INFO: task syz.9.5734:27871 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.9.5734 state:D stack:28584 pid:27871 ppid:23211 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x1553/0x45a0 kernel/sched/core.c:6700 schedule+0xbd/0x170 kernel/sched/core.c:6774 request_wait_answer fs/fuse/dev.c:407 [inline] __fuse_request_send fs/fuse/dev.c:426 [inline] fuse_simple_request+0x1204/0x1c70 fs/fuse/dev.c:513 fuse_flush+0x667/0x8b0 fs/fuse/file.c:549 filp_flush fs/open.c:1533 [inline] filp_close+0xb1/0x150 fs/open.c:1546 __range_close fs/file.c:698 [inline] __close_range+0x368/0x660 fs/file.c:755 __do_sys_close_range fs/open.c:1599 [inline] __se_sys_close_range fs/open.c:1596 [inline] __x64_sys_close_range+0x7a/0x90 fs/open.c:1596 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f0e3ab9bf79 RSP: 002b:00007f0e3ba51028 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: ffffffffffffffda RBX: 00007f0e3ae16090 RCX: 00007f0e3ab9bf79 RDX: 0000000000000000 RSI: ffffffffffffffff RDI: 0000000000000000 RBP: 00007f0e3ac327e0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f0e3ae16128 R14: 00007f0e3ae16090 R15: 00007fffcfdd1938 Showing all locks held in the system: 1 lock held by khungtaskd/29: #0: ffffffff8d131fa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #0: ffffffff8d131fa0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #0: ffffffff8d131fa0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633 3 locks held by udevd/5140: #0: ffff8880b8f3c018 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:559 #1: ffff8880b8f289c0 (psi_seq){-.-.}-{0:0}, at: psi_sched_switch kernel/sched/stats.h:189 [inline] #1: ffff8880b8f289c0 (psi_seq){-.-.}-{0:0}, at: __schedule+0x2176/0x45a0 kernel/sched/core.c:6695 #2: ffffffff8d131fa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #2: ffffffff8d131fa0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #2: ffffffff8d131fa0 (rcu_read_lock){....}-{1:2}, at: dput+0x3b/0x1e0 fs/dcache.c:904 2 locks held by getty/5530: #0: ffff88802d45e0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900015d72f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x433/0x1390 drivers/tty/n_tty.c:2217 2 locks held by kworker/1:0/18973: #0: ffff8880b8f3c018 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:559 #1: ffff8880b8f289c0 (psi_seq){-.-.}-{0:0}, at: psi_sched_switch kernel/sched/stats.h:189 [inline] #1: ffff8880b8f289c0 (psi_seq){-.-.}-{0:0}, at: __schedule+0x2176/0x45a0 kernel/sched/core.c:6695 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 29 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026 Call Trace: dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106 nmi_cpu_backtrace+0x3a6/0x3e0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline] watchdog+0xf3d/0xf80 kernel/hung_task.c:379 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 19596 Comm: kworker/u4:13 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026 Workqueue: bat_events batadv_iv_send_outstanding_bat_ogm_packet RIP: 0010:hlock_class kernel/locking/lockdep.c:228 [inline] RIP: 0010:mark_lock+0x9c/0x320 kernel/locking/lockdep.c:4656 Code: 89 c7 41 81 e7 ff 1f 00 00 c1 e8 03 25 f8 03 00 00 48 8d b8 00 f5 1b 91 be 08 00 00 00 e8 1c 5f 76 00 4c 0f a3 3d a4 15 b3 0f <73> 10 49 69 c7 d0 00 00 00 4c 8d b8 c0 73 b2 90 eb 24 48 c7 c0 80 RSP: 0018:ffffc90004a9f5e0 EFLAGS: 00000057 RAX: 0000000000000001 RBX: ffff88805f081e00 RCX: ffffffff8168df54 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff911bf500 RBP: 0000000000000009 R08: ffffffff911bf507 R09: 1ffffffff2237ea0 R10: dffffc0000000000 R11: fffffbfff2237ea1 R12: 0000000000000200 R13: dffffc0000000000 R14: ffff88805f082958 R15: 0000000000000021 FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055ca82df10c8 CR3: 000000000cf32000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 000000000000000c DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: mark_usage kernel/locking/lockdep.c:4599 [inline] __lock_acquire+0xd5c/0x7d40 kernel/locking/lockdep.c:5091 lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5754 rcu_lock_acquire include/linux/rcupdate.h:334 [inline] rcu_read_lock include/linux/rcupdate.h:786 [inline] batadv_iv_ogm_slide_own_bcast_window net/batman-adv/bat_iv_ogm.c:753 [inline] batadv_iv_ogm_schedule_buff net/batman-adv/bat_iv_ogm.c:824 [inline] batadv_iv_ogm_schedule+0x40b/0xf10 net/batman-adv/bat_iv_ogm.c:867 batadv_iv_send_outstanding_bat_ogm_packet+0x733/0x850 net/batman-adv/bat_iv_ogm.c:1711 process_one_work kernel/workqueue.c:2634 [inline] process_scheduled_works+0xa5d/0x15d0 kernel/workqueue.c:2711 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293