INFO: task syz.0.17:4460 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.17 state:D stack:29184 pid:4460 ppid:4384 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561 schedule+0xb9/0x180 kernel/sched/core.c:6637 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6696 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0x555/0xaf0 kernel/locking/mutex.c:747 __fdget_pos+0x2ae/0x360 fs/file.c:1038 fdget_pos include/linux/file.h:74 [inline] __do_sys_getdents64 fs/readdir.c:365 [inline] __se_sys_getdents64+0xbe/0x260 fs/readdir.c:354 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f2328b8eec9 RSP: 002b:00007f23281fe038 EFLAGS: 00000246 ORIG_RAX: 00000000000000d9 RAX: ffffffffffffffda RBX: 00007f2328de6090 RCX: 00007f2328b8eec9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000006 RBP: 00007f2328c11f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f2328de6128 R14: 00007f2328de6090 R15: 00007ffc5a1db028 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8cb2b570 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517 1 lock held by rcu_tasks_trace/13: #0: ffffffff8cb2bd90 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517 1 lock held by khungtaskd/28: #0: ffffffff8cb2abe0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #0: ffffffff8cb2abe0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #0: ffffffff8cb2abe0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513 2 locks held by getty/4028: #0: ffff8880300fd098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244 #1: ffffc9000327e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x41b/0x1380 drivers/tty/n_tty.c:2198 2 locks held by syz.0.17/4459: #0: ffff88802f204868 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038 #1: ffff88805b458150 (&sb->s_type->i_mutex_key#21){.+.+}-{3:3}, at: iterate_dir+0x10d/0x560 fs/readdir.c:55 1 lock held by syz.0.17/4460: #0: ffff88802f204868 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038 2 locks held by kworker/u4:6/4461: 2 locks held by syz.1.18/4483: #0: ffff88807d48a0e8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038 #1: ffff88805b560150 (&sb->s_type->i_mutex_key#21){.+.+}-{3:3}, at: iterate_dir+0x10d/0x560 fs/readdir.c:55 1 lock held by syz.1.18/4484: #0: ffff88807d48a0e8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038 2 locks held by syz.2.19/4512: #0: ffff888078368d68 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038 #1: ffff88805b560728 (&sb->s_type->i_mutex_key#21){.+.+}-{3:3}, at: iterate_dir+0x10d/0x560 fs/readdir.c:55 1 lock held by syz.2.19/4513: #0: ffff888078368d68 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038 2 locks held by syz.3.20/4535: #0: ffff8880281da0e8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038 #1: ffff88805b560d00 (&sb->s_type->i_mutex_key#21){.+.+}-{3:3}, at: iterate_dir+0x10d/0x560 fs/readdir.c:55 1 lock held by syz.3.20/4536: #0: ffff8880281da0e8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038 2 locks held by syz.4.21/4564: #0: ffff88807d38eae8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038 #1: ffff88805b458728 (&sb->s_type->i_mutex_key#21){.+.+}-{3:3}, at: iterate_dir+0x10d/0x560 fs/readdir.c:55 1 lock held by syz.4.21/4565: #0: ffff88807d38eae8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038 2 locks held by syz.5.22/4593: #0: ffff88807c12aae8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038 #1: ffff88805b5612d8 (&sb->s_type->i_mutex_key#21){.+.+}-{3:3}, at: iterate_dir+0x10d/0x560 fs/readdir.c:55 1 lock held by syz.5.22/4594: #0: ffff88807c12aae8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038 2 locks held by syz.6.23/4627: #0: ffff88807baf9268 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038 #1: ffff88805b5618b0 (&sb->s_type->i_mutex_key#21){.+.+}-{3:3}, at: iterate_dir+0x10d/0x560 fs/readdir.c:55 1 lock held by syz.6.23/4628: #0: ffff88807baf9268 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038 2 locks held by syz.7.24/4655: #0: ffff88807c589768 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038 #1: ffff88805b561e88 (&sb->s_type->i_mutex_key#21){.+.+}-{3:3}, at: iterate_dir+0x10d/0x560 fs/readdir.c:55 1 lock held by syz.7.24/4657: #0: ffff88807c589768 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038 2 locks held by syz.8.25/4684: #0: ffff8880789514e8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038 #1: ffff88805b562460 (&sb->s_type->i_mutex_key#21){.+.+}-{3:3}, at: iterate_dir+0x10d/0x560 fs/readdir.c:55 1 lock held by syz.8.25/4686: #0: ffff8880789514e8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 28 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+0x168/0x22e lib/dump_stack.c:106 nmi_cpu_backtrace+0x3f4/0x470 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x1d4/0x450 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline] watchdog+0xeee/0xf30 kernel/hung_task.c:377 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 4461 Comm: kworker/u4:6 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Workqueue: events_unbound nsim_dev_trap_report_work RIP: 0010:check_preemption_disabled+0x1/0x110 lib/smp_processor_id.c:13 Code: 20 74 bc 8c 4c 89 f6 e8 fd 1c 17 fa e9 6e ff ff ff 00 00 cc cc 00 00 cc cc 48 c7 c7 80 fc de 8a 48 c7 c6 c0 fc de 8a eb 00 55 <41> 57 41 56 53 48 83 ec 10 65 48 8b 04 25 28 00 00 00 48 89 44 24 RSP: 0018:ffffc900035577f8 EFLAGS: 00000046 RAX: 0000000080000001 RBX: ffffffff847a3d39 RCX: ffff88807b035940 RDX: 0000000000000000 RSI: ffffffff8a8c0520 RDI: ffffffff8adefce0 RBP: ffffc900035579f0 R08: dffffc0000000000 R09: ffffc90003557a80 R10: fffff520006aaf58 R11: 1ffff920006aaf50 R12: ffffc90003557900 R13: 0000000000000002 R14: 0000000000000200 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055ef72df2a38 CR3: 000000000c88e000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lockdep_hardirqs_off+0xa7/0x100 kernel/locking/lockdep.c:4400 trace_hardirqs_off+0xe/0x40 kernel/trace/trace_preemptirq.c:76 crng_make_state+0x159/0xa90 drivers/char/random.c:328 _get_random_bytes+0xd2/0x210 drivers/char/random.c:366 nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:776 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:805 [inline] nsim_dev_trap_report_work+0x650/0xaf0 drivers/net/netdevsim/dev.c:851 process_one_work+0x898/0x1160 kernel/workqueue.c:2292 worker_thread+0xaa2/0x1250 kernel/workqueue.c:2439 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295