openvswitch: netlink: Flow key attr not present in new flow.
FAULT_INJECTION: forcing a failure.
name fail_usercopy, interval 1, probability 0, space 0, times 0
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.5.3052/17087 is trying to acquire lock:
ffffffff8e0d12c0 (console_owner){-.-.}-{0:0}, at: console_lock_spinning_enable+0x61/0x80 kernel/printk/printk.c:1897

but task is already holding lock:
ffff88802b43a498 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:646 [inline]
ffff88802b43a498 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x7e/0x130 kernel/sched/core.c:631

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #4 (&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:638
       raw_spin_rq_lock kernel/sched/sched.h:1546 [inline]
       task_rq_lock+0xcf/0x490 kernel/sched/core.c:738
       cgroup_move_task+0x81/0x2a0 kernel/sched/psi.c:1170
       css_set_move_task+0x288/0x5f0 kernel/cgroup/cgroup.c:951
       cgroup_post_fork+0x201/0x9d0 kernel/cgroup/cgroup.c:6913
       copy_process+0x602d/0x76a0 kernel/fork.c:2425
       kernel_clone+0xfc/0x930 kernel/fork.c:2609
       user_mode_thread+0xc8/0x110 kernel/fork.c:2685
       rest_init+0x23/0x2b0 init/main.c:722
       start_kernel+0x3f3/0x4e0 init/main.c:1111
       x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:310
       x86_64_start_kernel+0x130/0x190 arch/x86/kernel/head64.c:291
       common_startup_64+0x13e/0x148

-> #3 (&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:557 [inline]
       try_to_wake_up+0xb7/0x1870 kernel/sched/core.c:4181
       __wake_up_common+0x135/0x1f0 kernel/sched/wait.c:108
       __wake_up_common_lock kernel/sched/wait.c:125 [inline]
       __wake_up+0x31/0x60 kernel/sched/wait.c:146
       tty_port_default_wakeup+0x2a/0x40 drivers/tty/tty_port.c:69
       serial8250_tx_chars+0x68e/0x860 drivers/tty/serial/8250/8250_port.c:1728
       serial8250_handle_irq+0x761/0xcb0 drivers/tty/serial/8250/8250_port.c:1836
       serial8250_default_handle_irq+0x9a/0x250 drivers/tty/serial/8250/8250_port.c:1856
       serial8250_interrupt+0xf5/0x1b0 drivers/tty/serial/8250/8250_core.c:82
       __handle_irq_event_percpu+0x236/0x920 kernel/irq/handle.c:203
       handle_irq_event_percpu kernel/irq/handle.c:240 [inline]
       handle_irq_event+0xab/0x1e0 kernel/irq/handle.c:257
       handle_edge_irq+0x3ca/0x9e0 kernel/irq/chip.c:855
       generic_handle_irq_desc include/linux/irqdesc.h:173 [inline]
       handle_irq arch/x86/kernel/irq.c:254 [inline]
       call_irq_handler arch/x86/kernel/irq.c:310 [inline]
       __common_interrupt+0xd0/0x2f0 arch/x86/kernel/irq.c:325
       common_interrupt+0x61/0xe0 arch/x86/kernel/irq.c:318
       asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:693
       unwind_next_frame+0x1617/0x20a0 arch/x86/kernel/unwind_orc.c:665
       arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25
       stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
       kasan_save_stack+0x33/0x60 mm/kasan/common.c:56
       kasan_save_track+0x14/0x30 mm/kasan/common.c:77
       __kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:587
       kasan_save_free_info mm/kasan/kasan.h:406 [inline]
       poison_slab_object mm/kasan/common.c:252 [inline]
       __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:284
       kasan_slab_free include/linux/kasan.h:234 [inline]
       slab_free_hook mm/slub.c:2514 [inline]
       __rcu_free_sheaf_prepare+0x52/0x300 mm/slub.c:2720
       rcu_free_sheaf+0x1a/0xa0 mm/slub.c:6139
       rcu_do_batch kernel/rcu/tree.c:2605 [inline]
       rcu_core+0x79c/0x1530 kernel/rcu/tree.c:2861
       handle_softirqs+0x216/0x8e0 kernel/softirq.c:622
       __do_softirq kernel/softirq.c:656 [inline]
       invoke_softirq kernel/softirq.c:496 [inline]
       __irq_exit_rcu+0x109/0x170 kernel/softirq.c:723
       irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
       instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline]
       sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1052
       asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
       native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline]
       pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:81
       arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
       default_idle+0x13/0x20 arch/x86/kernel/process.c:757
       default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122
       cpuidle_idle_call kernel/sched/idle.c:190 [inline]
       do_idle+0x38d/0x500 kernel/sched/idle.c:330
       cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:428
       start_secondary+0x21d/0x2b0 arch/x86/kernel/smpboot.c:315
       common_startup_64+0x13e/0x148

-> #2 (&tty->write_wait){-.-.}-{3:3}:
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162
       __wake_up_common_lock kernel/sched/wait.c:124 [inline]
       __wake_up+0x1c/0x60 kernel/sched/wait.c:146
       tty_port_default_wakeup+0x2a/0x40 drivers/tty/tty_port.c:69
       serial8250_tx_chars+0x68e/0x860 drivers/tty/serial/8250/8250_port.c:1728
       __start_tx+0x3df/0x490 drivers/tty/serial/8250/8250_port.c:1433
       serial8250_start_tx+0x368/0x530 drivers/tty/serial/8250/8250_port.c:1543
       __uart_start+0x295/0x500 drivers/tty/serial/serial_core.c:161
       uart_write+0x218/0xb30 drivers/tty/serial/serial_core.c:636
       process_output_block drivers/tty/n_tty.c:561 [inline]
       n_tty_write+0x41b/0x11e0 drivers/tty/n_tty.c:2377
       iterate_tty_write drivers/tty/tty_io.c:1006 [inline]
       file_tty_write.constprop.0+0x503/0x9b0 drivers/tty/tty_io.c:1081
       tty_write drivers/tty/tty_io.c:1102 [inline]
       redirected_tty_write drivers/tty/tty_io.c:1125 [inline]
       redirected_tty_write+0xd4/0x150 drivers/tty/tty_io.c:1105
       new_sync_write fs/read_write.c:593 [inline]
       vfs_write+0x7d0/0x11d0 fs/read_write.c:686
       ksys_write+0x12a/0x250 fs/read_write.c:738
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0xcd/0x4b0 arch/x86/entry/syscall_64.c:94
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #1 (&port_lock_key){-.-.}-{3:3}:
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162
       uart_port_lock_irqsave include/linux/serial_core.h:717 [inline]
       serial8250_console_write+0x181/0x1890 drivers/tty/serial/8250/8250_port.c:3355
       console_emit_next_record kernel/printk/printk.c:3111 [inline]
       console_flush_all+0x801/0xc60 kernel/printk/printk.c:3199
       __console_flush_and_unlock kernel/printk/printk.c:3258 [inline]
       console_unlock+0xd8/0x210 kernel/printk/printk.c:3298
       vprintk_emit+0x3d7/0x680 kernel/printk/printk.c:2423
       _printk+0xc7/0x100 kernel/printk/printk.c:2448
       register_console+0xc2d/0x11b0 kernel/printk/printk.c:4099
       univ8250_console_init+0x5f/0x90 drivers/tty/serial/8250/8250_core.c:516
       console_init+0x14f/0x680 kernel/printk/printk.c:4298
       start_kernel+0x29f/0x4e0 init/main.c:1048
       x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:310
       x86_64_start_kernel+0x130/0x190 arch/x86/kernel/head64.c:291
       common_startup_64+0x13e/0x148

-> #0 (console_owner){-.-.}-{0:0}:
       check_prev_add kernel/locking/lockdep.c:3165 [inline]
       check_prevs_add kernel/locking/lockdep.c:3284 [inline]
       validate_chain kernel/locking/lockdep.c:3908 [inline]
       __lock_acquire+0x12a6/0x1ce0 kernel/locking/lockdep.c:5237
       lock_acquire kernel/locking/lockdep.c:5868 [inline]
       lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5825
       console_lock_spinning_enable+0x72/0x80 kernel/printk/printk.c:1897
       console_emit_next_record kernel/printk/printk.c:3105 [inline]
       console_flush_all+0x7aa/0xc60 kernel/printk/printk.c:3199
       __console_flush_and_unlock kernel/printk/printk.c:3258 [inline]
       console_unlock+0xd8/0x210 kernel/printk/printk.c:3298
       vprintk_emit+0x3d7/0x680 kernel/printk/printk.c:2423
       _printk+0xc7/0x100 kernel/printk/printk.c:2448
       fail_dump lib/fault-inject.c:66 [inline]
       should_fail_ex+0x4e7/0x640 lib/fault-inject.c:174
       strncpy_from_user+0x3b/0x2e0 lib/strncpy_from_user.c:118
       strncpy_from_user_nofault+0x7f/0x180 mm/maccess.c:192
       bpf_trace_copy_string kernel/bpf/helpers.c:764 [inline]
       bpf_bprintf_prepare+0xe90/0x13f0 kernel/bpf/helpers.c:976
       ____bpf_trace_printk kernel/trace/bpf_trace.c:372 [inline]
       bpf_trace_printk+0xda/0x190 kernel/trace/bpf_trace.c:362
       bpf_prog_930ede9872f2967c+0x3e/0x44
       bpf_dispatcher_nop_func include/linux/bpf.h:1350 [inline]
       __bpf_prog_run include/linux/filter.h:721 [inline]
       bpf_prog_run include/linux/filter.h:728 [inline]
       __bpf_trace_run kernel/trace/bpf_trace.c:2075 [inline]
       bpf_trace_run2+0x236/0x590 kernel/trace/bpf_trace.c:2116
       __bpf_trace_contention_begin+0xc9/0x110 include/trace/events/lock.h:95
       __preempt_count_dec_and_test arch/x86/include/asm/preempt.h:95 [inline]
       class_preempt_notrace_destructor include/linux/preempt.h:471 [inline]
       __do_trace_contention_begin include/trace/events/lock.h:95 [inline]
       trace_contention_begin.constprop.0+0xde/0x160 include/trace/events/lock.h:95
       __pv_queued_spin_lock_slowpath+0x109/0xcf0 kernel/locking/qspinlock.c:219
       pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:557 [inline]
       queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:51 [inline]
       queued_spin_lock include/asm-generic/qspinlock.h:114 [inline]
       do_raw_spin_lock+0x20e/0x2b0 kernel/locking/spinlock_debug.c:116
       raw_spin_rq_lock_nested kernel/sched/core.c:646 [inline]
       raw_spin_rq_lock_nested+0x7e/0x130 kernel/sched/core.c:631
       raw_spin_rq_lock kernel/sched/sched.h:1546 [inline]
       rq_lock kernel/sched/sched.h:1868 [inline]
       __schedule+0x307/0x5de0 kernel/sched/core.c:6833
       preempt_schedule_common+0x44/0xc0 kernel/sched/core.c:7113
       preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
       vprintk_emit+0x408/0x680 kernel/printk/printk.c:2424
       _printk+0xc7/0x100 kernel/printk/printk.c:2448
       ovs_flow_cmd_new+0x9f3/0xe30 net/openvswitch/datapath.c:1014
       genl_family_rcv_msg_doit+0x209/0x2f0 net/netlink/genetlink.c:1115
       genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline]
       genl_rcv_msg+0x55c/0x800 net/netlink/genetlink.c:1210
       netlink_rcv_skb+0x158/0x420 net/netlink/af_netlink.c:2552
       genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219
       netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
       netlink_unicast+0x5a7/0x870 net/netlink/af_netlink.c:1346
       netlink_sendmsg+0x8c8/0xdd0 net/netlink/af_netlink.c:1896
       sock_sendmsg_nosec net/socket.c:727 [inline]
       __sock_sendmsg net/socket.c:742 [inline]
       ____sys_sendmsg+0xa95/0xc70 net/socket.c:2630
       ___sys_sendmsg+0x134/0x1d0 net/socket.c:2684
       __sys_sendmsg+0x16d/0x220 net/socket.c:2716
       do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
       __do_fast_syscall_32+0x7c/0x300 arch/x86/entry/syscall_32.c:306
       do_fast_syscall_32+0x32/0x80 arch/x86/entry/syscall_32.c:331
       entry_SYSENTER_compat_after_hwframe+0x84/0x8e

other info that might help us debug this:

Chain exists of:
  console_owner --> &p->pi_lock --> &rq->__lock

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&rq->__lock);
                               lock(&p->pi_lock);
                               lock(&rq->__lock);
  lock(console_owner);

 *** DEADLOCK ***

5 locks held by syz.5.3052/17087:
 #0: ffffffff8ff83f30 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
 #1: ffff88802b43a498 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:646 [inline]
 #1: ffff88802b43a498 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x7e/0x130 kernel/sched/core.c:631
 #2: ffffffff8e1c3fa0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #2: ffffffff8e1c3fa0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
 #2: ffffffff8e1c3fa0 (rcu_read_lock){....}-{1:3}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2074 [inline]
 #2: ffffffff8e1c3fa0 (rcu_read_lock){....}-{1:3}, at: bpf_trace_run2+0x1bc/0x590 kernel/trace/bpf_trace.c:2116
 #3: ffffffff8e1b1700 (console_lock){+.+.}-{0:0}, at: _printk+0xc7/0x100 kernel/printk/printk.c:2448
 #4: ffffffff8e1b1770 (console_srcu){....}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:336 [inline]
 #4: ffffffff8e1b1770 (console_srcu){....}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:319 [inline]
 #4: ffffffff8e1b1770 (console_srcu){....}-{0:0}, at: console_srcu_read_lock kernel/printk/printk.c:289 [inline]
 #4: ffffffff8e1b1770 (console_srcu){....}-{0:0}, at: console_flush_all+0x158/0xc60 kernel/printk/printk.c:3176

stack backtrace:
CPU: 0 UID: 0 PID: 17087 Comm: syz.5.3052 Not tainted syzkaller #0 PREEMPT(full) 
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+0x275/0x350 kernel/locking/lockdep.c:2043
 check_noncircular+0x14c/0x170 kernel/locking/lockdep.c:2175
 check_prev_add kernel/locking/lockdep.c:3165 [inline]
 check_prevs_add kernel/locking/lockdep.c:3284 [inline]
 validate_chain kernel/locking/lockdep.c:3908 [inline]
 __lock_acquire+0x12a6/0x1ce0 kernel/locking/lockdep.c:5237
 lock_acquire kernel/locking/lockdep.c:5868 [inline]
 lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5825
 console_lock_spinning_enable+0x72/0x80 kernel/printk/printk.c:1897
 console_emit_next_record kernel/printk/printk.c:3105 [inline]
 console_flush_all+0x7aa/0xc60 kernel/printk/printk.c:3199
 __console_flush_and_unlock kernel/printk/printk.c:3258 [inline]
 console_unlock+0xd8/0x210 kernel/printk/printk.c:3298
 vprintk_emit+0x3d7/0x680 kernel/printk/printk.c:2423
 _printk+0xc7/0x100 kernel/printk/printk.c:2448
 fail_dump lib/fault-inject.c:66 [inline]
 should_fail_ex+0x4e7/0x640 lib/fault-inject.c:174
 strncpy_from_user+0x3b/0x2e0 lib/strncpy_from_user.c:118
 strncpy_from_user_nofault+0x7f/0x180 mm/maccess.c:192
 bpf_trace_copy_string kernel/bpf/helpers.c:764 [inline]
 bpf_bprintf_prepare+0xe90/0x13f0 kernel/bpf/helpers.c:976
 ____bpf_trace_printk kernel/trace/bpf_trace.c:372 [inline]
 bpf_trace_printk+0xda/0x190 kernel/trace/bpf_trace.c:362
 bpf_prog_930ede9872f2967c+0x3e/0x44
 bpf_dispatcher_nop_func include/linux/bpf.h:1350 [inline]
 __bpf_prog_run include/linux/filter.h:721 [inline]
 bpf_prog_run include/linux/filter.h:728 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:2075 [inline]
 bpf_trace_run2+0x236/0x590 kernel/trace/bpf_trace.c:2116
 __bpf_trace_contention_begin+0xc9/0x110 include/trace/events/lock.h:95
 __preempt_count_dec_and_test arch/x86/include/asm/preempt.h:95 [inline]
 class_preempt_notrace_destructor include/linux/preempt.h:471 [inline]
 __do_trace_contention_begin include/trace/events/lock.h:95 [inline]
 trace_contention_begin.constprop.0+0xde/0x160 include/trace/events/lock.h:95
 __pv_queued_spin_lock_slowpath+0x109/0xcf0 kernel/locking/qspinlock.c:219
 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:557 [inline]
 queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:51 [inline]
 queued_spin_lock include/asm-generic/qspinlock.h:114 [inline]
 do_raw_spin_lock+0x20e/0x2b0 kernel/locking/spinlock_debug.c:116
 raw_spin_rq_lock_nested kernel/sched/core.c:646 [inline]
 raw_spin_rq_lock_nested+0x7e/0x130 kernel/sched/core.c:631
 raw_spin_rq_lock kernel/sched/sched.h:1546 [inline]
 rq_lock kernel/sched/sched.h:1868 [inline]
 __schedule+0x307/0x5de0 kernel/sched/core.c:6833
 preempt_schedule_common+0x44/0xc0 kernel/sched/core.c:7113
 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
 vprintk_emit+0x408/0x680 kernel/printk/printk.c:2424
 _printk+0xc7/0x100 kernel/printk/printk.c:2448
 ovs_flow_cmd_new+0x9f3/0xe30 net/openvswitch/datapath.c:1014
 genl_family_rcv_msg_doit+0x209/0x2f0 net/netlink/genetlink.c:1115
 genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline]
 genl_rcv_msg+0x55c/0x800 net/netlink/genetlink.c:1210
 netlink_rcv_skb+0x158/0x420 net/netlink/af_netlink.c:2552
 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219
 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
 netlink_unicast+0x5a7/0x870 net/netlink/af_netlink.c:1346
 netlink_sendmsg+0x8c8/0xdd0 net/netlink/af_netlink.c:1896
 sock_sendmsg_nosec net/socket.c:727 [inline]
 __sock_sendmsg net/socket.c:742 [inline]
 ____sys_sendmsg+0xa95/0xc70 net/socket.c:2630
 ___sys_sendmsg+0x134/0x1d0 net/socket.c:2684
 __sys_sendmsg+0x16d/0x220 net/socket.c:2716
 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
 __do_fast_syscall_32+0x7c/0x300 arch/x86/entry/syscall_32.c:306
 do_fast_syscall_32+0x32/0x80 arch/x86/entry/syscall_32.c:331
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf70be579
Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00
RSP: 002b:00000000f54ae55c EFLAGS: 00000296 ORIG_RAX: 0000000000000172
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000080000000
RDX: 000000000000c000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
CPU: 0 UID: 0 PID: 17087 Comm: syz.5.3052 Not tainted syzkaller #0 PREEMPT(full) 
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+0x512/0x640 lib/fault-inject.c:174
 strncpy_from_user+0x3b/0x2e0 lib/strncpy_from_user.c:118
 strncpy_from_user_nofault+0x7f/0x180 mm/maccess.c:192
 bpf_trace_copy_string kernel/bpf/helpers.c:764 [inline]
 bpf_bprintf_prepare+0xe90/0x13f0 kernel/bpf/helpers.c:976
 ____bpf_trace_printk kernel/trace/bpf_trace.c:372 [inline]
 bpf_trace_printk+0xda/0x190 kernel/trace/bpf_trace.c:362
 bpf_prog_930ede9872f2967c+0x3e/0x44
 bpf_dispatcher_nop_func include/linux/bpf.h:1350 [inline]
 __bpf_prog_run include/linux/filter.h:721 [inline]
 bpf_prog_run include/linux/filter.h:728 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:2075 [inline]
 bpf_trace_run2+0x236/0x590 kernel/trace/bpf_trace.c:2116
 __bpf_trace_contention_begin+0xc9/0x110 include/trace/events/lock.h:95
 __preempt_count_dec_and_test arch/x86/include/asm/preempt.h:95 [inline]
 class_preempt_notrace_destructor include/linux/preempt.h:471 [inline]
 __do_trace_contention_begin include/trace/events/lock.h:95 [inline]
 trace_contention_begin.constprop.0+0xde/0x160 include/trace/events/lock.h:95
 __pv_queued_spin_lock_slowpath+0x109/0xcf0 kernel/locking/qspinlock.c:219
 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:557 [inline]
 queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:51 [inline]
 queued_spin_lock include/asm-generic/qspinlock.h:114 [inline]
 do_raw_spin_lock+0x20e/0x2b0 kernel/locking/spinlock_debug.c:116
 raw_spin_rq_lock_nested kernel/sched/core.c:646 [inline]
 raw_spin_rq_lock_nested+0x7e/0x130 kernel/sched/core.c:631
 raw_spin_rq_lock kernel/sched/sched.h:1546 [inline]
 rq_lock kernel/sched/sched.h:1868 [inline]
 __schedule+0x307/0x5de0 kernel/sched/core.c:6833
 preempt_schedule_common+0x44/0xc0 kernel/sched/core.c:7113
 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
 vprintk_emit+0x408/0x680 kernel/printk/printk.c:2424
 _printk+0xc7/0x100 kernel/printk/printk.c:2448
 ovs_flow_cmd_new+0x9f3/0xe30 net/openvswitch/datapath.c:1014
 genl_family_rcv_msg_doit+0x209/0x2f0 net/netlink/genetlink.c:1115
 genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline]
 genl_rcv_msg+0x55c/0x800 net/netlink/genetlink.c:1210
 netlink_rcv_skb+0x158/0x420 net/netlink/af_netlink.c:2552
 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219
 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
 netlink_unicast+0x5a7/0x870 net/netlink/af_netlink.c:1346
 netlink_sendmsg+0x8c8/0xdd0 net/netlink/af_netlink.c:1896
 sock_sendmsg_nosec net/socket.c:727 [inline]
 __sock_sendmsg net/socket.c:742 [inline]
 ____sys_sendmsg+0xa95/0xc70 net/socket.c:2630
 ___sys_sendmsg+0x134/0x1d0 net/socket.c:2684
 __sys_sendmsg+0x16d/0x220 net/socket.c:2716
 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
 __do_fast_syscall_32+0x7c/0x300 arch/x86/entry/syscall_32.c:306
 do_fast_syscall_32+0x32/0x80 arch/x86/entry/syscall_32.c:331
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf70be579
Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00
RSP: 002b:00000000f54ae55c EFLAGS: 00000296 ORIG_RAX: 0000000000000172
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000080000000
RDX: 000000000000c000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
----------------
Code disassembly (best guess), 2 bytes skipped:
   0:	10 06                	adc    %al,(%rsi)
   2:	03 74 b4 01          	add    0x1(%rsp,%rsi,4),%esi
   6:	10 07                	adc    %al,(%rdi)
   8:	03 74 b0 01          	add    0x1(%rax,%rsi,4),%esi
   c:	10 08                	adc    %cl,(%rax)
   e:	03 74 d8 01          	add    0x1(%rax,%rbx,8),%esi
  1e:	00 51 52             	add    %dl,0x52(%rcx)
  21:	55                   	push   %rbp
  22:	89 e5                	mov    %esp,%ebp
  24:	0f 34                	sysenter
  26:	cd 80                	int    $0x80
* 28:	5d                   	pop    %rbp <-- trapping instruction
  29:	5a                   	pop    %rdx
  2a:	59                   	pop    %rcx
  2b:	c3                   	ret
  2c:	90                   	nop
  2d:	90                   	nop
  2e:	90                   	nop
  2f:	90                   	nop
  30:	8d b4 26 00 00 00 00 	lea    0x0(%rsi,%riz,1),%esi
  37:	8d b4 26 00 00 00 00 	lea    0x0(%rsi,%riz,1),%esi