INFO: task syz.1.1008:3531 blocked for more than 122 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.1008 state:D stack:0 pid:3531 tgid:3530 ppid:289 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 schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:7944 rwsem_down_read_slowpath+0x6d1/0x1460 kernel/locking/rwsem.c:1136 __down_read_common kernel/locking/rwsem.c:1317 [inline] __down_read kernel/locking/rwsem.c:1330 [inline] down_read+0x8f/0xe0 kernel/locking/rwsem.c:1607 __super_lock fs/super.c:59 [inline] super_lock+0x231/0x300 fs/super.c:121 super_lock_shared fs/super.c:140 [inline] iterate_supers+0x8a/0x560 fs/super.c:934 ksys_sync+0x95/0x160 fs/sync.c:103 __ia32_sys_sync+0x12/0x20 fs/sync.c:114 x64_sys_call+0x2a58/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:163 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: 0033:0x7f7efd58f6c9 RSP: 002b:00007f7efe4ad038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007f7efd7e5fa0 RCX: 00007f7efd58f6c9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f7efd7e5fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f7efd7e6038 R14: 00007f7efd7e5fa0 R15: 00007ffd0c698c08 NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 0b5ffdee5fcd2f7749818d1ff954e9c21353764e Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 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 0b5ffdee5fcd2f7749818d1ff954e9c21353764e Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:update_group_capacity+0x0/0x9f0 kernel/sched/fair.c:10282 Code: 86 eb ff ff 5b 5d c3 cc cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 b8 f1 a4 97 36 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 55 48 89 e5 41 57 41 56 41 55 41 54 53 48 83 e4 e0 48 RSP: 0018:ffffc90000230818 EFLAGS: 00000297 RAX: 0000000000000001 RBX: 0000000000000001 RCX: ffffffff815f16f5 RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff888101a6dc00 RBP: ffffc90000230cd0 R08: ffff888103e5162f R09: 1ffff110207ca2c5 R10: dffffc0000000000 R11: ffffed10207ca2c6 R12: dffffc0000000000 R13: ffff888103e51600 R14: ffff8881f6f28e20 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 0000000110dc8000 CR4: 00000000003526b0 Call Trace: 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 5f ed 33 95 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d c3 e2 39 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: ffff88810366cc00 RCX: ffffffff858d70be RDX: 0000000000000001 RSI: 0000000000000004 RDI: 00000000002b0bdc RBP: ffffc900001a7e00 R08: ffff8881f6f39733 R09: 1ffff1103ede72e6 R10: dffffc0000000000 R11: ffffed103ede72e7 R12: 1ffff110206cd980 R13: 0000000000000001 R14: 0000000000000000 R15: ffffffff87cb2128 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