INFO: task syz.1.132:6395 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.132 state:D stack:22696 pid:6395 ppid:5794 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5380 [inline] __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699 schedule+0xbd/0x170 kernel/sched/core.c:6773 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+0x836/0x8c0 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+0x1ce/0x250 kernel/task_work.c:239 get_signal+0x1235/0x1400 kernel/signal.c:2678 arch_do_signal_or_restart+0x96/0x780 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xf6/0x180 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+0x61/0xb0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7ff6edf8eec9 RSP: 002b:00007ff6eed9bfe8 EFLAGS: 00000206 ORIG_RAX: 0000000000000038 RAX: fffffffffffffffc RBX: 00007ff6ee1e6090 RCX: 00007ff6edf8eec9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000630c1000 RBP: 00007ff6ee011f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 00007ff6ee1e6128 R14: 00007ff6ee1e6090 R15: 00007ffdd0939668 Showing all locks held in the system: 1 lock held by khungtaskd/29: #0: ffffffff8cd2fe20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #0: ffffffff8cd2fe20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #0: ffffffff8cd2fe20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633 2 locks held by getty/5549: #0: ffff88802ccc60a0 (&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+0x425/0x1380 drivers/tty/n_tty.c:2217 3 locks held by kworker/1:6/7582: 3 locks held by kworker/u4:9/7819: #0: ffff88802bfd2938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #0: ffff88802bfd2938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #1: ffffc9000c877d00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #1: ffffc9000c877d00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #2: ffffffff8dfbc3c8 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xd0/0x14e0 net/ipv6/addrconf.c:4158 2 locks held by syz.6.551/8527: #0: ffffffff8dfbc3c8 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:698 [inline] #0: ffffffff8dfbc3c8 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x41/0x1c0 drivers/net/tun.c:3511 #1: ffffffff8cd357f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:292 [inline] #1: ffffffff8cd357f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x448/0x830 kernel/rcu/tree_exp.h:1004 1 lock held by syz.0.554/8519: #0: ffffffff8dfbc3c8 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:698 [inline] #0: ffffffff8dfbc3c8 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x41/0x1c0 drivers/net/tun.c:3511 1 lock held by syz.0.554/8521: #0: ffffffff8dfbc3c8 (rtnl_mutex){+.+.}-{3:3}, at: __tun_chr_ioctl+0x3b9/0x1fd0 drivers/net/tun.c:3121 1 lock held by syz.7.555/8528: #0: ffffffff8dfbc3c8 (rtnl_mutex){+.+.}-{3:3}, at: __tun_chr_ioctl+0x3b9/0x1fd0 drivers/net/tun.c:3121 1 lock held by syz.7.555/8529: #0: ffffffff8dfbc3c8 (rtnl_mutex){+.+.}-{3:3}, at: tun_set_queue drivers/net/tun.c:2992 [inline] #0: ffffffff8dfbc3c8 (rtnl_mutex){+.+.}-{3:3}, at: __tun_chr_ioctl+0x36a/0x1fd0 drivers/net/tun.c:3114 ============================================= 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 08/18/2025 Call Trace: dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106 nmi_cpu_backtrace+0x39b/0x3d0 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+0xf41/0xf80 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 5878 Comm: kworker/1:5 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Workqueue: events_power_efficient gc_worker RIP: 0010:gc_worker+0x3a3/0x14b0 net/netfilter/nf_conntrack_core.c:1510 Code: f8 3b 5c 24 3c 0f 83 ba 0a 00 00 89 d8 4d 8d 34 c6 4c 89 f0 48 c1 e8 03 42 80 3c 28 00 74 08 4c 89 f7 e8 50 7b 30 f9 4d 8b 3e <4c> 89 fe 48 83 e6 01 31 ff e8 5f 34 d9 f8 4c 89 f8 48 83 e0 01 0f RSP: 0018:ffffc90004adfa60 EFLAGS: 00000246 RAX: 1ffff11005823d70 RBX: 0000000000023d70 RCX: 0000000000000000 RDX: ffff88801eed8000 RSI: 0000000000040000 RDI: 0000000000023d70 RBP: ffffc90004adfbb0 R08: ffffffff90da7597 R09: 1ffffffff21b4eb2 R10: dffffc0000000000 R11: fffffbfff21b4eb3 R12: ffff88801eed8000 R13: dffffc0000000000 R14: ffff88802c11eb80 R15: 0000000000047ae1 FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f51d07b4198 CR3: 0000000066296000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: process_one_work kernel/workqueue.c:2634 [inline] process_scheduled_works+0xa45/0x15b0 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