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-00355-g5dadc1be8fc5 #0 Not tainted
------------------------------------------------------
syz.1.2775/15700 is trying to acquire lock:
ffffffff8dda75d8 ((console_sem).lock){-.-.}-{2:2}, at: down_trylock+0x12/0x70 kernel/locking/semaphore.c:139

but task is already holding lock:
ffff88802b73edd8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x29/0x130 kernel/sched/core.c:560

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+0x4710/0x6f50 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
       bochs_pci_probe+0x101/0x1150 drivers/gpu/drm/tiny/bochs.c:648
       local_pci_probe+0xde/0x1b0 drivers/pci/pci-driver.c:324
       pci_call_probe drivers/pci/pci-driver.c:392 [inline]
       __pci_device_probe drivers/pci/pci-driver.c:417 [inline]
       pci_device_probe+0x29d/0x7b0 drivers/pci/pci-driver.c:451
       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
       drm_pci_register_driver_if_modeset include/drm/drm_module.h:69 [inline]
       bochs_pci_driver_init+0x67/0x80 drivers/gpu/drm/tiny/bochs.c:732
       do_one_initcall+0x128/0x630 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+0x660/0xc50 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_compat_str kernel/trace/bpf_trace.c:311 [inline]
       bpf_probe_read_compat_str+0x131/0x170 kernel/trace/bpf_trace.c:307
       bpf_prog_1ccb8ba97563bf77+0x40/0x63
       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_run2+0x231/0x590 kernel/trace/bpf_trace.c:2447
       trace_tlb_flush+0xf3/0x170 include/trace/events/tlb.h:38
       switch_mm_irqs_off+0x697/0xbb0 arch/x86/mm/tlb.c:642
       context_switch kernel/sched/core.c:5172 [inline]
       __schedule+0xc4d/0x5490 kernel/sched/core.c:6529
       __schedule_loop kernel/sched/core.c:6606 [inline]
       schedule+0xe7/0x350 kernel/sched/core.c:6621
       schedule_timeout+0x258/0x2a0 kernel/time/timer.c:2557
       do_wait_for_common kernel/sched/completion.c:95 [inline]
       __wait_for_common+0x3de/0x5f0 kernel/sched/completion.c:116
       __flush_work+0x776/0xc30 kernel/workqueue.c:4212
       __lru_add_drain_all+0x52c/0x740 mm/swap.c:920
       madvise_collapse+0x227/0xac0 mm/khugepaged.c:2728
       madvise_vma_behavior+0x349/0x18e0 mm/madvise.c:1097
       madvise_walk_vmas+0x1cf/0x2c0 mm/madvise.c:1271
       do_madvise+0x310/0x7a0 mm/madvise.c:1467
       __do_sys_madvise mm/madvise.c:1484 [inline]
       __se_sys_madvise mm/madvise.c:1482 [inline]
       __ia32_sys_madvise+0xa7/0x110 mm/madvise.c:1482
       do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline]
       __do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386
       do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411
       entry_SYSENTER_compat_after_hwframe+0x84/0x8e

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 ***

4 locks held by syz.1.2775/15700:
 #0: ffff88802343cd98 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_lock include/linux/mmap_lock.h:144 [inline]
 #0: ffff88802343cd98 (&mm->mmap_lock){++++}-{3:3}, at: do_madvise+0x44e/0x7a0 mm/madvise.c:1445
 #1: ffffffff8dedbd88 (lock#3){+.+.}-{3:3}, at: __lru_add_drain_all+0x69/0x740 mm/swap.c:875
 #2: ffff88802b73edd8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x29/0x130 kernel/sched/core.c:560
 #3: ffffffff8ddb94a0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline]
 #3: ffffffff8ddb94a0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
 #3: ffffffff8ddb94a0 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2405 [inline]
 #3: ffffffff8ddb94a0 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0x1c2/0x590 kernel/trace/bpf_trace.c:2447

stack backtrace:
CPU: 1 UID: 0 PID: 15700 Comm: syz.1.2775 Not tainted 6.11.0-rc6-syzkaller-00355-g5dadc1be8fc5 #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_compat_str kernel/trace/bpf_trace.c:311 [inline]
 bpf_probe_read_compat_str+0x131/0x170 kernel/trace/bpf_trace.c:307
 bpf_prog_1ccb8ba97563bf77+0x40/0x63
 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_run2+0x231/0x590 kernel/trace/bpf_trace.c:2447
 trace_tlb_flush+0xf3/0x170 include/trace/events/tlb.h:38
 switch_mm_irqs_off+0x697/0xbb0 arch/x86/mm/tlb.c:642
 context_switch kernel/sched/core.c:5172 [inline]
 __schedule+0xc4d/0x5490 kernel/sched/core.c:6529
 __schedule_loop kernel/sched/core.c:6606 [inline]
 schedule+0xe7/0x350 kernel/sched/core.c:6621
 schedule_timeout+0x258/0x2a0 kernel/time/timer.c:2557
 do_wait_for_common kernel/sched/completion.c:95 [inline]
 __wait_for_common+0x3de/0x5f0 kernel/sched/completion.c:116
 __flush_work+0x776/0xc30 kernel/workqueue.c:4212
 __lru_add_drain_all+0x52c/0x740 mm/swap.c:920
 madvise_collapse+0x227/0xac0 mm/khugepaged.c:2728
 madvise_vma_behavior+0x349/0x18e0 mm/madvise.c:1097
 madvise_walk_vmas+0x1cf/0x2c0 mm/madvise.c:1271
 do_madvise+0x310/0x7a0 mm/madvise.c:1467
 __do_sys_madvise mm/madvise.c:1484 [inline]
 __se_sys_madvise mm/madvise.c:1482 [inline]
 __ia32_sys_madvise+0xa7/0x110 mm/madvise.c:1482
 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline]
 __do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386
 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf7f53579
Code: Unable to access opcode bytes at 0xf7f5354f.
RSP: 002b:00000000f56e656c EFLAGS: 00000296 ORIG_RAX: 00000000000000db
RAX: ffffffffffffffda RBX: 0000000020000000 RCX: 0000000000600003
RDX: 0000000000000019 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
CPU: 1 UID: 0 PID: 15700 Comm: syz.1.2775 Not tainted 6.11.0-rc6-syzkaller-00355-g5dadc1be8fc5 #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_compat_str kernel/trace/bpf_trace.c:311 [inline]
 bpf_probe_read_compat_str+0x131/0x170 kernel/trace/bpf_trace.c:307
 bpf_prog_1ccb8ba97563bf77+0x40/0x63
 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_run2+0x231/0x590 kernel/trace/bpf_trace.c:2447
 trace_tlb_flush+0xf3/0x170 include/trace/events/tlb.h:38
 switch_mm_irqs_off+0x697/0xbb0 arch/x86/mm/tlb.c:642
 context_switch kernel/sched/core.c:5172 [inline]
 __schedule+0xc4d/0x5490 kernel/sched/core.c:6529
 __schedule_loop kernel/sched/core.c:6606 [inline]
 schedule+0xe7/0x350 kernel/sched/core.c:6621
 schedule_timeout+0x258/0x2a0 kernel/time/timer.c:2557
 do_wait_for_common kernel/sched/completion.c:95 [inline]
 __wait_for_common+0x3de/0x5f0 kernel/sched/completion.c:116
 __flush_work+0x776/0xc30 kernel/workqueue.c:4212
 __lru_add_drain_all+0x52c/0x740 mm/swap.c:920
 madvise_collapse+0x227/0xac0 mm/khugepaged.c:2728
 madvise_vma_behavior+0x349/0x18e0 mm/madvise.c:1097
 madvise_walk_vmas+0x1cf/0x2c0 mm/madvise.c:1271
 do_madvise+0x310/0x7a0 mm/madvise.c:1467
 __do_sys_madvise mm/madvise.c:1484 [inline]
 __se_sys_madvise mm/madvise.c:1482 [inline]
 __ia32_sys_madvise+0xa7/0x110 mm/madvise.c:1482
 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline]
 __do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386
 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf7f53579
Code: Unable to access opcode bytes at 0xf7f5354f.
RSP: 002b:00000000f56e656c EFLAGS: 00000296 ORIG_RAX: 00000000000000db
RAX: ffffffffffffffda RBX: 0000000020000000 RCX: 0000000000600003
RDX: 0000000000000019 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>