INFO: task syz.1.4693:15120 blocked for more than 122 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.4693      state:D stack:0     pid:15120 tgid:15119 ppid:13794  flags:0x00004004
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
 super_lock+0x150/0x300 fs/super.c:115
 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: 0033:0x7f3f4ed8f6c9
RSP: 002b:00007f3f4fbcc038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f3f4efe5fa0 RCX: 00007f3f4ed8f6c9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f3f4efe5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f3f4efe6038 R14: 00007f3f4efe5fa0 R15: 00007ffff940acc8
 </TASK>
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:
 <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: 18 Comm: rcu_preempt Not tainted syzkaller #0 0b5ffdee5fcd2f7749818d1ff954e9c21353764e
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:arch_static_branch arch/x86/include/asm/jump_label.h:36 [inline]
RIP: 0010:static_key_false include/linux/jump_label.h:230 [inline]
RIP: 0010:native_write_msr arch/x86/include/asm/msr.h:149 [inline]
RIP: 0010:wrmsrl arch/x86/include/asm/msr.h:264 [inline]
RIP: 0010:native_x2apic_icr_write arch/x86/include/asm/apic.h:233 [inline]
RIP: 0010:__x2apic_send_IPI_dest arch/x86/kernel/apic/x2apic_phys.c:113 [inline]
RIP: 0010:x2apic_send_IPI+0x76/0xe0 arch/x86/kernel/apic/x2apic_phys.c:50
Code: 89 f0 48 c1 e8 03 42 0f b6 04 20 84 c0 75 44 41 8b 16 0f ae f0 0f ae e8 83 fb 02 b8 00 04 00 00 0f 45 c3 b9 30 08 00 00 0f 30 <66> 90 5b 41 5c 41 5e 41 5f 5d c3 cc cc cc cc cc 89 fe 41 89 fe 48
RSP: 0018:ffffc90000127760 EFLAGS: 00000006
RAX: 00000000000000fb RBX: 00000000000000fb RCX: 0000000000000830
RDX: 0000000000000000 RSI: 00000000000000fb RDI: 0000000000000000
RBP: ffffc90000127780 R08: ffffc90000127727 R09: 1ffff92000024ee4
R10: 0000000000000000 R11: ffffffff81421720 R12: dffffc0000000000
R13: dffffc0000000000 R14: ffff8881f6e21168 R15: ffffffff86f6cb80
FS:  0000000000000000(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005618c490cb98 CR3: 00000000072a8000 CR4: 00000000003526b0
Call Trace:
 <TASK>
 __apic_send_IPI arch/x86/include/asm/apic.h:430 [inline]
 native_send_call_func_single_ipi+0x12/0x20 arch/x86/kernel/apic/ipi.c:78
 arch_send_call_function_single_ipi arch/x86/include/asm/smp.h:94 [inline]
 send_call_function_single_ipi kernel/smp.c:118 [inline]
 __smp_call_single_queue+0xd5/0x390 kernel/smp.c:411
 irq_work_queue_on+0x150/0x210 kernel/irq_work.c:173
 tell_cpu_to_push+0x5ac/0x650 kernel/sched/rt.c:2423
 pull_rt_task kernel/sched/rt.c:2489 [inline]
 balance_rt+0x29b/0x440 kernel/sched/rt.c:1741
 prev_balance kernel/sched/core.c:6577 [inline]
 __pick_next_task kernel/sched/core.c:6619 [inline]
 pick_next_task kernel/sched/core.c:7125 [inline]
 __schedule+0x966/0x1df0 kernel/sched/core.c:7718
 __schedule_loop kernel/sched/core.c:7872 [inline]
 schedule+0xc6/0x240 kernel/sched/core.c:7887
 schedule_timeout+0x139/0x3a0 kernel/time/timer.c:2619
 rcu_gp_fqs_loop+0x2f2/0x12f0 kernel/rcu/tree.c:2053
 rcu_gp_kthread+0x99/0x380 kernel/rcu/tree.c:2255
 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>