INFO: task syz.4.5368:22652 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.5368 state:D stack:25192 pid:22652 ppid:21537 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x15ae/0x4660 kernel/sched/core.c:6700 schedule+0xbd/0x170 kernel/sched/core.c:6774 perf_pending_task_sync kernel/events/core.c:5236 [inline] _free_event+0x176/0xfb0 kernel/events/core.c:5242 put_event kernel/events/core.c:5370 [inline] perf_event_release_kernel+0x7c8/0x850 kernel/events/core.c:5495 perf_release+0x3b/0x40 kernel/events/core.c:5505 __fput+0x221/0x940 fs/file_table.c:418 task_work_run+0x1d4/0x260 kernel/task_work.c:245 exit_task_work include/linux/task_work.h:43 [inline] do_exit+0x986/0x2530 kernel/exit.c:884 do_group_exit+0x22d/0x2f0 kernel/exit.c:1026 __do_sys_exit_group kernel/exit.c:1037 [inline] __se_sys_exit_group kernel/exit.c:1035 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1035 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f09a0f9de59 RSP: 002b:00007f09a1f0ff38 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 00007f09a100a3f8 RCX: 00007f09a0f9de59 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001 RBP: 000000000000000e R08: 0000000000000000 R09: 00007f09a1226038 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 00007f09a1226038 R14: 00007f09a1225fa0 R15: 00007ffc15333078 Showing all locks held in the system: 1 lock held by khungtaskd/29: #0: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #0: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #0: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633 2 locks held by getty/5527: #0: ffff888030f0a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x428/0x1370 drivers/tty/n_tty.c:2217 2 locks held by kworker/1:4/5774: #0: ffff888017c72538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline] #0: ffff888017c72538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2730 #1: ffffc900046dfd00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline] #1: ffffc900046dfd00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2730 2 locks held by syz.1.6129/26194: #0: ffffffff8d187ee8 (event_mutex){+.+.}-{3:3}, at: perf_trace_destroy+0x2e/0x140 kernel/trace/trace_event_perf.c:239 #1: ffffffff8d137778 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:292 [inline] #1: ffffffff8d137778 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x306/0x880 kernel/rcu/tree_exp.h:1004 4 locks held by dhcpcd-run-hook/26207: #0: ffff8880b8f3c298 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x29/0x130 kernel/sched/core.c:559 #1: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #1: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #1: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: do_perf_sw_event kernel/events/core.c:9952 [inline] #1: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: ___perf_sw_event+0x19e/0x730 kernel/events/core.c:9990 #2: ffff88805b844618 (ptlock_ptr(ptdesc)#2){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] #2: ffff88805b844618 (ptlock_ptr(ptdesc)#2){+.+.}-{2:2}, at: __pte_offset_map_lock+0x106/0x1d0 mm/pgtable-generic.c:375 #3: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #3: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #3: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: page_ext_get+0x22/0x2b0 mm/page_ext.c:508 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 29 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Call Trace: dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106 nmi_cpu_backtrace+0x3a6/0x3e0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline] watchdog+0xf59/0xfa0 kernel/hung_task.c:379 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 24191 Comm: kworker/u4:43 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Workqueue: events_unbound nsim_dev_trap_report_work RIP: 0010:in_irqentry_text kernel/stacktrace.c:377 [inline] RIP: 0010:filter_irq_stacks+0x4f/0x90 kernel/stacktrace.c:395 Code: ff 4c 89 f8 48 c1 e8 03 42 80 3c 28 00 74 08 4c 89 ff e8 e4 c5 69 00 49 8b 04 de 48 3d e0 01 a0 8a 0f 93 c1 48 3d f0 15 a0 8a <0f> 92 c2 84 d1 75 27 48 3d b0 a2 95 8a 0f 92 c1 48 3d bb a2 95 8a RSP: 0018:ffffc9000ef3f758 EFLAGS: 00000283 RAX: ffffffff8130f8f8 RBX: 0000000000000009 RCX: 0000000000000000 RDX: 0000000000000001 RSI: 000000000000000b RDI: ffffc9000ef3f7e0 RBP: 0000000000000000 R08: ffff88807b4e1e00 R09: 0000000000000002 R10: 0000000000000001 R11: 0000000000000000 R12: 000000000000000b R13: dffffc0000000000 R14: ffffc9000ef3f7e0 R15: ffffc9000ef3f828 FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fcf72105318 CR3: 000000007b9d9000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: __stack_depot_save+0x1f/0x660 lib/stackdepot.c:377 kasan_save_stack mm/kasan/common.c:47 [inline] kasan_set_track+0x5f/0x70 mm/kasan/common.c:53 kasan_save_free_info+0x28/0x40 mm/kasan/generic.c:522 ____kasan_slab_free+0x126/0x1f0 mm/kasan/common.c:237 kasan_slab_free include/linux/kasan.h:164 [inline] slab_free_hook mm/slub.c:1811 [inline] slab_free_freelist_hook+0x130/0x1a0 mm/slub.c:1837 slab_free mm/slub.c:3830 [inline] kmem_cache_free+0xf8/0x290 mm/slub.c:3852 nsim_dev_trap_report drivers/net/netdevsim/dev.c:821 [inline] nsim_dev_trap_report_work+0x723/0xa90 drivers/net/netdevsim/dev.c:851 process_one_work kernel/workqueue.c:2653 [inline] process_scheduled_works+0xa60/0x1600 kernel/workqueue.c:2730 worker_thread+0xa5e/0xfe0 kernel/workqueue.c:2811 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293