INFO: task syz.0.1641:9575 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.1641      state:D stack:25520 pid:9575  ppid:4270   flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5245 [inline]
 __schedule+0x107f/0x4030 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+0x176/0x1050 kernel/events/core.c:5037
 put_event kernel/events/core.c:5162 [inline]
 perf_event_release_kernel+0x7c4/0x850 kernel/events/core.c:5287
 perf_release+0x37/0x40 kernel/events/core.c:5297
 __fput+0x20a/0x8b0 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+0x9d5/0x2570 kernel/exit.c:881
 do_group_exit+0x229/0x2e0 kernel/exit.c:1024
 __do_sys_exit_group kernel/exit.c:1035 [inline]
 __se_sys_exit_group kernel/exit.c:1033 [inline]
 __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1033
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f16dcb9de99
RSP: 002b:00007f16ddaaff38 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007f16dcc0a3f8 RCX: 00007f16dcb9de99
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001
RBP: 000000000000000e R08: 0000000000000000 R09: 00007f16dce26038
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007f16dce26038 R14: 00007f16dce25fa0 R15: 00007ffdf81a60d8
 </TASK>

Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
 #0: ffffffff8cb2e4f0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xef0 kernel/rcu/tasks.h:517
1 lock held by rcu_tasks_trace/13:
 #0: ffffffff8cb2ed10 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xef0 kernel/rcu/tasks.h:517
1 lock held by khungtaskd/27:
 #0: ffffffff8cb2db60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
 #0: ffffffff8cb2db60 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
 #0: ffffffff8cb2db60 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6527
2 locks held by kworker/0:2/126:
 #0: ffff888017472138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267
 #1: ffffc90002d67d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267
2 locks held by getty/4028:
 #0: ffff88814d998098 (&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+0x41e/0x1360 drivers/tty/n_tty.c:2198
1 lock held by syz.6.2618/12745:
 #0: ffffffff8cb82c88 (event_mutex){+.+.}-{3:3}, at: perf_trace_destroy+0x2a/0x140 kernel/trace/trace_event_perf.c:239
1 lock held by syz.6.2618/12746:
2 locks held by syz.4.2619/12747:
 #0: ffffffff8cb82c88 (event_mutex){+.+.}-{3:3}, at: perf_trace_destroy+0x2a/0x140 kernel/trace/trace_event_perf.c:239
 #1: ffffffff8cb33838 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:291 [inline]
 #1: ffffffff8cb33838 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x2ec/0x890 kernel/rcu/tree_exp.h:962
2 locks held by syz.5.2621/12750:
 #0: ffffffff96c68168 (&pmus_srcu){....}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
 #0: ffffffff96c68168 (&pmus_srcu){....}-{0:0}, at: srcu_read_lock include/linux/srcu.h:165 [inline]
 #0: ffffffff96c68168 (&pmus_srcu){....}-{0:0}, at: perf_init_event kernel/events/core.c:11664 [inline]
 #0: ffffffff96c68168 (&pmus_srcu){....}-{0:0}, at: perf_event_alloc+0xb28/0x21e0 kernel/events/core.c:11990
 #1: ffffffff8cb82c88 (event_mutex){+.+.}-{3:3}, at: perf_uprobe_init+0x11f/0x190 kernel/trace/trace_event_perf.c:335
2 locks held by syz.2.2620/12758:
 #0: ffffffff96c68168 (&pmus_srcu){....}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
 #0: ffffffff96c68168 (&pmus_srcu){....}-{0:0}, at: srcu_read_lock include/linux/srcu.h:165 [inline]
 #0: ffffffff96c68168 (&pmus_srcu){....}-{0:0}, at: perf_init_event kernel/events/core.c:11664 [inline]
 #0: ffffffff96c68168 (&pmus_srcu){....}-{0:0}, at: perf_event_alloc+0xb28/0x21e0 kernel/events/core.c:11990
 #1: ffffffff8cb82c88 (event_mutex){+.+.}-{3:3}, at: perf_trace_init+0x4c/0x2d0 kernel/trace/trace_event_perf.c:221
3 locks held by syz.2.2620/12763:

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

NMI backtrace for cpu 0
CPU: 0 PID: 27 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Call Trace:
 <TASK>
 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+0xf0e/0xf50 kernel/hung_task.c:377
 kthread+0x29d/0x330 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 12763 Comm: syz.2.2620 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:__orc_find arch/x86/kernel/unwind_orc.c:52 [inline]
RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:178 [inline]
RIP: 0010:unwind_next_frame+0x1223/0x1fd0 arch/x86/kernel/unwind_orc.c:448
Code: 8d 7c 45 00 4c 89 f8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 0f b6 04 08 84 c0 75 27 49 63 07 4c 01 f8 49 8d 4f 04 4c 39 f0 <48> 0f 46 e9 49 8d 47 fc 4c 0f 47 e8 4d 0f 46 e7 4c 39 ed 76 a8 e9
RSP: 0018:ffffc9000d6c6f00 EFLAGS: 00000293
RAX: ffffffff816eee50 RBX: ffffc9000d6c6fa8 RCX: ffffffff8e32faf8
RDX: ffffffff8ea3d7a2 RSI: ffffffff8e32faec RDI: ffffffff8138fb37
RBP: ffffffff8e32faec R08: 0000000000000006 R09: 0000000000000013
R10: dffffc0000000000 R11: fffff52001ad8e01 R12: ffffffff8e32faec
R13: ffffffff8e32fb00 R14: ffffffff816eeebf R15: ffffffff8e32faf4
FS:  00007fc75b0116c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc75b032990 CR3: 000000007f85c000 CR4: 00000000003506e0
DR0: 0000200000000300 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <TASK>
 arch_stack_walk+0x10c/0x140 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0xa6/0xf0 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:46 [inline]
 kasan_set_track+0x4b/0x70 mm/kasan/common.c:53
 kasan_save_free_info+0x27/0x40 mm/kasan/generic.c:516
 ____kasan_slab_free+0x126/0x1f0 mm/kasan/common.c:237
 kasan_slab_free include/linux/kasan.h:177 [inline]
 slab_free_hook mm/slub.c:1729 [inline]
 slab_free_freelist_hook+0x133/0x1b0 mm/slub.c:1755
 slab_free mm/slub.c:3687 [inline]
 kmem_cache_free+0xf7/0x2a0 mm/slub.c:3709
 sctp_chunk_destroy net/sctp/sm_make_chunk.c:1504 [inline]
 sctp_chunk_put+0x174/0x200 net/sctp/sm_make_chunk.c:1531
 sctp_datamsg_destroy net/sctp/chunk.c:-1 [inline]
 sctp_datamsg_put+0x3bf/0x500 net/sctp/chunk.c:128
 sctp_chunk_free+0x46/0x60 net/sctp/sm_make_chunk.c:1516
 __sctp_outq_teardown+0x7a4/0x990 net/sctp/outqueue.c:257
 sctp_association_free+0x23c/0x7e0 net/sctp/associola.c:342
 sctp_cmd_delete_tcb net/sctp/sm_sideeffect.c:944 [inline]
 sctp_cmd_interpreter net/sctp/sm_sideeffect.c:1331 [inline]
 sctp_side_effects net/sctp/sm_sideeffect.c:1199 [inline]
 sctp_do_sm+0x373c/0x5610 net/sctp/sm_sideeffect.c:1170
 sctp_primitive_SHUTDOWN+0x94/0xc0 net/sctp/primitive.c:89
 sctp_close+0x3b9/0x890 net/sctp/socket.c:1527
 inet_release+0x139/0x180 net/ipv4/af_inet.c:430
 __sock_release net/socket.c:654 [inline]
 sock_close+0xbf/0x210 net/socket.c:1400
 __fput+0x20a/0x8b0 fs/file_table.c:320
 task_work_run+0x1d0/0x260 kernel/task_work.c:203
 get_signal+0x118d/0x1340 kernel/signal.c:2649
 arch_do_signal_or_restart+0xc4/0x1310 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: 0033:0x7fc75a19de99
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fc75b010fd8 EFLAGS: 00000206 ORIG_RAX: 0000000000000038
RAX: fffffffffffffffc RBX: 00007fc75a426180 RCX: 00007fc75a19de99
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040000000
RBP: 00007fc75a233eaf R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007fc75a426218 R14: 00007fc75a426180 R15: 00007ffc14802188
 </TASK>