INFO: task syz.8.1542:13230 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.8.1542 state:D stack:24360 pid:13230 ppid:6304 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x1553/0x45a0 kernel/sched/core.c:6700 schedule+0xbd/0x170 kernel/sched/core.c:6774 perf_pending_task_sync kernel/events/core.c:5242 [inline] _free_event+0x174/0xf30 kernel/events/core.c:5248 put_event kernel/events/core.c:5376 [inline] perf_event_release_kernel+0x842/0x8d0 kernel/events/core.c:5501 perf_release+0x3b/0x40 kernel/events/core.c:5511 __fput+0x234/0x970 fs/file_table.c:384 task_work_run+0x1d4/0x260 kernel/task_work.c:245 exit_task_work include/linux/task_work.h:43 [inline] do_exit+0x95a/0x2460 kernel/exit.c:883 do_group_exit+0x21b/0x2d0 kernel/exit.c:1024 get_signal+0x12fc/0x13f0 kernel/signal.c:2902 arch_do_signal_or_restart+0xc2/0x800 arch/x86/kernel/signal.c:310 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:291 [inline] syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302 do_syscall_64+0x61/0xa0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f557839bf79 RSP: 002b:00007f55791e40e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007f5578615fa8 RCX: 00007f557839bf79 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f5578615fa8 RBP: 00007f5578615fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f5578616038 R14: 00007fffacef1630 R15: 00007fffacef1718 Showing all locks held in the system: 1 lock held by khungtaskd/29: #0: ffffffff8d131fa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #0: ffffffff8d131fa0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #0: ffffffff8d131fa0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633 2 locks held by getty/5527: #0: ffff88814c97c0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000328b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x433/0x1390 drivers/tty/n_tty.c:2217 3 locks held by kworker/0:3/5811: #0: ffff888017c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #0: ffff888017c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2711 #1: ffffc900048d7d00 (set_printk_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #1: ffffc900048d7d00 (set_printk_work){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2711 #2: ffffffff8d187f28 (event_mutex){+.+.}-{3:3}, at: __ftrace_set_clr_event kernel/trace/trace_events.c:1230 [inline] #2: ffffffff8d187f28 (event_mutex){+.+.}-{3:3}, at: trace_set_clr_event+0xc2/0x130 kernel/trace/trace_events.c:1296 2 locks held by kworker/1:4/5834: #0: ffff888017c72538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #0: ffff888017c72538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2711 #1: ffffc90004a27d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #1: ffffc90004a27d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2711 3 locks held by kworker/0:8/8134: #0: ffff8880b8e3c018 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:559 #1: ffffffff8d131fa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #1: ffffffff8d131fa0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #1: ffffffff8d131fa0 (rcu_read_lock){....}-{1:2}, at: do_perf_sw_event kernel/events/core.c:9928 [inline] #1: ffffffff8d131fa0 (rcu_read_lock){....}-{1:2}, at: ___perf_sw_event+0x199/0x730 kernel/events/core.c:9966 #2: ffff88802e8e8ee0 (&r->consumer_lock#2){+.+.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] #2: ffff88802e8e8ee0 (&r->consumer_lock#2){+.+.}-{2:2}, at: ptr_ring_consume_bh include/linux/ptr_ring.h:365 [inline] #2: ffff88802e8e8ee0 (&r->consumer_lock#2){+.+.}-{2:2}, at: wg_packet_decrypt_worker+0x977/0xdf0 drivers/net/wireguard/receive.c:499 2 locks held by kworker/u4:19/13307: #0: ffff888017c71538 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #0: ffff888017c71538 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2711 #1: ffffc9000b95fd00 ((work_completion)(&map->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #1: ffffc9000b95fd00 ((work_completion)(&map->work)){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2711 2 locks held by kworker/u4:20/13308: #0: ffff8880b8e3c018 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:559 #1: ffffc9000b96fd00 ((work_completion)(&(&bat_priv->nc.work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #1: ffffc9000b96fd00 ((work_completion)(&(&bat_priv->nc.work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2711 2 locks held by kworker/u4:22/13310: #0: ffff888017c71538 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #0: ffff888017c71538 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2711 #1: ffffc9000b9bfd00 ((work_completion)(&map->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #1: ffffc9000b9bfd00 ((work_completion)(&map->work)){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2711 3 locks held by kworker/u4:28/13318: #0: ffff888017c71538 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #0: ffff888017c71538 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2711 #1: ffffc9000bb9fd00 ((work_completion)(&map->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #1: ffffc9000bb9fd00 ((work_completion)(&map->work)){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2711 #2: ffffffff8d137978 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:324 [inline] #2: ffffffff8d137978 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3da/0x880 kernel/rcu/tree_exp.h:1004 1 lock held by syz.7.2060/15806: #0: ffffffff8e3c0208 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:698 [inline] #0: ffffffff8e3c0208 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x41/0x1c0 drivers/net/tun.c:3511 1 lock held by syz.2.2061/15808: #0: ffffffff8d187f28 (event_mutex){+.+.}-{3:3}, at: perf_trace_destroy+0x2e/0x140 kernel/trace/trace_event_perf.c:239 1 lock held by dhcpcd/15818: #0: ffff88806ba04130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1780 [inline] #0: ffff88806ba04130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x32/0xcc0 net/packet/af_packet.c:3258 1 lock held by syz.5.2065/15820: #0: ffff88805e492c20 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline] #0: ffff88805e492c20 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: __sock_release net/socket.c:658 [inline] #0: ffff88805e492c20 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: sock_close+0x9b/0x230 net/socket.c:1420 1 lock held by syz.5.2065/15821: #0: ffff888019aae130 (sk_lock-AF_CAN){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1780 [inline] #0: ffff888019aae130 (sk_lock-AF_CAN){+.+.}-{0:0}, at: bcm_release+0x1cd/0x860 net/can/bcm.c:1562 6 locks held by syz.5.2065/15824: #0: ffff88802e0474c8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2a3/0x330 fs/file.c:1040 #1: ffff88802f9fe418 (sb_writers#11){.+.+}-{0:0}, at: vfs_write+0x21b/0x990 fs/read_write.c:580 #2: ffff888026702488 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e7/0x520 fs/kernfs/file.c:343 #3: ffffffff8d15ba08 (cgroup_mutex){+.+.}-{3:3}, at: cgroup_lock include/linux/cgroup.h:369 [inline] #3: ffffffff8d15ba08 (cgroup_mutex){+.+.}-{3:3}, at: cgroup_kn_lock_live+0xf2/0x230 kernel/cgroup/cgroup.c:1677 #4: ffffffff8cfcd210 (cpu_hotplug_lock){++++}-{0:0}, at: cgroup_attach_lock kernel/cgroup/cgroup.c:2414 [inline] #4: ffffffff8cfcd210 (cpu_hotplug_lock){++++}-{0:0}, at: cgroup_procs_write_start+0x18a/0x610 kernel/cgroup/cgroup.c:2918 #5: ffffffff8d15bbf0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: cgroup_attach_lock kernel/cgroup/cgroup.c:2416 [inline] #5: ffffffff8d15bbf0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: cgroup_procs_write_start+0x1a0/0x610 kernel/cgroup/cgroup.c:2918 2 locks held by syz.9.2066/15823: #0: ffffffff97315c30 (&pmus_srcu){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:116 [inline] #0: ffffffff97315c30 (&pmus_srcu){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:215 [inline] #0: ffffffff97315c30 (&pmus_srcu){.+.+}-{0:0}, at: perf_init_event kernel/events/core.c:11848 [inline] #0: ffffffff97315c30 (&pmus_srcu){.+.+}-{0:0}, at: perf_event_alloc+0xc06/0x21b0 kernel/events/core.c:12169 #1: ffffffff8d187f28 (event_mutex){+.+.}-{3:3}, at: perf_trace_init+0x50/0x2d0 kernel/trace/trace_event_perf.c:221 2 locks held by syz.9.2066/15825: #0: ffffffff97315c30 (&pmus_srcu){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:116 [inline] #0: ffffffff97315c30 (&pmus_srcu){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:215 [inline] #0: ffffffff97315c30 (&pmus_srcu){.+.+}-{0:0}, at: perf_init_event kernel/events/core.c:11848 [inline] #0: ffffffff97315c30 (&pmus_srcu){.+.+}-{0:0}, at: perf_event_alloc+0xc06/0x21b0 kernel/events/core.c:12169 #1: ffffffff8d187f28 (event_mutex){+.+.}-{3:3}, at: perf_trace_init+0x50/0x2d0 kernel/trace/trace_event_perf.c:221 1 lock held by dhcpcd/15832: #0: ffff88802eaf8130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1780 [inline] #0: ffff88802eaf8130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x32/0xcc0 net/packet/af_packet.c:3258 1 lock held by dhcpcd/15833: #0: ffff88806744e130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1780 [inline] #0: ffff88806744e130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x32/0xcc0 net/packet/af_packet.c:3258 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 29 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 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+0xf3d/0xf80 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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 13310 Comm: kworker/u4:22 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Workqueue: events_unbound nsim_dev_trap_report_work RIP: 0010:__sanitizer_cov_trace_switch+0x81/0x120 kernel/kcov.c:349 Code: 00 00 00 b9 01 00 00 00 48 85 c0 0f 84 ae 00 00 00 41 57 41 56 41 54 53 48 8b 54 24 20 65 4c 8b 05 e4 9c 7c 7e 45 31 c9 eb 08 <49> ff c1 4c 39 c8 74 77 4e 8b 54 ce 10 65 44 8b 1d d2 9c 7c 7e 41 RSP: 0018:ffffc9000b9bf530 EFLAGS: 00000293 RAX: 0000000000000008 RBX: 0000000000000000 RCX: 0000000000000003 RDX: ffffffff813b3d62 RSI: ffffffff8cfa0760 RDI: 0000000000000005 RBP: ffffc9000b9bf678 R08: ffff888021f8bc00 R09: 0000000000000001 R10: 0000000000000003 R11: 0000000000000000 R12: ffffc9000b9bf628 R13: dffffc0000000000 R14: 0000000000000005 R15: ffffffff8f19768a FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fa4c909aff0 CR3: 00000000796ec000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000200000000300 DR3: 0000200000000300 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: unwind_next_frame+0x742/0x2970 arch/x86/kernel/unwind_orc.c:515 arch_stack_walk+0x144/0x190 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xaa/0x100 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4e/0x70 mm/kasan/common.c:53 __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:188 [inline] slab_post_alloc_hook+0x6e/0x4b0 mm/slab.h:767 slab_alloc_node mm/slub.c:3495 [inline] kmem_cache_alloc_node+0x14c/0x320 mm/slub.c:3540 __alloc_skb+0x103/0x2c0 net/core/skbuff.c:643 alloc_skb include/linux/skbuff.h:1284 [inline] nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:748 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:805 [inline] nsim_dev_trap_report_work+0x293/0xb00 drivers/net/netdevsim/dev.c:851 process_one_work kernel/workqueue.c:2634 [inline] process_scheduled_works+0xa5d/0x15d0 kernel/workqueue.c:2711 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792 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