======================================================
WARNING: possible circular locking dependency detected
4.15.0-rc3+ #219 Not tainted
------------------------------------------------------
syz-executor4/13206 is trying to acquire lock:
 (&ctx->mutex){+.+.}, at: [<0000000005e7c89b>] perf_event_ctx_lock_nested+0x21b/0x450 kernel/events/core.c:1249

but task is already holding lock:
 (&pipe->mutex/1){+.+.}, at: [<00000000c7d0f4d1>] pipe_lock_nested fs/pipe.c:67 [inline]
 (&pipe->mutex/1){+.+.}, at: [<00000000c7d0f4d1>] pipe_lock+0x56/0x70 fs/pipe.c:75

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #8 (&pipe->mutex/1){+.+.}:
       lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:4004
       __mutex_lock_common kernel/locking/mutex.c:756 [inline]
       __mutex_lock+0x16f/0x1a80 kernel/locking/mutex.c:893
       mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908
       pipe_lock_nested fs/pipe.c:67 [inline]
       pipe_lock+0x56/0x70 fs/pipe.c:75
       iter_file_splice_write+0x264/0xf30 fs/splice.c:699
       do_splice_from fs/splice.c:851 [inline]
       do_splice fs/splice.c:1147 [inline]
       SYSC_splice fs/splice.c:1402 [inline]
       SyS_splice+0x7d5/0x1630 fs/splice.c:1382
       entry_SYSCALL_64_fastpath+0x1f/0x96

-> #7 (sb_writers){.+.+}:
       spin_lock include/linux/spinlock.h:315 [inline]
       fast_dput fs/dcache.c:687 [inline]
       dput.part.23+0x492/0x830 fs/dcache.c:794
       dput+0x1f/0x30 fs/dcache.c:787
       handle_remove+0x70c/0xb60 drivers/base/devtmpfs.c:336
       handle drivers/base/devtmpfs.c:375 [inline]
       devtmpfsd+0x262/0x4b0 drivers/base/devtmpfs.c:399
       kthread+0x37a/0x440 kernel/kthread.c:238

-> #6 ((completion)&req.done){+.+.}:
       lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:4004
       complete_acquire include/linux/completion.h:40 [inline]
       __wait_for_common kernel/sched/completion.c:109 [inline]
       wait_for_common kernel/sched/completion.c:123 [inline]
       wait_for_completion+0xcb/0x7b0 kernel/sched/completion.c:144
       devtmpfs_create_node+0x32b/0x4a0 drivers/base/devtmpfs.c:115
       device_add+0x120f/0x1640 drivers/base/core.c:1824
       device_create_groups_vargs+0x1f3/0x250 drivers/base/core.c:2430
       device_create_vargs drivers/base/core.c:2470 [inline]
       device_create+0xda/0x110 drivers/base/core.c:2506
       msr_device_create+0x26/0x40 arch/x86/kernel/msr.c:188
       cpuhp_invoke_callback+0x2ea/0x1d20 kernel/cpu.c:182
       cpuhp_thread_fun+0x48e/0x7e0 kernel/cpu.c:571
       smpboot_thread_fn+0x450/0x7c0 kernel/smpboot.c:164
       kthread+0x37a/0x440 kernel/kthread.c:238
       ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:441

-> #5 (cpuhp_state-up){+.+.}:
       lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:4004
       cpuhp_lock_acquire kernel/cpu.c:85 [inline]
       cpuhp_invoke_ap_callback kernel/cpu.c:605 [inline]
       cpuhp_issue_call+0x1e5/0x520 kernel/cpu.c:1495
       __cpuhp_setup_state_cpuslocked+0x282/0x600 kernel/cpu.c:1642
       __cpuhp_setup_state+0xb0/0x140 kernel/cpu.c:1671
       cpuhp_setup_state include/linux/cpuhotplug.h:201 [inline]
       page_writeback_init+0x4d/0x71 mm/page-writeback.c:2081
       pagecache_init+0x48/0x4f mm/filemap.c:977
       start_kernel+0x6bc/0x74f init/main.c:695
       x86_64_start_reservations+0x2a/0x2c arch/x86/kernel/head64.c:378
       x86_64_start_kernel+0x77/0x7a arch/x86/kernel/head64.c:359
       secondary_startup_64+0xa5/0xb0 arch/x86/kernel/head_64.S:237

-> #4 (cpuhp_state_mutex){+.+.}:
       lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:4004
       __mutex_lock_common kernel/locking/mutex.c:756 [inline]
       __mutex_lock+0x16f/0x1a80 kernel/locking/mutex.c:893
       mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908
       __cpuhp_setup_state_cpuslocked+0x5b/0x600 kernel/cpu.c:1617
       __cpuhp_setup_state+0xb0/0x140 kernel/cpu.c:1671
       cpuhp_setup_state_nocalls include/linux/cpuhotplug.h:229 [inline]
       kvm_guest_init+0x1f3/0x20f arch/x86/kernel/kvm.c:528
       setup_arch+0x17e8/0x1a02 arch/x86/kernel/setup.c:1266
       start_kernel+0xa5/0x74f init/main.c:530
       x86_64_start_reservations+0x2a/0x2c arch/x86/kernel/head64.c:378
       x86_64_start_kernel+0x77/0x7a arch/x86/kernel/head64.c:359
       secondary_startup_64+0xa5/0xb0 arch/x86/kernel/head_64.S:237

-> #3 (cpu_hotplug_lock.rw_sem){++++}:
       lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:4004
       percpu_down_read_preempt_disable include/linux/percpu-rwsem.h:36 [inline]
       percpu_down_read include/linux/percpu-rwsem.h:59 [inline]
       cpus_read_lock+0x42/0x90 kernel/cpu.c:293
       static_key_slow_inc+0x9d/0x3c0 kernel/jump_label.c:123
       tracepoint_add_func kernel/tracepoint.c:223 [inline]
       tracepoint_probe_register_prio+0x80d/0x9a0 kernel/tracepoint.c:283
       tracepoint_probe_register+0x2a/0x40 kernel/tracepoint.c:304
       trace_event_reg+0x167/0x320 kernel/trace/trace_events.c:305
       perf_trace_event_reg kernel/trace/trace_event_perf.c:122 [inline]
       perf_trace_event_init kernel/trace/trace_event_perf.c:197 [inline]
       perf_trace_init+0x4ef/0xab0 kernel/trace/trace_event_perf.c:221
       perf_tp_event_init+0x7d/0xf0 kernel/events/core.c:7956
       perf_try_init_event+0xc9/0x1f0 kernel/events/core.c:9182
       perf_init_event kernel/events/core.c:9220 [inline]
       perf_event_alloc+0x1cc6/0x2b00 kernel/events/core.c:9484
       SYSC_perf_event_open+0x842/0x2f10 kernel/events/core.c:9939
       SyS_perf_event_open+0x39/0x50 kernel/events/core.c:9825
       entry_SYSCALL_64_fastpath+0x1f/0x96

-> #2 (tracepoints_mutex){+.+.}:
       lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:4004
       __mutex_lock_common kernel/locking/mutex.c:756 [inline]
       __mutex_lock+0x16f/0x1a80 kernel/locking/mutex.c:893
       mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908
       tracepoint_probe_register_prio+0xa0/0x9a0 kernel/tracepoint.c:279
       tracepoint_probe_register+0x2a/0x40 kernel/tracepoint.c:304
       trace_event_reg+0x167/0x320 kernel/trace/trace_events.c:305
       perf_trace_event_reg kernel/trace/trace_event_perf.c:122 [inline]
       perf_trace_event_init kernel/trace/trace_event_perf.c:197 [inline]
       perf_trace_init+0x4ef/0xab0 kernel/trace/trace_event_perf.c:221
       perf_tp_event_init+0x7d/0xf0 kernel/events/core.c:7956
       perf_try_init_event+0xc9/0x1f0 kernel/events/core.c:9182
       perf_init_event kernel/events/core.c:9220 [inline]
       perf_event_alloc+0x1cc6/0x2b00 kernel/events/core.c:9484
       SYSC_perf_event_open+0x842/0x2f10 kernel/events/core.c:9939
       SyS_perf_event_open+0x39/0x50 kernel/events/core.c:9825
       entry_SYSCALL_64_fastpath+0x1f/0x96

-> #1 (event_mutex){+.+.}:
       lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:4004
       __mutex_lock_common kernel/locking/mutex.c:756 [inline]
       __mutex_lock+0x16f/0x1a80 kernel/locking/mutex.c:893
       mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908
       perf_trace_init+0x58/0xab0 kernel/trace/trace_event_perf.c:216
       perf_tp_event_init+0x7d/0xf0 kernel/events/core.c:7956
       perf_try_init_event+0xc9/0x1f0 kernel/events/core.c:9182
       perf_init_event kernel/events/core.c:9204 [inline]
       perf_event_alloc+0x1005/0x2b00 kernel/events/core.c:9484
       inherit_event.isra.92+0x15b/0x920 kernel/events/core.c:10698
       inherit_group kernel/events/core.c:10789 [inline]
       inherit_task_group.isra.94.part.95+0x73/0x240 kernel/events/core.c:10847
       inherit_task_group kernel/events/core.c:10827 [inline]
       perf_event_init_context kernel/events/core.c:10898 [inline]
       perf_event_init_task+0x348/0x890 kernel/events/core.c:10966
       copy_process.part.36+0x173b/0x4ae0 kernel/fork.c:1727
       copy_process kernel/fork.c:1566 [inline]
       _do_fork+0x1ef/0xff0 kernel/fork.c:2045
       SYSC_clone kernel/fork.c:2155 [inline]
       SyS_clone+0x37/0x50 kernel/fork.c:2149
       do_syscall_64+0x26c/0x920 arch/x86/entry/common.c:285
       return_from_SYSCALL_64+0x0/0x75

-> #0 (&ctx->mutex){+.+.}:
       check_prevs_add kernel/locking/lockdep.c:2031 [inline]
       validate_chain kernel/locking/lockdep.c:2473 [inline]
       __lock_acquire+0x3498/0x47f0 kernel/locking/lockdep.c:3500
       lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:4004
       __mutex_lock_common kernel/locking/mutex.c:756 [inline]
       __mutex_lock+0x16f/0x1a80 kernel/locking/mutex.c:893
       mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908
       perf_event_ctx_lock_nested+0x21b/0x450 kernel/events/core.c:1249
       perf_event_ctx_lock kernel/events/core.c:1262 [inline]
       perf_read+0xb9/0x970 kernel/events/core.c:4507
       do_loop_readv_writev fs/read_write.c:673 [inline]
       do_iter_read+0x3db/0x5b0 fs/read_write.c:897
       vfs_readv+0x121/0x1c0 fs/read_write.c:959
       kernel_readv fs/splice.c:361 [inline]
       default_file_splice_read+0x508/0xae0 fs/splice.c:416
       do_splice_to+0x110/0x170 fs/splice.c:880
       do_splice fs/splice.c:1173 [inline]
       SYSC_splice fs/splice.c:1402 [inline]
       SyS_splice+0x11a8/0x1630 fs/splice.c:1382
       entry_SYSCALL_64_fastpath+0x1f/0x96

other info that might help us debug this:

Chain exists of:
  &ctx->mutex --> sb_writers --> &pipe->mutex/1

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&pipe->mutex/1);
                               lock(sb_writers);
                               lock(&pipe->mutex/1);
  lock(&ctx->mutex);

 *** DEADLOCK ***

1 lock held by syz-executor4/13206:
 #0:  (&pipe->mutex/1){+.+.}, at: [<00000000c7d0f4d1>] pipe_lock_nested fs/pipe.c:67 [inline]
 #0:  (&pipe->mutex/1){+.+.}, at: [<00000000c7d0f4d1>] pipe_lock+0x56/0x70 fs/pipe.c:75

stack backtrace:
CPU: 0 PID: 13206 Comm: syz-executor4 Not tainted 4.15.0-rc3+ #219
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x194/0x257 lib/dump_stack.c:53
 print_circular_bug+0x42d/0x610 kernel/locking/lockdep.c:1271
 check_prev_add+0x666/0x15f0 kernel/locking/lockdep.c:1914
 check_prevs_add kernel/locking/lockdep.c:2031 [inline]
 validate_chain kernel/locking/lockdep.c:2473 [inline]
 __lock_acquire+0x3498/0x47f0 kernel/locking/lockdep.c:3500
 lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:4004
 __mutex_lock_common kernel/locking/mutex.c:756 [inline]
 __mutex_lock+0x16f/0x1a80 kernel/locking/mutex.c:893
 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908
 perf_event_ctx_lock_nested+0x21b/0x450 kernel/events/core.c:1249
 perf_event_ctx_lock kernel/events/core.c:1262 [inline]
 perf_read+0xb9/0x970 kernel/events/core.c:4507
 do_loop_readv_writev fs/read_write.c:673 [inline]
 do_iter_read+0x3db/0x5b0 fs/read_write.c:897
 vfs_readv+0x121/0x1c0 fs/read_write.c:959
 kernel_readv fs/splice.c:361 [inline]
 default_file_splice_read+0x508/0xae0 fs/splice.c:416
 do_splice_to+0x110/0x170 fs/splice.c:880
 do_splice fs/splice.c:1173 [inline]
 SYSC_splice fs/splice.c:1402 [inline]
 SyS_splice+0x11a8/0x1630 fs/splice.c:1382
 entry_SYSCALL_64_fastpath+0x1f/0x96
RIP: 0033:0x452a39
RSP: 002b:00007ff54e326c58 EFLAGS: 00000212 ORIG_RAX: 0000000000000113
RAX: ffffffffffffffda RBX: 0000000000758020 RCX: 0000000000452a39
RDX: 0000000000000017 RSI: 0000000000000000 RDI: 0000000000000018
RBP: 00000000000001f7 R08: 0000000100000001 R09: 000000000000000e
R10: 0000000000000000 R11: 0000000000000212 R12: 00000000006f0fc8
R13: 00000000ffffffff R14: 00007ff54e3276d4 R15: 0000000000000000
netlink: 'syz-executor0': attribute type 1 has an invalid length.
netlink: 'syz-executor0': attribute type 1 has an invalid length.
binder: 13265:13273 ioctl 40106410 20926ff0 returned -22
binder: 13265:13267 tried to acquire reference to desc 0, got 1 instead
binder: 13265:13267 ioctl ae03 2 returned -22
binder: BINDER_SET_CONTEXT_MGR already set
binder: 13265:13295 ioctl 40046207 0 returned -16
binder: BINDER_SET_CONTEXT_MGR already set
binder: 13265:13292 ioctl 40046207 0 returned -16
binder: 13265:13292 ioctl 40106410 20926ff0 returned -22
binder: 13265:13292 ioctl ae03 2 returned -22
Started in network mode
Own node address <224.1700.2439>, network identity 4711
kauditd_printk_skb: 1218 callbacks suppressed
audit: type=1326 audit(1513131162.715:9191): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 pid=13376 comm="syz-executor5" exe="/root/syz-executor5" sig=0 arch=c000003e syscall=190 compat=0 ip=0x452a39 code=0x7ffc0000
Started in network mode
Own node address <64.1656.2950>, network identity 4711
sg_write: data in/out 156/14 bytes for SCSI command 0x85-- guessing data in;
   program syz-executor7 not setting count and/or reply_len properly
netlink: 8 bytes leftover after parsing attributes in process `syz-executor1'.
audit: type=1326 audit(1513131162.715:9192): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 pid=13376 comm="syz-executor5" exe="/root/syz-executor5" sig=0 arch=c000003e syscall=202 compat=0 ip=0x452a39 code=0x7ffc0000
audit: type=1326 audit(1513131162.715:9193): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 pid=13376 comm="syz-executor5" exe="/root/syz-executor5" sig=0 arch=c000003e syscall=202 compat=0 ip=0x452a39 code=0x7ffc0000
audit: type=1326 audit(1513131162.716:9194): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 pid=13376 comm="syz-executor5" exe="/root/syz-executor5" sig=0 arch=c000003e syscall=330 compat=0 ip=0x452a39 code=0x7ffc0000
audit: type=1326 audit(1513131162.716:9195): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 pid=13376 comm="syz-executor5" exe="/root/syz-executor5" sig=0 arch=c000003e syscall=202 compat=0 ip=0x452a39 code=0x7ffc0000
audit: type=1326 audit(1513131162.717:9196): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 pid=13376 comm="syz-executor5" exe="/root/syz-executor5" sig=0 arch=c000003e syscall=202 compat=0 ip=0x452a39 code=0x7ffc0000
audit: type=1326 audit(1513131162.717:9197): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 pid=13376 comm="syz-executor5" exe="/root/syz-executor5" sig=0 arch=c000003e syscall=41 compat=0 ip=0x452a39 code=0x7ffc0000
audit: type=1326 audit(1513131162.717:9198): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 pid=13376 comm="syz-executor5" exe="/root/syz-executor5" sig=0 arch=c000003e syscall=202 compat=0 ip=0x452a39 code=0x7ffc0000
audit: type=1326 audit(1513131162.717:9199): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 pid=13376 comm="syz-executor5" exe="/root/syz-executor5" sig=0 arch=c000003e syscall=202 compat=0 ip=0x452a39 code=0x7ffc0000
audit: type=1326 audit(1513131162.718:9200): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 pid=13376 comm="syz-executor5" exe="/root/syz-executor5" sig=0 arch=c000003e syscall=331 compat=0 ip=0x452a39 code=0x7ffc0000
netlink: 8 bytes leftover after parsing attributes in process `syz-executor1'.
sg_write: data in/out 156/14 bytes for SCSI command 0x85-- guessing data in;
   program syz-executor7 not setting count and/or reply_len properly
sg_write: data in/out 156/14 bytes for SCSI command 0x85-- guessing data in;
   program syz-executor7 not setting count and/or reply_len properly
sg_write: data in/out 156/14 bytes for SCSI command 0x85-- guessing data in;
   program syz-executor7 not setting count and/or reply_len properly
sg_write: data in/out 156/14 bytes for SCSI command 0x85-- guessing data in;
   program syz-executor7 not setting count and/or reply_len properly
sg_write: data in/out 156/14 bytes for SCSI command 0x85-- guessing data in;
   program syz-executor7 not setting count and/or reply_len properly
sg_write: data in/out 156/14 bytes for SCSI command 0x85-- guessing data in;
   program syz-executor7 not setting count and/or reply_len properly
sg_write: data in/out 156/14 bytes for SCSI command 0x85-- guessing data in;
   program syz-executor7 not setting count and/or reply_len properly
sg_write: data in/out 156/14 bytes for SCSI command 0x85-- guessing data in;
   program syz-executor7 not setting count and/or reply_len properly
Started in network mode
Own node address <64.1656.2950>, network identity 4711
sg_write: data in/out 156/14 bytes for SCSI command 0x85-- guessing data in;
   program syz-executor7 not setting count and/or reply_len properly
Started in network mode
Own node address <101.1878.1395>, network identity 4711
FAULT_INJECTION: forcing a failure.
name failslab, interval 1, probability 0, space 0, times 0
CPU: 0 PID: 14399 Comm: syz-executor0 Not tainted 4.15.0-rc3+ #219
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x194/0x257 lib/dump_stack.c:53
 fail_dump lib/fault-inject.c:51 [inline]
 should_fail+0x8c0/0xa40 lib/fault-inject.c:149
 should_failslab+0xec/0x120 mm/failslab.c:32
 slab_pre_alloc_hook mm/slab.h:421 [inline]
 slab_alloc_node mm/slab.c:3292 [inline]
 kmem_cache_alloc_node+0x56/0x760 mm/slab.c:3635
 __alloc_skb+0xf1/0x780 net/core/skbuff.c:193
 alloc_skb include/linux/skbuff.h:983 [inline]
 netlink_alloc_large_skb net/netlink/af_netlink.c:1144 [inline]
 netlink_sendmsg+0xa86/0xe70 net/netlink/af_netlink.c:1836
 sock_sendmsg_nosec net/socket.c:636 [inline]
 sock_sendmsg+0xca/0x110 net/socket.c:646
 sock_write_iter+0x320/0x5e0 net/socket.c:915
 call_write_iter include/linux/fs.h:1772 [inline]
 new_sync_write fs/read_write.c:469 [inline]
 __vfs_write+0x68a/0x970 fs/read_write.c:482
 vfs_write+0x18f/0x510 fs/read_write.c:544
 SYSC_write fs/read_write.c:589 [inline]
 SyS_write+0xef/0x220 fs/read_write.c:581
 entry_SYSCALL_64_fastpath+0x1f/0x96
RIP: 0033:0x452a39
RSP: 002b:00007fc147a4cc58 EFLAGS: 00000212 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fc147a4caa0 RCX: 0000000000452a39
RDX: 0000000000000020 RSI: 00000000205b9fe0 RDI: 0000000000000013
RBP: 00007fc147a4ca90 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000212 R12: 00000000004b75fb
R13: 00007fc147a4cbc8 R14: 00000000004b75fb R15: 0000000000000000
Started in network mode
Own node address <224.1700.2439>, network identity 4711
SELinux: unrecognized netlink message: protocol=0 nlmsg_type=2329 sclass=netlink_route_socket pig=15040 comm=syz-executor0
SELinux: unrecognized netlink message: protocol=0 nlmsg_type=2329 sclass=netlink_route_socket pig=15046 comm=syz-executor0
FAULT_INJECTION: forcing a failure.
name failslab, interval 1, probability 0, space 0, times 0
CPU: 1 PID: 15477 Comm: syz-executor2 Not tainted 4.15.0-rc3+ #219
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x194/0x257 lib/dump_stack.c:53
 fail_dump lib/fault-inject.c:51 [inline]
 should_fail+0x8c0/0xa40 lib/fault-inject.c:149
FAULT_INJECTION: forcing a failure.
name failslab, interval 1, probability 0, space 0, times 0
 should_failslab+0xec/0x120 mm/failslab.c:32
 slab_pre_alloc_hook mm/slab.h:421 [inline]
 slab_alloc_node mm/slab.c:3292 [inline]
 kmem_cache_alloc_node+0x56/0x760 mm/slab.c:3635
 __alloc_skb+0xf1/0x780 net/core/skbuff.c:193
 alloc_skb include/linux/skbuff.h:983 [inline]
 netlink_alloc_large_skb net/netlink/af_netlink.c:1144 [inline]
 netlink_sendmsg+0xa86/0xe70 net/netlink/af_netlink.c:1836