INFO: task syz.2.145:843 blocked for more than 122 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.145 state:D stack:0 pid:843 tgid:842 ppid:291 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5945 [inline] __schedule+0x1322/0x1df0 kernel/sched/core.c:7791 __schedule_loop kernel/sched/core.c:7872 [inline] schedule+0xc6/0x240 kernel/sched/core.c:7887 request_wait_answer fs/fuse/dev.c:476 [inline] __fuse_request_send fs/fuse/dev.c:491 [inline] __fuse_simple_request+0xdb1/0x1980 fs/fuse/dev.c:586 fuse_simple_request fs/fuse/fuse_i.h:1248 [inline] fuse_lookup_name+0x2db/0x990 fs/fuse/dir.c:526 fuse_lookup+0x2ad/0x18f0 fs/fuse/dir.c:624 lookup_one_qstr_excl+0x129/0x280 fs/namei.c:1633 do_rmdir+0x1b9/0x560 fs/namei.c:4388 __do_sys_rmdir fs/namei.c:4418 [inline] __se_sys_rmdir fs/namei.c:4416 [inline] __x64_sys_rmdir+0x4b/0x60 fs/namei.c:4416 x64_sys_call+0xaf7/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:85 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0x58/0xf0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7fb5b338eec9 RSP: 002b:00007fb5b4198038 EFLAGS: 00000246 ORIG_RAX: 0000000000000054 RAX: ffffffffffffffda RBX: 00007fb5b35e5fa0 RCX: 00007fb5b338eec9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000200000000040 RBP: 00007fb5b3411f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fb5b35e6038 R14: 00007fb5b35e5fa0 R15: 00007ffe29bb7a18 NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 16eb8ae5e642bf775817a16571acbfa82b92c919 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Call Trace: __dump_stack+0x21/0x30 lib/dump_stack.c:94 dump_stack_lvl+0x10c/0x190 lib/dump_stack.c:120 dump_stack+0x19/0x20 lib/dump_stack.c:129 nmi_cpu_backtrace+0x2bf/0x2d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x142/0x2c0 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:41 trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:267 [inline] watchdog+0xd8f/0xed0 kernel/hung_task.c:423 kthread+0x2ca/0x370 kernel/kthread.c:389 ret_from_fork+0x67/0xa0 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted syzkaller #0 16eb8ae5e642bf775817a16571acbfa82b92c919 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 RIP: 0010:__to_kthread kernel/kthread.c:93 [inline] RIP: 0010:kthread_is_per_cpu+0x32/0xf0 kernel/kthread.c:609 Code: 41 57 41 56 53 49 89 fe 49 bf 00 00 00 00 00 fc ff df e8 71 4f 2e 00 49 8d 9e 20 07 00 00 48 89 d8 48 c1 e8 03 42 80 3c 38 00 <74> 08 48 89 df e8 d4 bc 84 00 48 8b 1b 48 85 db 74 39 49 83 c6 2c RSP: 0018:ffffc900002306f8 EFLAGS: 00000046 RAX: 1ffff110216ee804 RBX: ffff88810b774020 RCX: ffff888103669300 RDX: 0000000000000100 RSI: ffffc90000230bf0 RDI: ffff88810b773900 RBP: ffffc90000230710 R08: ffff8881f6e50750 R09: 0000000000000004 R10: dffffc0000000000 R11: fffff520000460f4 R12: ffff8881f6f4fb80 R13: dffffc0000000000 R14: ffff88810b773900 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fc0e21b4198 CR3: 000000010aebc000 CR4: 00000000003526b0 Call Trace: can_migrate_task+0x226/0xcf0 kernel/sched/fair.c:9656 detach_tasks kernel/sched/fair.c:9841 [inline] sched_balance_rq+0x2a6c/0x5060 kernel/sched/fair.c:12063 sched_balance_domains+0x4b4/0xa10 kernel/sched/fair.c:12495 _nohz_idle_balance+0x3e3/0x5a0 kernel/sched/fair.c:12946 nohz_idle_balance kernel/sched/fair.c:12989 [inline] sched_balance_softirq+0x8a/0x170 kernel/sched/fair.c:13224 handle_softirqs+0x1ab/0x630 kernel/softirq.c:621 __do_softirq kernel/softirq.c:659 [inline] invoke_softirq kernel/softirq.c:476 [inline] __irq_exit_rcu+0x48/0xc0 kernel/softirq.c:708 irq_exit_rcu+0xd/0x30 kernel/softirq.c:720 instr_sysvec_call_function_single arch/x86/kernel/smp.c:266 [inline] sysvec_call_function_single+0x7f/0x90 arch/x86/kernel/smp.c:266 asm_sysvec_call_function_single+0x1f/0x30 arch/x86/include/asm/idtentry.h:709 RIP: 0010:pv_native_safe_halt+0x17/0x20 arch/x86/kernel/paravirt.c:106 Code: cc cc cc b8 e2 cc 84 44 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d c3 02 3a 00 f3 0f 1e fa 55 48 89 e5 fb f4 <5d> e9 d3 54 02 00 cc cc cc b8 00 00 00 00 90 90 90 90 90 90 90 90 RSP: 0018:ffffc900001a7e00 EFLAGS: 000002c2 RAX: ffff8881f6f00000 RBX: ffff888103669300 RCX: ffffffff858d50be RDX: 0000000000000001 RSI: 0000000000000004 RDI: 000000000013bb5c RBP: ffffc900001a7e00 R08: ffff8881f6f39733 R09: 1ffff1103ede72e6 R10: dffffc0000000000 R11: ffffed103ede72e7 R12: 1ffff110206cd260 R13: 0000000000000001 R14: 0000000000000000 R15: ffffffff87cb1fa8 arch_safe_halt arch/x86/include/asm/paravirt.h:112 [inline] default_idle+0x17/0x30 arch/x86/kernel/process.c:754 arch_cpu_idle+0xd/0x20 arch/x86/kernel/process.c:791 default_idle_call+0x3f/0x80 kernel/sched/idle.c:117 cpuidle_idle_call kernel/sched/idle.c:185 [inline] do_idle+0x1a0/0x470 kernel/sched/idle.c:326 cpu_startup_entry+0x48/0x70 kernel/sched/idle.c:424 start_secondary+0x12e/0x140 arch/x86/kernel/smpboot.c:314 common_startup_64+0x13b/0x157