INFO: task syz.0.16:5074 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.16 state:D stack:29088 pid: 5074 ppid: 4787 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11bb/0x4390 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6537 __mutex_lock_common+0xc71/0x2390 kernel/locking/mutex.c:669 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743 __fdget_pos+0x2bf/0x370 fs/file.c:1056 fdget_pos include/linux/file.h:76 [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:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f55de1ca969 RSP: 002b:00007f55dd419038 EFLAGS: 00000246 ORIG_RAX: 00000000000000d9 RAX: ffffffffffffffda RBX: 00007f55de3f2080 RCX: 00007f55de1ca969 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000006 RBP: 00007f55de24cab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007f55de3f2080 R15: 00007ffdc38d2ad8 Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8c11c720 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 2 locks held by kworker/u4:3/155: 2 locks held by getty/3947: #0: ffff88802c1dd098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252 #1: ffffc900025e62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5ba/0x1a30 drivers/tty/n_tty.c:2158 3 locks held by kworker/0:21/4662: #0: ffff888016870938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1 #1: ffffc9000305fd00 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285 #2: ffff88805d4da240 (&data->fib_lock){+.+.}-{3:3}, at: nsim_fib_event_work+0x271/0x3240 drivers/net/netdevsim/fib.c:1480 2 locks held by syz.0.16/5073: #0: ffff8880295dd770 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2bf/0x370 fs/file.c:1056 #1: ffff88806ef78298 (&sb->s_type->i_mutex_key#21){.+.+}-{3:3}, at: iterate_dir+0x10d/0x560 fs/readdir.c:55 1 lock held by syz.0.16/5074: #0: ffff8880295dd770 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2bf/0x370 fs/file.c:1056 2 locks held by syz.1.17/5095: #0: ffff88802b299270 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2bf/0x370 fs/file.c:1056 #1: ffff88806ef788f0 (&sb->s_type->i_mutex_key#21){.+.+}-{3:3}, at: iterate_dir+0x10d/0x560 fs/readdir.c:55 1 lock held by syz.1.17/5097: #0: ffff88802b299270 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2bf/0x370 fs/file.c:1056 2 locks held by syz.2.18/5119: #0: ffff88807e1e6af0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2bf/0x370 fs/file.c:1056 #1: ffff88805c9b0298 (&sb->s_type->i_mutex_key#21){.+.+}-{3:3}, at: iterate_dir+0x10d/0x560 fs/readdir.c:55 1 lock held by syz.2.18/5120: #0: ffff88807e1e6af0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2bf/0x370 fs/file.c:1056 2 locks held by syz.3.19/5144: #0: ffff88807a9e2370 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2bf/0x370 fs/file.c:1056 #1: ffff88805c9b08f0 (&sb->s_type->i_mutex_key#21){.+.+}-{3:3}, at: iterate_dir+0x10d/0x560 fs/readdir.c:55 1 lock held by syz.3.19/5145: #0: ffff88807a9e2370 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2bf/0x370 fs/file.c:1056 2 locks held by syz.4.20/5177: #0: ffff888079145c70 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2bf/0x370 fs/file.c:1056 #1: ffff88805c9b0f48 (&sb->s_type->i_mutex_key#21){.+.+}-{3:3}, at: iterate_dir+0x10d/0x560 fs/readdir.c:55 1 lock held by syz.4.20/5178: #0: ffff888079145c70 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2bf/0x370 fs/file.c:1056 2 locks held by syz.5.21/5206: #0: ffff88802407e0f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2bf/0x370 fs/file.c:1056 #1: ffff88805c9b15a0 (&sb->s_type->i_mutex_key#21){.+.+}-{3:3}, at: iterate_dir+0x10d/0x560 fs/readdir.c:55 1 lock held by syz.5.21/5207: #0: ffff88802407e0f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2bf/0x370 fs/file.c:1056 2 locks held by syz.6.22/5234: #0: ffff8880295c59f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2bf/0x370 fs/file.c:1056 #1: ffff88805c9b1bf8 (&sb->s_type->i_mutex_key#21){.+.+}-{3:3}, at: iterate_dir+0x10d/0x560 fs/readdir.c:55 1 lock held by syz.6.22/5236: #0: ffff8880295c59f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2bf/0x370 fs/file.c:1056 2 locks held by syz.7.23/5271: #0: ffff888079101c70 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2bf/0x370 fs/file.c:1056 #1: ffff88806ef78f48 (&sb->s_type->i_mutex_key#21){.+.+}-{3:3}, at: iterate_dir+0x10d/0x560 fs/readdir.c:55 1 lock held by syz.7.23/5272: #0: ffff888079101c70 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2bf/0x370 fs/file.c:1056 2 locks held by syz.8.24/5300: #0: ffff8880789cfc70 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2bf/0x370 fs/file.c:1056 #1: ffff88806ef795a0 (&sb->s_type->i_mutex_key#21){.+.+}-{3:3}, at: iterate_dir+0x10d/0x560 fs/readdir.c:55 1 lock held by syz.8.24/5301: #0: ffff8880789cfc70 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2bf/0x370 fs/file.c:1056 2 locks held by syz.9.25/5329: #0: ffff888078120ff0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2bf/0x370 fs/file.c:1056 #1: ffff88805c9b2250 (&sb->s_type->i_mutex_key#21){.+.+}-{3:3}, at: iterate_dir+0x10d/0x560 fs/readdir.c:55 1 lock held by syz.9.25/5330: #0: ffff888078120ff0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2bf/0x370 fs/file.c:1056 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 27 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106 nmi_cpu_backtrace+0x397/0x3d0 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+0xe0f/0xe50 kernel/hung_task.c:369 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 9 Comm: kworker/u4:0 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: phy26 ieee80211_iface_work RIP: 0010:constant_test_bit arch/x86/include/asm/bitops.h:207 [inline] RIP: 0010:test_bit include/asm-generic/bitops/instrumented-non-atomic.h:135 [inline] RIP: 0010:ieee80211_iface_work+0xb3/0xc60 net/mac80211/iface.c:1500 Code: 24 50 1c 00 00 4c 89 f7 be 08 00 00 00 e8 05 57 8e f8 4c 89 f0 48 c1 e8 03 80 3c 18 00 74 08 4c 89 f7 e8 60 55 8e f8 4d 8b 36 <4c> 89 f6 48 83 e6 01 31 ff e8 8f f0 49 f8 49 83 e6 01 75 28 4d 8d RSP: 0018:ffffc90000ce7bd0 EFLAGS: 00000246 RAX: 1ffff1100f43d53e RBX: dffffc0000000000 RCX: ffffffff892ddf3b RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff88807a1ea9f0 RBP: ffffc90000ce7db8 R08: dffffc0000000000 R09: ffffed100f43d53f R10: ffffed100f43d53f R11: 1ffff1100f43d53e R12: ffff88807a1e8da0 R13: ffff8880169c3f18 R14: 0000000000000000 R15: ffff88805697d7c0 FS: 0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f133874ad58 CR3: 000000007e5e4000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: process_one_work+0x863/0x1000 kernel/workqueue.c:2310 worker_thread+0xaa8/0x12a0 kernel/workqueue.c:2457 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287