syzbot

INFO: task syz.0.1020:6582 blocked for more than 143 seconds.
      Not tainted 5.15.189-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.1020      state:D stack:24096 pid: 6582 ppid:  5752 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5030 [inline]
 __schedule+0x11b8/0x43b0 kernel/sched/core.c:6376
 schedule+0x11b/0x1e0 kernel/sched/core.c:6459
 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
 tracehook_notify_resume include/linux/tracehook.h:189 [inline]
 exit_to_user_mode_loop+0x10f/0x130 kernel/entry/common.c:181
 exit_to_user_mode_prepare+0xb1/0x140 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: 0033:0x7f498528bbe9
RSP: 002b:00007ffdd0f92b98 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 0000000000032713 RCX: 00007f498528bbe9
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000001 R09: 00000003d0f92e8f
R10: 0000001b33720000 R11: 0000000000000246 R12: 00007f49854b2fac
R13: 00007f49854b2fa0 R14: ffffffffffffffff R15: 0000000000000003
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffffffff8c11c360 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
4 locks held by kworker/u4:3/729:
 #0: ffff8880169cd938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1
 #1: ffffc9000393fd00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285
 #2: ffffffff8d22a2d0 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x132/0xb80 net/core/net_namespace.c:589
 #3: ffffffff8c120cf0 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0xa1/0x4b0 kernel/rcu/tree.c:4043
2 locks held by getty/3949:
 #0: ffff88802be40098 (&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/0:102/4631:
 #0: ffff888016872138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1
 #1: ffffc90004c87d00 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285
1 lock held by syz.2.2187/9013:
 #0: ffffffff8c120de8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline]
 #0: ffffffff8c120de8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x347/0x6b0 kernel/rcu/tree_exp.h:845

=============================================

NMI backtrace for cpu 1
CPU: 1 PID: 27 Comm: khungtaskd Not tainted 5.15.189-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
 <TASK>
 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
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 1215 Comm: kworker/u4:4 Not tainted 5.15.189-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Workqueue: phy13 ieee80211_iface_work
RIP: 0010:update_rq_clock_pelt kernel/sched/pelt.h:-1 [inline]
RIP: 0010:update_rq_clock_task kernel/sched/core.c:664 [inline]
RIP: 0010:update_rq_clock+0x267/0x450 kernel/sched/core.c:686
Code: e8 ae a7 6a 00 4d 8b 3f 49 83 c7 2c 4c 89 f8 48 c1 e8 03 42 0f b6 04 28 84 c0 0f 85 9c 01 00 00 41 f6 07 02 0f 85 af 00 00 00 <48> 8b 44 24 08 42 0f b6 04 28 84 c0 0f 85 9e 01 00 00 48 8b 04 24
RSP: 0018:ffffc90004cc7b78 EFLAGS: 00000046
RAX: 0000000000000000 RBX: ffff8880b903a300 RCX: dffffc0000000000
RDX: 1ffff110172075db RSI: 0000000000001977 RDI: ffff8880b903aed0
RBP: 00000000000047a6 R08: ffffffff8eecc008 R09: ffffffff8eecc018
R10: ffffffff8eecc010 R11: ffffffff8eecc003 R12: ffff8880b903ad80
R13: dffffc0000000000 R14: 000000020b336a42 R15: ffff8880218cd96c
FS:  0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 00000000243cc000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 ttwu_queue kernel/sched/core.c:3822 [inline]
 try_to_wake_up+0x604/0x1050 kernel/sched/core.c:4146
 wake_up_worker kernel/workqueue.c:859 [inline]
 process_one_work+0x69c/0x1000 kernel/workqueue.c:2273
 worker_thread+0xaa8/0x12a0 kernel/workqueue.c:2457
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>