INFO: task syz.7.4133:23228 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.7.4133 state:D stack:25040 pid:23228 ppid: 20653 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11c3/0x4350 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+0x34/0xe30 kernel/events/core.c:5133 put_event kernel/events/core.c:5258 [inline] perf_event_release_kernel+0x7c4/0x850 kernel/events/core.c:5383 perf_release+0x37/0x40 kernel/events/core.c:5393 __fput+0x212/0x8c0 fs/file_table.c:311 task_work_run+0x125/0x1a0 kernel/task_work.c:188 exit_task_work include/linux/task_work.h:33 [inline] do_exit+0x635/0x2110 kernel/exit.c:884 do_group_exit+0x12c/0x2f0 kernel/exit.c:998 get_signal+0x7eb/0x12e0 kernel/signal.c:2901 arch_do_signal_or_restart+0xe6/0x12a0 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: 0033:0x7f5587032e59 RSP: 002b:00007f558528b0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: 0000000000000001 RBX: 00007f55872bafa8 RCX: 00007f5587032e59 RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f55872bafac RBP: 00007f55872bafa0 R08: 00135ea353304ab6 R09: 0000000000000000 R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000 R13: 00007f55872bb038 R14: 00007ffec02b1330 R15: 00007ffec02b1418 Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8c31ef20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 2 locks held by getty/3948: #0: ffff88802c569098 (&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+0x594/0x1a50 drivers/tty/n_tty.c:2158 4 locks held by kworker/u4:8/4894: 3 locks held by kworker/1:11/26424: #0: ffff88802abfad38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1 #1: ffffc9000320fd00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285 #2: ffffffff8d44b148 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xc4/0x1530 net/ipv6/addrconf.c:4113 3 locks held by kworker/0:18/26450: #0: ffff88802abfad38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1 #1: ffffc9000304fd00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285 #2: ffffffff8d44b148 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xc4/0x1530 net/ipv6/addrconf.c:4113 2 locks held by kworker/0:22/26457: #0: ffff888016c72138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1 #1: ffffc9000344fd00 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285 1 lock held by syz-executor/27770: #0: ffffffff8d44b148 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline] #0: ffffffff8d44b148 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7d6/0xf00 net/core/rtnetlink.c:5685 2 locks held by syz.6.5090/28235: 2 locks held by syz.1.5096/28263: #0: ffffffff8d44b148 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:699 [inline] #0: ffffffff8d44b148 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x3d/0x1b0 drivers/net/tun.c:3443 #1: ffffffff8c3239a8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline] #1: ffffffff8c3239a8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x2d1/0x750 kernel/rcu/tree_exp.h:845 2 locks held by syz.4.5097/28267: #0: ffffffff8d43f210 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x324/0x5b0 net/core/net_namespace.c:499 #1: ffffffff8d44b148 (rtnl_mutex){+.+.}-{3:3}, at: wg_netns_pre_exit+0x18/0x1c0 drivers/net/wireguard/device.c:404 ============================================= 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: 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+0xe1b/0xe60 kernel/hung_task.c:369 kthread+0x42e/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 4520 Comm: kworker/1:13 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Workqueue: events nsim_dev_trap_report_work RIP: 0010:lockdep_enabled kernel/locking/lockdep.c:88 [inline] RIP: 0010:lock_release+0xe9/0x8a0 kernel/locking/lockdep.c:5636 Code: c0 84 1e 8b 8d 48 c1 e8 03 42 0f b6 04 28 84 c0 0f 85 5b 05 00 00 83 3d 08 c5 2d 0c 00 0f 84 b9 04 00 00 65 8b 05 b7 1f a5 7e <85> c0 0f 85 aa 04 00 00 65 48 8b 1d 27 16 a5 7e 4c 8d b3 ec 0a 00 RSP: 0018:ffffc900031ef7c0 EFLAGS: 00000002 RAX: 0000000000000000 RBX: 0000000000000001 RCX: 48cc2584f5ce1400 RDX: 0000000000000000 RSI: ffffffff8a7a2a20 RDI: ffffffff8a7a29e0 RBP: ffffc900031ef8d0 R08: ffffffff8d8aeaef R09: 1ffffffff1b15d5d R10: dffffc0000000000 R11: fffffbfff1b15d5e R12: 1ffff9200063df04 R13: dffffc0000000000 R14: 0000000000000200 R15: ffffc900031efa40 FS: 0000000000000000(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005613ec40cbe0 CR3: 0000000065e59000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: crng_make_state+0x38c/0x670 drivers/char/random.c:392 _get_random_bytes+0xfc/0x250 drivers/char/random.c:405 nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:691 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:721 [inline] nsim_dev_trap_report_work+0x646/0xab0 drivers/net/netdevsim/dev.c:762 process_one_work+0x867/0xff0 kernel/workqueue.c:2310 worker_thread+0xad7/0x12a0 kernel/workqueue.c:2457 kthread+0x42e/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287