rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-....: (10500 ticks this GP) idle=961/1/0x4000000000000000 softirq=6659/6659 fqs=5246 (t=10502 jiffies g=6305 q=21258) NMI backtrace for cpu 1 CPU: 1 PID: 4345 Comm: syz.0.16 Not tainted 5.15.185-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106 nmi_cpu_backtrace+0x397/0x3d0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline] rcu_dump_cpu_stacks+0x22f/0x380 kernel/rcu/tree_stall.h:349 print_cpu_stall+0x31d/0x5f0 kernel/rcu/tree_stall.h:633 check_cpu_stall kernel/rcu/tree_stall.h:727 [inline] rcu_pending kernel/rcu/tree.c:3932 [inline] rcu_sched_clock_irq+0x6d8/0x1110 kernel/rcu/tree.c:2619 update_process_times+0x193/0x200 kernel/time/timer.c:1818 tick_sched_handle kernel/time/tick-sched.c:254 [inline] tick_sched_timer+0x37d/0x560 kernel/time/tick-sched.c:1473 __run_hrtimer kernel/time/hrtimer.c:1690 [inline] __hrtimer_run_queues+0x4fe/0xc40 kernel/time/hrtimer.c:1754 hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1816 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline] __sysvec_apic_timer_interrupt+0x137/0x4a0 arch/x86/kernel/apic/apic.c:1114 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline] sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1108 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:__put_user_nocheck_4+0x5/0x11 Code: 48 39 d9 73 54 0f 01 cb 66 89 01 31 c9 0f 01 ca c3 90 90 90 90 90 48 bb fd ef ff ff ff 7f 00 00 48 39 d9 73 34 0f 01 cb 89 01 <31> c9 0f 01 ca c3 90 90 90 90 90 90 48 bb f9 ef ff ff ff 7f 00 00 RSP: 0018:ffffc9000321fb18 EFLAGS: 00040206 RAX: 0000000000000003 RBX: 00007ffd0802dc00 RCX: 00007ffd0802dac0 RDX: 0000000000000003 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc9000321fcb0 R08: 0000000000000000 R09: fffffbfff1775e66 R10: fffffbfff1775e66 R11: 1ffffffff1775e60 R12: dffffc0000000000 R13: 00007ffd0802d8c0 R14: ffff88807e719788 R15: 0000000000000000 save_xstate_epilog arch/x86/kernel/fpu/signal.c:131 [inline] copy_fpstate_to_sigframe+0x9bf/0xb90 arch/x86/kernel/fpu/signal.c:217 get_sigframe arch/x86/kernel/signal.c:295 [inline] __setup_rt_frame arch/x86/kernel/signal.c:471 [inline] setup_rt_frame arch/x86/kernel/signal.c:780 [inline] handle_signal arch/x86/kernel/signal.c:824 [inline] arch_do_signal_or_restart+0x67a/0x1300 arch/x86/kernel/signal.c:869 handle_signal_work kernel/entry/common.c:154 [inline] exit_to_user_mode_loop+0x9e/0x130 kernel/entry/common.c:178 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:214 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f479e5a7929 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffd0802dca8 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 00007f479e7cefa8 RCX: 00007f479e5a7929 RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f479e7cefac RBP: 0000000000000000 R08: 0011f66547fa4fcc R09: 000000070802df9f R10: 0000000000000005 R11: 0000000000000246 R12: 00007f479e7cefac R13: 00007f479e7cefa0 R14: 0000000000000095 R15: 0000000000000003