INFO: task syz.0.17:5913 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:24872 pid:5913 tgid:5913 ppid:5761 task_flags:0x400040 flags:0x00080003 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x1709/0x5530 kernel/sched/core.c:7234 __schedule_loop kernel/sched/core.c:7311 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7326 request_wait_answer fs/fuse/dev.c:743 [inline] __fuse_request_send fs/fuse/dev.c:757 [inline] fuse_chan_send+0x1068/0x1ad0 fs/fuse/dev.c:833 fuse_simple_request fs/fuse/fuse_i.h:1012 [inline] fuse_flush+0x677/0x8b0 fs/fuse/file.c:504 filp_flush+0xc0/0x190 fs/open.c:1471 filp_close+0x1d/0x40 fs/open.c:1484 __range_close fs/file.c:793 [inline] __do_sys_close_range fs/file.c:854 [inline] __se_sys_close_range+0x3d6/0x910 fs/file.c:818 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd06712de59 RSP: 002b:00007ffdd9287e88 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: ffffffffffffffda RBX: 00007ffdd9287f70 RCX: 00007fd06712de59 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 000000000001cabd R08: 0000000000000001 R09: 0000000000000000 R10: 0000001b2c020000 R11: 0000000000000246 R12: 00007ffdd9287fb0 R13: 00007fd0673b5fac R14: 000000000001cb3f R15: 00007fd0673b5fa0 Showing all locks held in the system: 1 lock held by khungtaskd/39: #0: ffffffff8dfc30c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8dfc30c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #0: ffffffff8dfc30c0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6777 3 locks held by kworker/u8:5/69: #0: ffff888032dab938 ((wq_completion)bat_events){+.+.}-{0:0}, at: process_one_work+0x8cd/0x12b0 kernel/workqueue.c:3301 #1: ffffc9000154fc60 ((work_completion)(&(&bat_priv->dat.work)->work)){+.+.}-{0:0}, at: process_one_work+0x8cd/0x12b0 kernel/workqueue.c:3301 #2: ffffffff8de591e0 (local_bh){.+.+}-{1:3}, at: __local_bh_disable_ip+0x3c/0x420 kernel/softirq.c:163 2 locks held by getty/5363: #0: ffff88803684e0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003cc62e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x460/0x1360 drivers/tty/n_tty.c:2211 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 39 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:122 nmi_trigger_cpumask_backtrace+0x17a/0x380 lib/nmi_backtrace.c:65 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] __sys_info lib/sys_info.c:158 [inline] sys_info+0x135/0x170 lib/sys_info.c:166 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline] watchdog+0xfd7/0x1030 kernel/hung_task.c:561 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 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: 69 Comm: kworker/u8:5 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Workqueue: bat_events batadv_dat_purge RIP: 0010:lockdep_enabled kernel/locking/lockdep.c:118 [inline] RIP: 0010:lock_is_held_type+0x1a/0x150 kernel/locking/lockdep.c:5935 Code: 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 55 41 57 41 56 41 55 41 54 53 bb ff ff ff ff 83 3d c6 6e 5b 04 00 <0f> 84 e4 00 00 00 65 8b 05 51 5e 44 07 85 c0 0f 85 d5 00 00 00 65 RSP: 0018:ffffc9000154f9b0 EFLAGS: 00000202 RAX: 0000000000000001 RBX: 00000000ffffffff RCX: ffff88801af98000 RDX: 0000000000000100 RSI: 00000000ffffffff RDI: ffffffff8dfc3180 RBP: ffffc9000154faf8 R08: ffffffff8afa7171 R09: 0000000000000000 R10: 0000000000000000 R11: ffff8880463e8f58 R12: ffff88801af98000 R13: dffffc0000000000 R14: ffff8880463e8f00 R15: ffff88801af984c4 FS: 0000000000000000(0000) GS:ffff888125fcd000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000559e00dc6190 CR3: 000000000ddb0000 CR4: 00000000003526f0 Call Trace: lock_is_held include/linux/lockdep.h:249 [inline] __might_resched+0x37/0x480 kernel/sched/core.c:9159 __rt_spin_lock kernel/locking/spinlock_rt.c:48 [inline] rt_spin_lock+0xc2/0x400 kernel/locking/spinlock_rt.c:57 spin_lock_bh include/linux/spinlock_rt.h:90 [inline] __batadv_dat_purge+0x131/0x400 net/batman-adv/distributed-arp-table.c:174 batadv_dat_purge+0x20/0x70 net/batman-adv/distributed-arp-table.c:205 process_one_work+0x93a/0x12b0 kernel/workqueue.c:3326 process_scheduled_works kernel/workqueue.c:3409 [inline] worker_thread+0xb05/0x10d0 kernel/workqueue.c:3490 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245