INFO: task syz.3.4252:20319 blocked for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.4252 state:D stack:24832 pid:20319 tgid:20319 ppid:12234 task_flags:0x400040 flags:0x00080003 Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0x1553/0x5240 kernel/sched/core.c:6911 __schedule_loop kernel/sched/core.c:6993 [inline] schedule+0x164/0x360 kernel/sched/core.c:7008 request_wait_answer fs/fuse/dev.c:585 [inline] __fuse_request_send fs/fuse/dev.c:599 [inline] __fuse_simple_request+0x121f/0x1c60 fs/fuse/dev.c:693 fuse_simple_request fs/fuse/fuse_i.h:1263 [inline] fuse_flush+0x673/0x8b0 fs/fuse/file.c:494 filp_flush+0xc0/0x190 fs/open.c:1469 filp_close+0x1d/0x40 fs/open.c:1482 __range_close fs/file.c:794 [inline] __do_sys_close_range fs/file.c:855 [inline] __se_sys_close_range+0x3d7/0x900 fs/file.c:819 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff8499dc819 RSP: 002b:00007fffdcfda9f8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: ffffffffffffffda RBX: 00007ff849c57da0 RCX: 00007ff8499dc819 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007ff849c57da0 R08: 0000000000000006 R09: 0000000000000000 R10: 00007ff849c57cb0 R11: 0000000000000246 R12: 000000000012b93f R13: 00007ff849c5609c R14: 000000000012b6c6 R15: 00007ff849c56090 Showing all locks held in the system: 7 locks held by kworker/0:0H/11: 1 lock held by khungtaskd/37: #0: ffffffff8ddcb9c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8ddcb9c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8ddcb9c0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 6 locks held by kworker/u8:4/67: 2 locks held by kworker/u8:6/149: 6 locks held by kworker/u8:10/1130: 1 lock held by klogd/5155: 3 locks held by udevd/5166: 2 locks held by getty/5554: #0: ffff888032f6c0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003e7e2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13c0 drivers/tty/n_tty.c:2211 6 locks held by kworker/u8:22/15625: 9 locks held by syz-executor/20496: 10 locks held by syz-executor/20869: 1 lock held by syz.7.4766/22170: #0: ffff8880b883b7e0 (&rq->__lock){-...}-{2:2}, at: spin_lock include/linux/spinlock_rt.h:45 [inline] #0: ffff8880b883b7e0 (&rq->__lock){-...}-{2:2}, at: remove_wait_queue+0x23/0x110 kernel/sched/wait.c:73 4 locks held by syz.4.4768/22173: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 37 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT_{RT,(full)} Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:161 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x135/0x170 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline] watchdog+0xfd9/0x1030 kernel/hung_task.c:515 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 11 Comm: kworker/0:0H Tainted: G L syzkaller #0 PREEMPT_{RT,(full)} Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Workqueue: events_highpri snd_vmidi_output_work RIP: 0010:rcu_note_context_switch+0x275/0xf40 kernel/rcu/tree_plugin.h:348 Code: e8 60 7d 80 00 4d 8b 3f 49 83 c7 70 4c 89 f8 48 c1 e8 03 80 3c 28 00 74 08 4c 89 ff e8 44 7d 80 00 49 85 1f 0f 84 53 0a 00 00 <49> 8d 9c 24 d0 04 00 00 48 89 d8 48 c1 e8 03 48 89 44 24 50 80 3c RSP: 0018:ffffc90000107530 EFLAGS: 00000002 RAX: 1ffffffff1bba28e RBX: 0000000000000001 RCX: 0000000000000001 RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffc900001074a0 RBP: dffffc0000000000 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffff52000020e94 R12: ffff88801c6c1e80 R13: ffff8880b883c768 R14: ffff8880b883c740 R15: ffffffff8ddd1470 FS: 0000000000000000(0000) GS:ffff888126336000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000002000 CR3: 000000003726c000 CR4: 00000000003526f0 Call Trace: __schedule+0x2b5/0x5240 kernel/sched/core.c:6794 preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:7095 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12 class_preempt_destructor include/linux/preempt.h:468 [inline] try_to_wake_up+0x832/0x1380 kernel/sched/core.c:4249 __wake_up_common kernel/sched/wait.c:108 [inline] __wake_up_common_lock+0x136/0x1e0 kernel/sched/wait.c:125 __snd_rawmidi_transmit_ack+0x27b/0x360 sound/core/rawmidi.c:1448 snd_rawmidi_transmit+0x7b/0xf0 sound/core/rawmidi.c:1492 snd_vmidi_output_work+0x1a5/0x3f0 sound/core/seq/seq_virmidi.c:151 process_one_work kernel/workqueue.c:3276 [inline] process_scheduled_works+0xb6e/0x18c0 kernel/workqueue.c:3359 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3440 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245