INFO: task syz.8.8750:2946 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.8.8750 state:D stack:26400 pid: 2946 ppid: 32737 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11bb/0x4390 kernel/sched/core.c:6395
schedule+0x11b/0x1e0 kernel/sched/core.c:6478
perf_pending_task_sync+0x13c/0x1c0 kernel/events/core.c:5127
_free_event+0x34/0xe60 kernel/events/core.c:5133
put_event kernel/events/core.c:5258 [inline]
perf_event_release_kernel+0x832/0x8c0 kernel/events/core.c:5383
perf_release+0x37/0x40 kernel/events/core.c:5393
__fput+0x234/0x930 fs/file_table.c:311
task_work_run+0x125/0x1a0 kernel/task_work.c:188
exit_task_work include/linux/task_work.h:33 [inline]
do_exit+0x61e/0x20a0 kernel/exit.c:883
do_group_exit+0x12e/0x300 kernel/exit.c:997
get_signal+0x6ca/0x12c0 kernel/signal.c:2900
arch_do_signal_or_restart+0xc1/0x1300 arch/x86/kernel/signal.c:867
handle_signal_work kernel/entry/common.c:154 [inline]
exit_to_user_mode_loop+0x9e/0x130 kernel/entry/common.c:178
exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214
__syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307
do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f1d3207dba9
RSP: 002b:00007f1d302e50e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: 0000000000000000 RBX: 00007f1d322c4fa8 RCX: 00007f1d3207dba9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f1d322c4fa8
RBP: 00007f1d322c4fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f1d322c5038 R14: 00007fff37ac9350 R15: 00007fff37ac9438
Showing all locks held in the system:
1 lock held by khungtaskd/27:
#0: ffffffff8c11c660 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
4 locks held by kworker/u4:4/3062:
2 locks held by getty/3951:
#0: ffff88802c0df098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
#1: ffffc90002cf62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5ba/0x1a30 drivers/tty/n_tty.c:2158
2 locks held by kworker/1:22/28660:
#0: ffff888016872138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1
#1: ffffc900033cfd00 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285
4 locks held by kworker/u4:1/30533:
#0: ffff8880169cd938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1
#1: ffffc90002d5fd00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285
#2: ffffffff8d22c3d0 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x132/0xb80 net/core/net_namespace.c:589
#3: ffffffff8d238048 (rtnl_mutex){+.+.}-{3:3}, at: ipmr_rules_exit+0x25/0x1e0 net/ipv4/ipmr.c:276
3 locks held by kworker/0:70/3139:
#0: ffff888016870938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1
#1: ffffc9000420fd00 (fqdir_free_work){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285
#2: ffffffff8c120ff0 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0xa1/0x4b0 kernel/rcu/tree.c:4043
1 lock held by syz-executor/7018:
#0: ffffffff8d238048 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
#0: ffffffff8d238048 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x974/0xe60 net/core/rtnetlink.c:5647
2 locks held by syz.8.9844/7062:
#0: ffffffff8d238048 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:699 [inline]
#0: ffffffff8d238048 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x3d/0x1b0 drivers/net/tun.c:3440
#1: ffffffff8c1210e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline]
#1: ffffffff8c1210e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x347/0x6b0 kernel/rcu/tree_exp.h:845
1 lock held by syz.8.9844/7063:
1 lock held by syz.1.9847/7080:
#0: ffffffff8d238048 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:699 [inline]
#0: ffffffff8d238048 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x3d/0x1b0 drivers/net/tun.c:3440
=============================================
NMI backtrace for cpu 1
CPU: 1 PID: 27 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106
nmi_cpu_backtrace+0x397/0x3d0 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline]
watchdog+0xe0f/0xe50 kernel/hung_task.c:369
kthread+0x436/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:schedule_debug kernel/sched/core.c:5601 [inline]
RIP: 0010:__schedule+0x138/0x4390 kernel/sched/core.c:6286
Code: 74 08 48 89 df e8 68 43 0b f8 48 8b 1b 48 89 d8 48 c1 e8 03 42 80 3c 28 00 74 08 48 89 df e8 4f 43 0b f8 48 81 3b 9d 6e ac 57 <0f> 85 53 13 00 00 83 7c 24 50 00 75 42 49 8d 5f 18 48 89 d8 48 c1
RSP: 0018:ffffffff8be07be0 EFLAGS: 00000246
RAX: 1ffffffff17c0000 RBX: ffffffff8be00000 RCX: 0000000000000000
RDX: 0000000000000010 RSI: 0000000000000000 RDI: ffffffff8be07d50
RBP: ffffffff8be07db0 R08: dffffc0000000000 R09: ffffffff8be07d40
R10: fffffbfff17c0faa R11: 1ffffffff17c0fa8 R12: ffffffff8be07d40
R13: dffffc0000000000 R14: ffff8880b9000000 R15: ffffffff8bebc3c0
FS: 0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fce85972ad8 CR3: 000000007e487000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000200000000300 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
schedule_idle+0x4a/0x90 kernel/sched/core.c:6506
do_idle+0x556/0x5b0 kernel/sched/idle.c:334
cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:403
start_kernel+0x486/0x530 init/main.c:1140
secondary_startup_64_no_verify+0xb1/0xbb