syzbot

INFO: task syz.2.17:381 blocked for more than 122 seconds.
      Not tainted 6.12.38-syzkaller-g3f3a5c5e782d #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.17        state:D stack:0     pid:381   tgid:381   ppid:371    flags:0x00004006
Call Trace:
 <TASK>
 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_flush+0x909/0x1d50 fs/fuse/file.c:582
 filp_flush fs/open.c:1550 [inline]
 filp_close+0xbd/0x160 fs/open.c:1563
 __range_close fs/file.c:712 [inline]
 __close_range+0x50e/0x6c0 fs/file.c:769
 __do_sys_close_range fs/open.c:1616 [inline]
 __se_sys_close_range fs/open.c:1613 [inline]
 __x64_sys_close_range+0x7e/0x90 fs/open.c:1613
 x64_sys_call+0x1686/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:437
 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: 0033:0x7fa6d378ebe9
RSP: 002b:00007ffe9ee86608 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: ffffffffffffffda RBX: 0000000000008029 RCX: 00007fa6d378ebe9
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007fa6d39b7da0 R08: 0000000000000001 R09: 0000000c9ee868ff
R10: 0000001b33220000 R11: 0000000000000246 R12: 00007fa6d39b5fac
R13: 00007fa6d39b5fa0 R14: ffffffffffffffff R15: 00007ffe9ee86720
 </TASK>
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 37 Comm: khungtaskd Not tainted 6.12.38-syzkaller-g3f3a5c5e782d #0 c9247809a66a5ebb3467d1c2e99b1dedbd707993
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
 <TASK>
 __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
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted 6.12.38-syzkaller-g3f3a5c5e782d #0 c9247809a66a5ebb3467d1c2e99b1dedbd707993
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:sched_balance_domains+0x157/0xa10 kernel/sched/fair.c:12435
Code: 85 28 08 00 00 44 3b 33 0f 95 c0 45 85 f6 0f 94 c1 08 c1 0f b6 c1 89 44 24 04 48 c7 c0 c0 b9 20 87 48 c1 e8 03 42 80 3c 28 00 <74> 0c 48 c7 c7 c0 b9 20 87 e8 db 21 7d 00 b8 70 17 00 00 48 03 05
RSP: 0018:ffffc90000230ce0 EFLAGS: 00000246
RAX: 1ffffffff0e41738 RBX: ffff8881f6f506a0 RCX: dffffc0000000000
RDX: 0000000000000100 RSI: 0000000000000001 RDI: ffff8881f6f4f980
RBP: ffffc90000230df0 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff520000461b0 R12: ffff8881f6f4f980
R13: dffffc0000000000 R14: 1ffff1103edea0b5 R15: 1ffff920000461ac
FS:  0000000000000000(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055828aaac478 CR3: 000000011cd8c000 CR4: 00000000003526b0
Call Trace:
 <IRQ>
 _nohz_idle_balance+0x3e3/0x5a0 kernel/sched/fair.c:12924
 nohz_idle_balance kernel/sched/fair.c:12967 [inline]
 sched_balance_softirq+0x8a/0x170 kernel/sched/fair.c:13195
 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
 </IRQ>
 <TASK>
 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 39 ce 1d be 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 83 91 3b 00 f3 0f 1e fa 55 48 89 e5 fb f4 <5d> c3 cc cc cc cc cc cc cc b8 00 00 00 00 90 90 90 90 90 90 90 90
RSP: 0018:ffffc900001a7e00 EFLAGS: 000002c6
RAX: ffff8881f6f00000 RBX: ffff88810366cc00 RCX: ffffffff858bc09e
RDX: 0000000000000001 RSI: 0000000000000004 RDI: 0000000000030d64
RBP: ffffc900001a7e00 R08: ffff8881f6f39733 R09: 1ffff1103ede72e6
R10: dffffc0000000000 R11: ffffed103ede72e7 R12: 1ffff110206cd980
R13: 0000000000000001 R14: 0000000000000000 R15: ffffffff87cad828
 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
 </TASK>