INFO: task syz.2.19:6476 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.19 state:D stack:28296 pid:6476 tgid:6475 ppid:6318 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+0x950/0x13f0 fs/open.c:965 vfs_open+0x3b/0x340 fs/open.c:1095 do_open fs/namei.c:3887 [inline] path_openat+0x2ee5/0x3830 fs/namei.c:4046 do_filp_open+0x1fa/0x410 fs/namei.c:4073 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: 0033:0x7f7085b8eb69 RSP: 002b:00007f7086917038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f7085db5fa0 RCX: 00007f7085b8eb69 RDX: 0000000000000400 RSI: 0000200000000080 RDI: ffffffffffffff9c RBP: 00007f7085c11df1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007f7085db5fa0 R15: 00007ffdc1e7e248 Showing all locks held in the system: 3 locks held by kworker/u8:1/13: #0: ffff8880b8639f98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:636 #1: ffffc90000127ba0 ((work_completion)(&(&bat_priv->nc.work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc90000127ba0 ((work_completion)(&(&bat_priv->nc.work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffffffff8e53cf20 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #2: ffffffff8e53cf20 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #2: ffffffff8e53cf20 (rcu_read_lock){....}-{1:3}, at: batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline] #2: ffffffff8e53cf20 (rcu_read_lock){....}-{1:3}, at: batadv_nc_worker+0xd2/0x610 net/batman-adv/network-coding.c:719 1 lock held by khungtaskd/31: #0: ffffffff8e53cf20 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e53cf20 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e53cf20 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by getty/5619: #0: ffff888033f9e0a0 (&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 2 locks held by syz.3.20/6472: 1 lock held by syz.2.19/6476: #0: ffff88814c8fc8f8 (&dev->mutex#4){+.+.}-{4:4}, at: comedi_open+0xc0/0x590 drivers/comedi/comedi_fops.c:2868 1 lock held by syz.0.17/6492: #0: ffff88814c8fc8f8 (&dev->mutex#4){+.+.}-{4:4}, at: comedi_open+0xc0/0x590 drivers/comedi/comedi_fops.c:2868 1 lock held by syz.1.18/6495: #0: ffff88814c8fc8f8 (&dev->mutex#4){+.+.}-{4:4}, at: comedi_open+0xc0/0x590 drivers/comedi/comedi_fops.c:2868 1 lock held by syz.5.22/6695: #0: ffff88814c8fc8f8 (&dev->mutex#4){+.+.}-{4:4}, at: comedi_open+0xc0/0x590 drivers/comedi/comedi_fops.c:2868 1 lock held by syz.4.21/6698: #0: ffff88814c8fc8f8 (&dev->mutex#4){+.+.}-{4:4}, at: comedi_open+0xc0/0x590 drivers/comedi/comedi_fops.c:2868 1 lock held by syz.6.23/6701: #0: ffff88814c8fc8f8 (&dev->mutex#4){+.+.}-{4:4}, at: comedi_open+0xc0/0x590 drivers/comedi/comedi_fops.c:2868 1 lock held by syz.7.24/6704: #0: ffff88814c8fc8f8 (&dev->mutex#4){+.+.}-{4:4}, at: comedi_open+0xc0/0x590 drivers/comedi/comedi_fops.c:2868 1 lock held by syz.8.25/6786: #0: ffff88814c8fc8f8 (&dev->mutex#4){+.+.}-{4:4}, at: comedi_open+0xc0/0x590 drivers/comedi/comedi_fops.c:2868 1 lock held by syz.9.26/6809: #0: ffff88814c8fc8f8 (&dev->mutex#4){+.+.}-{4:4}, at: comedi_open+0xc0/0x590 drivers/comedi/comedi_fops.c:2868 1 lock held by syz.2.27/6812: #0: ffff88814c8fc8f8 (&dev->mutex#4){+.+.}-{4:4}, at: comedi_open+0xc0/0x590 drivers/comedi/comedi_fops.c:2868 1 lock held by syz.3.28/6815: #0: ffff88814c8fc8f8 (&dev->mutex#4){+.+.}-{4:4}, at: comedi_open+0xc0/0x590 drivers/comedi/comedi_fops.c:2868 1 lock held by syz.0.29/6879: #0: ffff88814c8fc8f8 (&dev->mutex#4){+.+.}-{4:4}, at: comedi_open+0xc0/0x590 drivers/comedi/comedi_fops.c:2868 1 lock held by syz.1.30/6904: #0: ffff88814c8fc8f8 (&dev->mutex#4){+.+.}-{4:4}, at: comedi_open+0xc0/0x590 drivers/comedi/comedi_fops.c:2868 1 lock held by syz.5.31/6915: #0: ffff88814c8fc8f8 (&dev->mutex#4){+.+.}-{4:4}, at: comedi_open+0xc0/0x590 drivers/comedi/comedi_fops.c:2868 1 lock held by syz.6.32/6919: #0: ffff88814c8fc8f8 (&dev->mutex#4){+.+.}-{4:4}, at: comedi_open+0xc0/0x590 drivers/comedi/comedi_fops.c:2868 1 lock held by syz.7.33/6984: #0: ffff88814c8fc8f8 (&dev->mutex#4){+.+.}-{4:4}, at: comedi_open+0xc0/0x590 drivers/comedi/comedi_fops.c:2868 1 lock held by syz.4.34/7024: #0: ffff88814c8fc8f8 (&dev->mutex#4){+.+.}-{4:4}, at: comedi_open+0xc0/0x590 drivers/comedi/comedi_fops.c:2868 1 lock held by syz.9.36/7039: #0: ffff88814c8fc8f8 (&dev->mutex#4){+.+.}-{4:4}, at: comedi_open+0xc0/0x590 drivers/comedi/comedi_fops.c:2868 1 lock held by syz.8.35/7041: #0: ffff88814c8fc8f8 (&dev->mutex#4){+.+.}-{4:4}, at: comedi_open+0xc0/0x590 drivers/comedi/comedi_fops.c:2868 1 lock held by syz.2.37/7083: #0: ffff88814c8fc8f8 (&dev->mutex#4){+.+.}-{4:4}, at: comedi_open+0xc0/0x590 drivers/comedi/comedi_fops.c:2868 1 lock held by syz.3.38/7122: #0: ffff88814c8fc8f8 (&dev->mutex#4){+.+.}-{4:4}, at: comedi_open+0xc0/0x590 drivers/comedi/comedi_fops.c:2868 1 lock held by syz.0.39/7129: #0: ffff88814c8fc8f8 (&dev->mutex#4){+.+.}-{4:4}, at: comedi_open+0xc0/0x590 drivers/comedi/comedi_fops.c:2868 1 lock held by syz.1.40/7132: #0: ffff88814c8fc8f8 (&dev->mutex#4){+.+.}-{4:4}, at: comedi_open+0xc0/0x590 drivers/comedi/comedi_fops.c:2868 1 lock held by syz.5.41/7164: #0: ffff88814c8fc8f8 (&dev->mutex#4){+.+.}-{4:4}, at: comedi_open+0xc0/0x590 drivers/comedi/comedi_fops.c:2868 3 locks held by syz-executor/7167: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 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+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x47c/0x820 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 6203 Comm: syz-execprog Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:load_new_mm_cr3+0x14f/0x1e0 arch/x86/mm/tlb.c:582 Code: b7 c3 3d ff 07 00 00 73 4c f7 c3 00 08 00 00 75 50 ff c3 0f b7 c3 48 09 c1 48 b8 00 00 00 00 00 00 00 80 48 09 c8 0f 22 d8 5b <41> 5c 41 5e 41 5f c3 cc cc cc cc cc 90 0f 0b 90 eb af 90 0f 0b 90 RSP: 0018:ffffc900030078a0 EFLAGS: 00000046 RAX: 000000005a40e000 RBX: dffffc0000000000 RCX: ffff88801ebe3c80 RDX: 0000000040000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc90003007990 R08: ffff88807de8b25f R09: 1ffff1100fbd164b R10: dffffc0000000000 R11: ffffed100fbd164c R12: ffff88807de8abb8 R13: ffff88807de8ab00 R14: ffff88805a40e000 R15: 0000000000010000 FS: 000000c00007e098(0000) GS:ffff8881258ba000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f8b261efbf0 CR3: 000000005a40e000 CR4: 00000000003526f0 Call Trace: switch_mm_irqs_off+0x52d/0x7a0 arch/x86/mm/tlb.c:930 context_switch kernel/sched/core.c:5344 [inline] __schedule+0x110e/0x4cc0 kernel/sched/core.c:6964 __schedule_loop kernel/sched/core.c:7046 [inline] schedule+0x165/0x360 kernel/sched/core.c:7061 do_nanosleep+0x1c7/0x600 kernel/time/hrtimer.c:2100 hrtimer_nanosleep+0x169/0x360 kernel/time/hrtimer.c:2147 __do_sys_nanosleep kernel/time/hrtimer.c:2182 [inline] __se_sys_nanosleep kernel/time/hrtimer.c:2168 [inline] __x64_sys_nanosleep+0x231/0x290 kernel/time/hrtimer.c:2168 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: 0033:0x47fad7 Code: Unable to access opcode bytes at 0x47faad. RSP: 002b:000000c00005ff18 EFLAGS: 00000202 ORIG_RAX: 0000000000000023 RAX: ffffffffffffffda RBX: 0000000000000014 RCX: 000000000047fad7 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000c00005ff18 RBP: 000000c00005ff28 R08: 000000003b64f410 R09: 7fffffffffffffff R10: 3fffffffffffffff R11: 0000000000000202 R12: 000000c00005ff18 R13: 000000c00007e008 R14: 000000c000002700 R15: 000000c000002700