INFO: task syz.3.948:7246 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.948 state:D stack:25968 pid:7246 ppid:4265 flags:0x00004006
Call Trace:
context_switch kernel/sched/core.c:5245 [inline]
__schedule+0x11d1/0x40e0 kernel/sched/core.c:6562
schedule+0xb9/0x180 kernel/sched/core.c:6638
perf_pending_task_sync kernel/events/core.c:5031 [inline]
_free_event+0x171/0x10a0 kernel/events/core.c:5037
put_event kernel/events/core.c:5162 [inline]
perf_event_release_kernel+0x83e/0x8d0 kernel/events/core.c:5287
perf_release+0x37/0x40 kernel/events/core.c:5297
__fput+0x22c/0x920 fs/file_table.c:320
task_work_run+0x1d0/0x260 kernel/task_work.c:203
exit_task_work include/linux/task_work.h:39 [inline]
do_exit+0x982/0x2480 kernel/exit.c:880
do_group_exit+0x217/0x2d0 kernel/exit.c:1022
get_signal+0x1272/0x1350 kernel/signal.c:2871
arch_do_signal_or_restart+0xc4/0x1350 arch/x86/kernel/signal.c:871
exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210
__syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303
do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:82
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7ff7a99bc350
RSP: 002b:00007ff7aa908a78 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 00007ff7a9c15fa0 RCX: 00007ff7a999cdd9
RDX: 00007ff7aa908a80 RSI: 00007ff7aa908bb0 RDI: 0000000000000021
RBP: 00007ff7a9a32d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff7a9c16038 R14: 00007ff7a9c15fa0 R15: 00007ffe7f66cdb8
Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
#0: ffffffff8cb2df70 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517
1 lock held by rcu_tasks_trace/13:
#0: ffffffff8cb2e790 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517
1 lock held by khungtaskd/28:
#0: ffffffff8cb2d5e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
#0: ffffffff8cb2d5e0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
#0: ffffffff8cb2d5e0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513
2 locks held by kworker/u4:2/38:
#0: ffff8880b8f3ab18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:538
#1: ffffffff8cb2d5e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
#1: ffffffff8cb2d5e0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
#1: ffffffff8cb2d5e0 (rcu_read_lock){....}-{1:2}, at: do_perf_sw_event kernel/events/core.c:9736 [inline]
#1: ffffffff8cb2d5e0 (rcu_read_lock){....}-{1:2}, at: ___perf_sw_event+0x180/0x6e0 kernel/events/core.c:9774
2 locks held by kworker/1:2/126:
#0: ffff888017472138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
#1: ffffc90002da7d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
1 lock held by dhcpcd/3933:
#0: ffffffff8dd47f68 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline]
#0: ffffffff8dd47f68 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x824/0xfc0 net/core/rtnetlink.c:6154
2 locks held by getty/4026:
#0: ffff88802f8c6098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244
#1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x429/0x1390 drivers/tty/n_tty.c:2198
2 locks held by syz.7.1586/9464:
#0: ffffffff8dd47f68 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:698 [inline]
#0: ffffffff8dd47f68 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x3d/0x1b0 drivers/net/tun.c:3492
#1: ffffffff8cb332b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:291 [inline]
#1: ffffffff8cb332b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x2ec/0x890 kernel/rcu/tree_exp.h:962
1 lock held by syz.4.1587/9468:
#0: ffffffff8dd47f68 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:698 [inline]
#0: ffffffff8dd47f68 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x3d/0x1b0 drivers/net/tun.c:3492
1 lock held by syz.5.1592/9483:
#0: ffffffff8dd47f68 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline]
#0: ffffffff8dd47f68 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x824/0xfc0 net/core/rtnetlink.c:6154
2 locks held by syz.6.1597/9489:
#0: ffffffff8cb826a8 (event_mutex){+.+.}-{3:3}, at: perf_trace_destroy+0x2a/0x140 kernel/trace/trace_event_perf.c:239
#1: ffffffff8cb332b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:323 [inline]
#1: ffffffff8cb332b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3c0/0x890 kernel/rcu/tree_exp.h:962
1 lock held by syz.6.1597/9490:
#0: ffffffff8dd47f68 (rtnl_mutex){+.+.}-{3:3}, at: dev_ioctl+0x54d/0xe80 net/core/dev_ioctl.c:571
=============================================
NMI backtrace for cpu 0
CPU: 0 PID: 28 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Call Trace:
dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106
nmi_cpu_backtrace+0x3e6/0x460 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x1d4/0x450 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline]
watchdog+0xeee/0xf30 kernel/hung_task.c:377
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 38 Comm: kworker/u4:2 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Workqueue: events_unbound nsim_dev_trap_report_work
RIP: 0010:native_flush_tlb_one_user+0xb3/0xe0 arch/x86/mm/tlb.c:1185
Code: fc ff df 66 c7 04 30 00 00 48 89 54 24 20 48 89 7c 24 28 31 d2 66 0f 38 82 54 24 20 66 c7 04 30 f8 f8 48 c7 04 24 0e 36 e0 45 <48> c7 04 08 00 00 00 00 65 48 8b 04 25 28 00 00 00 48 3b 44 24 48
RSP: 0018:ffffc90000af7940 EFLAGS: 00000a06
RAX: 1ffff9200015ef28 RBX: ffff88823bcf4000 RCX: dffffc0000000000
RDX: f3f3f8f8f1f10000 RSI: 800000023bcf4163 RDI: ffff88823bcf4000
RBP: ffffc90000af79a0 R08: ffffc90000af799e R09: 1ffffffff2d98abb
R10: dffffc0000000000 R11: fffffbfff2d98abc R12: ffff8880176227a0
R13: 1ffff9200015ef3c R14: dffffc0000000000 R15: 800ffffdc430b162
FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4f2f5ea2f8 CR3: 000000007e074000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
__flush_tlb_one_user arch/x86/include/asm/paravirt.h:81 [inline]
flush_tlb_one_user arch/x86/mm/tlb.c:1189 [inline]
flush_tlb_one_kernel+0x3d/0x50 arch/x86/mm/tlb.c:1151
kfence_protect_page arch/x86/include/asm/kfence.h:86 [inline]
kfence_protect+0x144/0x200 mm/kfence/core.c:237
kfence_guarded_free+0x3cc/0x780 mm/kfence/core.c:512
do_slab_free mm/slub.c:3641 [inline]
slab_free mm/slub.c:3688 [inline]
kmem_cache_free+0x199/0x290 mm/slub.c:3709
nsim_dev_trap_report drivers/net/netdevsim/dev.c:821 [inline]
nsim_dev_trap_report_work+0x76b/0xaf0 drivers/net/netdevsim/dev.c:851
process_one_work+0x8a2/0x1160 kernel/workqueue.c:2292
worker_thread+0xaa2/0x1270 kernel/workqueue.c:2439
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295