rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-...!: (10499 ticks this GP) idle=7ab/1/0x4000000000000000 softirq=5864/5864 fqs=2 
	(t=10501 jiffies g=5549 q=109)
rcu: rcu_preempt kthread starved for 10498 jiffies! g5549 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1
rcu: 	Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_preempt     state:R  running task     stack:27496 pid:   15 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5030 [inline]
 __schedule+0x11b8/0x43b0 kernel/sched/core.c:6376
 schedule+0x11b/0x1e0 kernel/sched/core.c:6459
 schedule_timeout+0x15c/0x280 kernel/time/timer.c:1914
 rcu_gp_fqs_loop+0x29e/0x11b0 kernel/rcu/tree.c:1972
 rcu_gp_kthread+0x98/0x350 kernel/rcu/tree.c:2145
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 4225 Comm: syz-executor738 Not tainted 5.15.185-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:validate_chain kernel/locking/lockdep.c:3795 [inline]
RIP: 0010:__lock_acquire+0x1942/0x7c60 kernel/locking/lockdep.c:5012
Code: 24 d8 00 00 00 0f 85 67 05 00 00 48 c7 c0 84 df 68 8d 48 c1 e8 03 42 0f b6 04 00 84 c0 0f 85 1e 52 00 00 83 3d 92 db 0c 0c 00 <48> 8b 5c 24 40 4c 8b b4 24 b0 00 00 00 0f 84 9a 40 00 00 48 8b 84
RSP: 0018:ffffc9000300fb20 EFLAGS: 00000002
RAX: 0000000000000000 RBX: ffffffff8f923f80 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8ff9b0c0
RBP: ffffc9000300fd70 R08: dffffc0000000000 R09: fffffbfff1ff3619
R10: fffffbfff1ff3619 R11: 1ffffffff1ff3618 R12: 9be2421a50ef4013
R13: ffff88801abfbb80 R14: 0000000050ef4013 R15: ffff88801abfc690
FS:  000055556eef83c0(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f9366ae2d60 CR3: 0000000074397000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 lock_acquire+0x197/0x3f0 kernel/locking/lockdep.c:5623
 rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:312
 rcu_read_lock include/linux/rcupdate.h:739 [inline]
 __task_pid_nr_ns+0x21/0x420 kernel/pid.c:497
 task_tgid_vnr include/linux/sched.h:1585 [inline]
 __ia32_sys_getpid+0x19/0x20 kernel/sys.c:945
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f9366ac8b37
Code: 0b e9 68 fe ff ff 48 83 c4 18 48 8d 3d c2 b9 08 00 5b 5d 41 5c 41 5d 41 5e 41 5f e9 63 b9 fd ff 0f 1f 00 b8 27 00 00 00 0f 05 <c3> 0f 1f 84 00 00 00 00 00 b8 6e 00 00 00 0f 05 c3 0f 1f 84 00 00
RSP: 002b:00007ffd1f04f808 EFLAGS: 00000202 ORIG_RAX: 0000000000000027
RAX: ffffffffffffffda RBX: 00007ffd1f04f970 RCX: 00007f9366ac8b37
RDX: 00007ffd1f04f840 RSI: 00007ffd1f04f970 RDI: 0000000000000021
RBP: 0000000000000000 R08: 00007f9366a82990 R09: 00007f9366a82990
R10: 0000000000000000 R11: 0000000000000202 R12: 00007f9366b21e3c
R13: 00007f9366b1b14e R14: 00007ffd1f04fe00 R15: 0000000000000000
 </TASK>
NMI backtrace for cpu 0
CPU: 0 PID: 4223 Comm: syz-executor738 Not tainted 5.15.185-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <IRQ>
 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
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:___might_sleep+0x180/0x600 kernel/sched/core.c:9607
Code: 03 00 00 45 03 7d 00 44 3b 7c 24 2c 75 61 48 c7 84 24 a0 00 00 00 00 00 00 00 9c 8f 84 24 a0 00 00 00 f6 84 24 a1 00 00 00 02 <74> 43 4c 8d 7a 2c 4c 89 f8 48 c1 e8 03 42 0f b6 04 20 84 c0 0f 85
RSP: 0018:ffffc90002eefb20 EFLAGS: 00000202
RAX: 0000000000000000 RBX: 1ffff920005ddf6c RCX: 8890d5d5a65b0d00
RDX: ffff88807e870000 RSI: ffffffff8a0b2460 RDI: ffffffff8a59a740
RBP: ffffc90002eefc30 R08: 0000000000000000 R09: fffff520005ddfc6
R10: fffff520005ddfc6 R11: 1ffff920005ddfc0 R12: dffffc0000000000
R13: ffff88807e87043c R14: 1ffff1100fd0e087 R15: 0000000000000000
 __might_fault+0x6b/0x110 mm/memory.c:5354
 __clear_user arch/x86/lib/usercopy_64.c:20 [inline]
 clear_user+0xd2/0x150 arch/x86/lib/usercopy_64.c:54
 copy_siginfo_to_user+0x57/0x80 kernel/signal.c:3369
 __setup_rt_frame arch/x86/kernel/signal.c:490 [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+0xd56/0x1300 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: 0033:0x7f9366acb229
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 d1 1d 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffd1f04fdc8 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 0000000000000003 RCX: 00007f9366acb229
RDX: 000020000006b000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 00007f9366a82990 R09: 00007f9366a82990
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f9366b21e3c
R13: 00007f9366b1b14e R14: 00007ffd1f04fe00 R15: 0000000000000000
 </TASK>
sched: RT throttling activated