INFO: task syz.5.2112:13467 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.5.2112 state:D stack:28296 pid:13467 tgid:13465 ppid:7100 task_flags:0x400040 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5360 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6964 __schedule_loop kernel/sched/core.c:7046 [inline] schedule+0x165/0x360 kernel/sched/core.c:7061 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7118 __mutex_lock_common kernel/locking/mutex.c:676 [inline] __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:760 comedi_open+0xc0/0x590 drivers/comedi/comedi_fops.c:2868 chrdev_open+0x4cc/0x5e0 fs/char_dev.c:414 do_dentry_open+0x953/0x13f0 fs/open.c:965 vfs_open+0x3b/0x340 fs/open.c:1095 do_open fs/namei.c:3895 [inline] path_openat+0x2ee5/0x3830 fs/namei.c:4054 do_filp_open+0x1fa/0x410 fs/namei.c:4081 do_sys_openat2+0x121/0x1c0 fs/open.c:1435 do_sys_open fs/open.c:1450 [inline] __do_sys_openat fs/open.c:1466 [inline] __se_sys_openat fs/open.c:1461 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1461 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f4b5698eba9 RSP: 002b:00007f4b5785c038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f4b56bd5fa0 RCX: 00007f4b5698eba9 RDX: 0000000000028444 RSI: 0000200000000040 RDI: 00000000ffffff9c RBP: 00007f4b56a11e19 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f4b56bd6038 R14: 00007f4b56bd5fa0 R15: 00007ffe6c885d68 Showing all locks held in the system: 3 locks held by kworker/1:0/24: #0: ffff88813ff41548 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff88813ff41548 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc900001e7ba0 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc900001e7ba0 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffff88804f8db240 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x1f7/0x3b0 drivers/net/netdevsim/fib.c:1490 1 lock held by khungtaskd/31: #0: ffffffff8e33d660 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e33d660 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e33d660 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by getty/5625: #0: ffff8880332ef0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900036bb2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 3 locks held by kworker/0:9/8343: 2 locks held by kworker/u8:14/12708: 1 lock held by syz.2.2028/13176: 1 lock held by syz.5.2112/13467: #0: ffff88814cb208f8 (&dev->mutex#4){+.+.}-{4:4}, at: comedi_open+0xc0/0x590 drivers/comedi/comedi_fops.c:2868 1 lock held by syz.8.2565/15017: #0: ffff88814cb208f8 (&dev->mutex#4){+.+.}-{4:4}, at: comedi_open+0xc0/0x590 drivers/comedi/comedi_fops.c:2868 3 locks held by syz-executor/15220: #0: ffffffff8f745308 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8f745308 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #0: ffffffff8f745308 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8db/0x1c70 net/core/rtnetlink.c:4056 #1: ffff8880490cd4e8 (&wg->device_update_lock){+.+.}-{4:4}, at: wg_open+0x227/0x420 drivers/net/wireguard/device.c:50 #2: ffffffff8e3430f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline] #2: ffffffff8e3430f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730 kernel/rcu/tree_exp.h:957 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:332 [inline] watchdog+0xf60/0xfa0 kernel/hung_task.c:495 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 12706 Comm: kworker/u8:13 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Workqueue: bat_events batadv_iv_send_outstanding_bat_ogm_packet RIP: 0010:__raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] RIP: 0010:_raw_spin_lock_bh+0x31/0x50 kernel/locking/spinlock.c:178 Code: 48 89 fb 4c 8b 74 24 10 4c 89 f7 be 01 02 00 00 e8 94 9f fe f5 48 8d 7b 18 31 f6 31 d2 31 c9 41 b8 01 00 00 00 45 31 c9 41 56 0a 2b 17 f6 48 83 c4 08 48 89 df 5b 41 5e e9 5b cf 17 f6 66 66 RSP: 0018:ffffc9000e1ff680 EFLAGS: 00000246 RAX: a626e5acd4523100 RBX: ffff888033cf3f40 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff888033cf3f58 RBP: 00000000000000fd R08: 0000000000000001 R09: 0000000000000000 R10: dffffc0000000000 R11: fffffbfff1f88787 R12: ffff888030a351d0 R13: ffff888030a351c8 R14: ffffffff8b542928 R15: ffff888030a351c0 FS: 0000000000000000(0000) GS:ffff8881259e1000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c3deec2 CR3: 0000000077920000 CR4: 00000000003526f0 Call Trace: spin_lock_bh include/linux/spinlock.h:356 [inline] batadv_tt_local_purge_pending_clients+0xf8/0x380 net/batman-adv/translation-table.c:3603 batadv_tt_local_commit_changes_nolock+0x59c/0xd90 net/batman-adv/translation-table.c:3645 batadv_tt_local_commit_changes+0x26/0x40 net/batman-adv/translation-table.c:3667 batadv_iv_ogm_schedule_buff net/batman-adv/bat_iv_ogm.c:820 [inline] batadv_iv_ogm_schedule+0x276/0xf00 net/batman-adv/bat_iv_ogm.c:874 batadv_iv_send_outstanding_bat_ogm_packet+0x6c6/0x7e0 net/batman-adv/bat_iv_ogm.c:1714 process_one_work kernel/workqueue.c:3263 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245