INFO: task syz.4.1215:8398 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.1215      state:D stack:22928 pid: 8398 ppid:  4191 flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11ef/0x43c0 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+0x83e/0x8d0 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
 get_signal+0x1222/0x12c0 kernel/signal.c:2672
 arch_do_signal_or_restart+0xe7/0x12c0 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: 0033:0x7f07c18dfdd9
RSP: 002b:00007f07bfb38fd8 EFLAGS: 00000206 ORIG_RAX: 0000000000000038
RAX: fffffffffffffffc RBX: 00007f07c1b58fa0 RCX: 00007f07c18dfdd9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000004eb82000
RBP: 00007f07c1975d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007f07c1b59038 R14: 00007f07c1b58fa0 R15: 00007ffd92b41af8
 </TASK>

Showing all locks held in the system:
3 locks held by kworker/u4:0/9:
1 lock held by khungtaskd/27:
 #0: ffffffff8c31eb20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
2 locks held by getty/3948:
 #0: ffff88802caea098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
 #1: ffffc900025e62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5df/0x1a70 drivers/tty/n_tty.c:2158
2 locks held by kworker/1:24/9317:
 #0: ffff888016c72138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1
 #1: ffffc900044efd00 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285
2 locks held by syz.6.2548/13546:
2 locks held by syz.2.2552/13584:
 #0: ffffffff8c36c228 (event_mutex){+.+.}-{3:3}, at: perf_trace_destroy+0x2a/0x140 kernel/trace/trace_event_perf.c:239
 #1: ffffffff8c3235a8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline]
 #1: ffffffff8c3235a8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x2d1/0x750 kernel/rcu/tree_exp.h:845

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

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 04/18/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x3a2/0x3d0 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: 1110 Comm: kworker/0:2 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Workqueue: events nsim_dev_trap_report_work
RIP: 0010:__orc_find arch/x86/kernel/unwind_orc.c:50 [inline]
RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:178 [inline]
RIP: 0010:unwind_next_frame+0x102f/0x1d90 arch/x86/kernel/unwind_orc.c:448
Code: 03 48 b9 00 00 00 00 00 fc ff df 80 3c 08 00 74 08 4c 89 ff e8 42 27 89 00 4d 89 37 e9 3f 01 00 00 49 89 d7 49 89 d5 4c 89 e0 <4c> 29 e8 48 89 c1 48 c1 f9 02 48 c1 e8 3f 48 01 c8 48 83 e0 fe 4d
RSP: 0018:ffffc90000006928 EFLAGS: 00000293
RAX: ffffffff8d9faa4c RBX: ffffc900000069e8 RCX: ffffffff8d9faa44
RDX: ffffffff8d9faa20 RSI: ffffffff8e0ef188 RDI: 0000000000000001
RBP: ffffffff81c4a8d0 R08: 000000000000000c R09: 0000000000000000
R10: dffffc0000000000 R11: fffff52000000d49 R12: ffffffff8d9faa4c
R13: ffffffff8d9faa44 R14: ffffffff8d9faa40 R15: ffffffff8d9faa40
FS:  0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f1b4a375158 CR3: 0000000063557000 CR4: 00000000003506f0
DR0: 0000200000000300 DR1: 0000200000000300 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 arch_stack_walk+0x10c/0x140 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0xa6/0xf0 kernel/stacktrace.c:122
 save_stack+0x121/0x230 mm/page_owner.c:119
 __set_page_owner+0x41/0x2d0 mm/page_owner.c:181
 prep_new_page mm/page_alloc.c:2426 [inline]
 get_page_from_freelist+0x1bbd/0x1ca0 mm/page_alloc.c:4192
 __alloc_pages+0x1ee/0x480 mm/page_alloc.c:5501
 alloc_slab_page mm/slub.c:1780 [inline]
 allocate_slab mm/slub.c:1917 [inline]
 new_slab+0xc0/0x4b0 mm/slub.c:1980
 ___slab_alloc+0x80a/0xdd0 mm/slub.c:3013
 __slab_alloc mm/slub.c:3100 [inline]
 slab_alloc_node mm/slub.c:3191 [inline]
 __kmalloc_node_track_caller+0x1fc/0x3a0 mm/slub.c:4963
 kmalloc_reserve net/core/skbuff.c:356 [inline]
 __alloc_skb+0x22c/0x750 net/core/skbuff.c:427
 skb_copy+0x139/0x790 net/core/skbuff.c:1595
 mac80211_hwsim_tx_frame_no_nl+0xce0/0x1600 drivers/net/wireless/mac80211_hwsim.c:1569
 mac80211_hwsim_tx+0x742/0xe20 drivers/net/wireless/mac80211_hwsim.c:1673
 drv_tx net/mac80211/driver-ops.h:35 [inline]
 ieee80211_tx_frags+0x3f4/0x8d0 net/mac80211/tx.c:1721
 __ieee80211_tx+0x21b/0x4e0 net/mac80211/tx.c:1775
 ieee80211_tx+0x30f/0x460 net/mac80211/tx.c:1955
 __ieee80211_subif_start_xmit+0x1036/0x3290 net/mac80211/tx.c:4257
 ieee80211_subif_start_xmit+0xed/0x5d0 net/mac80211/tx.c:4396
 __netdev_start_xmit include/linux/netdevice.h:5036 [inline]
 netdev_start_xmit include/linux/netdevice.h:5050 [inline]
 xmit_one net/core/dev.c:3662 [inline]
 dev_hard_start_xmit+0x2a5/0x7e0 net/core/dev.c:3678
 sch_direct_xmit+0x25a/0x4b0 net/sched/sch_generic.c:345
 qdisc_restart net/sched/sch_generic.c:410 [inline]
 __qdisc_run+0xa7e/0x1490 net/sched/sch_generic.c:418
 qdisc_run+0x103/0x2f0 include/net/pkt_sched.h:131
 net_tx_action+0x6d9/0x880 net/core/dev.c:5154
 handle_softirqs+0x339/0x830 kernel/softirq.c:576
 do_softirq+0x142/0x210 kernel/softirq.c:477
 </IRQ>
 <TASK>
 __local_bh_enable_ip+0x180/0x1c0 kernel/softirq.c:401
 spin_unlock_bh include/linux/spinlock.h:409 [inline]
 nsim_dev_trap_report drivers/net/netdevsim/dev.c:736 [inline]
 nsim_dev_trap_report_work+0x7c0/0xb40 drivers/net/netdevsim/dev.c:762
 process_one_work+0x85f/0x1010 kernel/workqueue.c:2310
 worker_thread+0xaa6/0x1290 kernel/workqueue.c:2457
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>