INFO: task syz-executor:18488 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:21672 pid:18488 tgid:18488 ppid:1 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0x165/0x360 kernel/sched/core.c:7026 bit_wait+0x11/0xd0 kernel/sched/wait_bit.c:240 __wait_on_bit+0xb9/0x310 kernel/sched/wait_bit.c:52 out_of_line_wait_on_bit+0x123/0x170 kernel/sched/wait_bit.c:67 wait_on_bit include/linux/wait_bit.h:77 [inline] gfs2_glock_wait+0xbd/0x2a0 fs/gfs2/glock.c:1335 gfs2_glock_nq_init fs/gfs2/glock.h:252 [inline] __gfs2_lookup+0x117/0x270 fs/gfs2/inode.c:984 __lookup_slow+0x297/0x3d0 fs/namei.c:1816 lookup_slow+0x53/0x70 fs/namei.c:1833 walk_component+0x2d2/0x400 fs/namei.c:2151 lookup_last fs/namei.c:2652 [inline] path_lookupat+0x163/0x430 fs/namei.c:2676 filename_lookup+0x212/0x570 fs/namei.c:2705 user_path_at+0x3a/0x60 fs/namei.c:3215 ksys_umount fs/namespace.c:2061 [inline] __do_sys_umount fs/namespace.c:2069 [inline] __se_sys_umount fs/namespace.c:2067 [inline] __x64_sys_umount+0xee/0x160 fs/namespace.c:2067 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f91a21901f7 RSP: 002b:00007ffc92a4e768 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: ffffffffffffffda RBX: 00007f91a2211d7d RCX: 00007f91a21901f7 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffc92a4e820 RBP: 00007ffc92a4e820 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffc92a4f910 R13: 00007f91a2211d7d R14: 00000000001d4039 R15: 00007ffc92a51ad0 Showing all locks held in the system: 4 locks held by rcu_exp_gp_kthr/18: #0: ffff8880b883a018 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xad/0x140 kernel/sched/core.c:646 #1: ffffffff8dd3b160 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #1: ffffffff8dd3b160 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #1: ffffffff8dd3b160 (rcu_read_lock){....}-{1:3}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2074 [inline] #1: ffffffff8dd3b160 (rcu_read_lock){....}-{1:3}, at: bpf_trace_run4+0x19c/0x4a0 kernel/trace/bpf_trace.c:2118 #2: ffff888140a846e8 (&p->pi_lock){-.-.}-{2:2}, at: class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:557 [inline] #2: ffff888140a846e8 (&p->pi_lock){-.-.}-{2:2}, at: try_to_wake_up+0x67/0x12b0 kernel/sched/core.c:4181 #3: ffff8880b883a018 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xad/0x140 kernel/sched/core.c:646 1 lock held by khungtaskd/31: #0: ffffffff8dd3b160 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8dd3b160 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8dd3b160 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by getty/5592: #0: ffff8880334150a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 3 locks held by kworker/1:3/5908: #0: ffff88801a011948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff88801a011948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc9000433fbc0 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc9000433fbc0 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffff8880552b5240 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x26b/0x3180 drivers/net/netdevsim/fib.c:1490 1 lock held by syz-executor/18488: #0: ffff888031a12908 (&type->i_mutex_dir_key#17){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:994 [inline] #0: ffff888031a12908 (&type->i_mutex_dir_key#17){++++}-{4:4}, at: lookup_slow+0x46/0x70 fs/namei.c:1832 1 lock held by syz.8.4866/25650: #0: ffff8880786fc260 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:330 [inline] #0: ffff8880786fc260 (&mm->mmap_lock){++++}-{4:4}, at: vm_mmap_pgoff+0x211/0x4d0 mm/util.c:578 2 locks held by syz.8.4866/25651: ============================================= 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 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+0x439/0x7d0 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: 15423 Comm: kworker/1:2 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Workqueue: events_long br_fdb_cleanup RIP: 0010:hlist_add_head include/linux/list.h:1048 [inline] RIP: 0010:enqueue_timer+0x86/0x560 kernel/time/timer.c:616 Code: 48 b9 00 00 00 00 00 fc ff df 80 3c 08 00 74 08 4c 89 e7 e8 8c 0b 78 00 4d 89 2c 24 4d 85 ed 74 2e e8 be 67 12 00 49 83 c5 08 <4c> 89 e8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 80 3c 08 00 74 RSP: 0018:ffffc90004e1f8b0 EFLAGS: 00000086 RAX: ffffffff81ac17a2 RBX: ffff8880b8925b28 RCX: ffff88802e5fdac0 RDX: 0000000000000000 RSI: ffff88807a845980 RDI: ffff8880b8925940 RBP: 0000000000000029 R08: ffffffff997842a3 R09: 1ffffffff32f0854 R10: dffffc0000000000 R11: fffffbfff32f0855 R12: ffff88807a845980 R13: ffff888069a7d988 R14: 0000000000000029 R15: 1ffff11017124b65 FS: 0000000000000000(0000) GS:ffff88812648a000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fd6f03b0e9c CR3: 0000000077f93000 CR4: 0000000000350ef0 Call Trace: __mod_timer+0xb28/0xf30 kernel/time/timer.c:-1 mod_delayed_work_on+0xf8/0x200 kernel/workqueue.c:2597 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+0x439/0x7d0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245