c:2793
       ___sys_recvmsg+0x115/0x1a0 net/socket.c:2835
       do_recvmmsg+0x2f8/0x740 net/socket.c:2930
       __sys_recvmmsg net/socket.c:3004 [inline]
       __do_sys_recvmmsg net/socket.c:3027 [inline]
       __se_sys_recvmmsg net/socket.c:3020 [inline]
       __x64_sys_recvmmsg+0x239/0x290 net/socket.c:3020
       do_syscall_x64 arch/x86/entry/common.c:52 [inline]
       do_syscall_64+0xcd/0x250 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 ***

2 locks held by syz.4.1964/10929:
 #0: ffff88806a73ec18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x29/0x130 kernel/sched/core.c:598
 #1: ffffffff8e1bcc80 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
 #1: ffffffff8e1bcc80 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #1: ffffffff8e1bcc80 (rcu_read_lock){....}-{1:3}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2370 [inline]
 #1: ffffffff8e1bcc80 (rcu_read_lock){....}-{1:3}, at: bpf_trace_run4+0x1d6/0x5a0 kernel/trace/bpf_trace.c:2414

stack backtrace:
CPU: 1 UID: 0 PID: 10929 Comm: syz.4.1964 Not tainted 6.14.0-rc3-syzkaller-00166-g334426094588 #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:94 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
 print_circular_bug+0x490/0x760 kernel/locking/lockdep.c:2076
 check_noncircular+0x31a/0x400 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 kernel/locking/lockdep.c:3906 [inline]
 __lock_acquire+0x249e/0x3c40 kernel/locking/lockdep.c:5228
 lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5851
 __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:326
 console_trylock kernel/printk/printk.c:2852 [inline]
 console_trylock_spinning kernel/printk/printk.c:2009 [inline]
 vprintk_emit+0x3ec/0x6f0 kernel/printk/printk.c:2431
 _printk+0xc8/0x100 kernel/printk/printk.c:2457
 fail_dump lib/fault-inject.c:66 [inline]
 should_fail_ex+0x4df/0x650 lib/fault-inject.c:174
 strncpy_from_user+0x3b/0x2d0 lib/strncpy_from_user.c:118
 strncpy_from_user_nofault+0x7f/0x180 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+0xf1/0x170 kernel/trace/bpf_trace.c:306
 bpf_prog_c1796171ffc7efef+0x3e/0x40
 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:2371 [inline]
 bpf_trace_run4+0x245/0x5a0 kernel/trace/bpf_trace.c:2414
 __bpf_trace_sched_switch+0x13e/0x190 include/trace/events/sched.h:222
 __traceiter_sched_switch+0x6c/0xc0 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+0x160c/0x5890 kernel/sched/core.c:6762
 __schedule_loop kernel/sched/core.c:6842 [inline]
 schedule+0xe7/0x350 kernel/sched/core.c:6857
 schedule_timeout+0x244/0x280 kernel/time/sleep_timeout.c:75
 __skb_wait_for_more_packets+0x36c/0x5e0 net/core/datagram.c:121
 __skb_recv_datagram+0x16d/0x220 net/core/datagram.c:304
 skb_recv_datagram+0x89/0xc0 net/core/datagram.c:316
 raw_recvmsg+0xfb/0x7a0 net/ipv4/raw.c:756
 inet_recvmsg+0x469/0x6a0 net/ipv4/af_inet.c:883
 sock_recvmsg_nosec net/socket.c:1023 [inline]
 sock_recvmsg+0x1b2/0x250 net/socket.c:1045
 ____sys_recvmsg+0x219/0x6b0 net/socket.c:2793
 ___sys_recvmsg+0x115/0x1a0 net/socket.c:2835
 do_recvmmsg+0x2f8/0x740 net/socket.c:2930
 __sys_recvmmsg net/socket.c:3004 [inline]
 __do_sys_recvmmsg net/socket.c:3027 [inline]
 __se_sys_recvmmsg net/socket.c:3020 [inline]
 __x64_sys_recvmmsg+0x239/0x290 net/socket.c:3020
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb613d8d0a9
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:00007fb614bd6038 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 00007fb613fa5fa0 RCX: 00007fb613d8d0a9
RDX: 0000000000000001 RSI: 0000400000006480 RDI: 0000000000000003
RBP: 00007fb614bd6090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000040010102 R11: 0000000000000246 R12: 0000000000000001
R13: 0000000000000000 R14: 00007fb613fa5fa0 R15: 00007ffffef4f4d8
 </TASK>
CPU: 1 UID: 0 PID: 10929 Comm: syz.4.1964 Not tainted 6.14.0-rc3-syzkaller-00166-g334426094588 #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:94 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
 fail_dump lib/fault-inject.c:73 [inline]
 should_fail_ex+0x50a/0x650 lib/fault-inject.c:174
 strncpy_from_user+0x3b/0x2d0 lib/strncpy_from_user.c:118
 strncpy_from_user_nofault+0x7f/0x180 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+0xf1/0x170 kernel/trace/bpf_trace.c:306
 bpf_prog_c1796171ffc7efef+0x3e/0x40
 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:2371 [inline]
 bpf_trace_run4+0x245/0x5a0 kernel/trace/bpf_trace.c:2414
 __bpf_trace_sched_switch+0x13e/0x190 include/trace/events/sched.h:222
 __traceiter_sched_switch+0x6c/0xc0 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+0x160c/0x5890 kernel/sched/core.c:6762
 __schedule_loop kernel/sched/core.c:6842 [inline]
 schedule+0xe7/0x350 kernel/sched/core.c:6857
 schedule_timeout+0x244/0x280 kernel/time/sleep_timeout.c:75
 __skb_wait_for_more_packets+0x36c/0x5e0 net/core/datagram.c:121
 __skb_recv_datagram+0x16d/0x220 net/core/datagram.c:304
 skb_recv_datagram+0x89/0xc0 net/core/datagram.c:316
 raw_recvmsg+0xfb/0x7a0 net/ipv4/raw.c:756
 inet_recvmsg+0x469/0x6a0 net/ipv4/af_inet.c:883
 sock_recvmsg_nosec net/socket.c:1023 [inline]
 sock_recvmsg+0x1b2/0x250 net/socket.c:1045
 ____sys_recvmsg+0x219/0x6b0 net/socket.c:2793
 ___sys_recvmsg+0x115/0x1a0 net/socket.c:2835
 do_recvmmsg+0x2f8/0x740 net/socket.c:2930
 __sys_recvmmsg net/socket.c:3004 [inline]
 __do_sys_recvmmsg net/socket.c:3027 [inline]
 __se_sys_recvmmsg net/socket.c:3020 [inline]
 __x64_sys_recvmmsg+0x239/0x290 net/socket.c:3020
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb613d8d0a9
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:00007fb614bd6038 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 00007fb613fa5fa0 RCX: 00007fb613d8d0a9
RDX: 0000000000000001 RSI: 0000400000006480 RDI: 0000000000000003
RBP: 00007fb614bd6090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000040010102 R11: 0000000000000246 R12: 0000000000000001
R13: 0000000000000000 R14: 00007fb613fa5fa0 R15: 00007ffffef4f4d8
 </TASK>