rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: (detected by 1, t=10502 jiffies, g=11781, q=213 ncpus=2) rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4294962616-4294952114), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 10502 jiffies! g11781 f0x2 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:27464 pid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x14e2/0x4580 kernel/sched/core.c:6700 preempt_schedule_common+0x82/0xc0 kernel/sched/core.c:6867 preempt_schedule+0xab/0xc0 kernel/sched/core.c:6891 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk_64.S:45 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] _raw_spin_unlock_irqrestore+0xfa/0x110 kernel/locking/spinlock.c:194 debug_object_assert_init+0x1f1/0x2f0 lib/debugobjects.c:900 debug_timer_assert_init kernel/time/timer.c:792 [inline] debug_assert_init kernel/time/timer.c:837 [inline] __mod_timer+0x55/0xdb0 kernel/time/timer.c:1020 schedule_timeout+0x15b/0x280 kernel/time/timer.c:2166 rcu_gp_fqs_loop+0x302/0x1560 kernel/rcu/tree.c:1663 rcu_gp_kthread+0x99/0x380 kernel/rcu/tree.c:1862 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 rcu: Stack dump where RCU GP kthread last ran: CPU: 1 PID: 6589 Comm: syz.1.209 Not tainted 6.6.93-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:raw_spin_rq_unlock_irq+0x13/0x90 kernel/sched/sched.h:1385 Code: 0f 48 8d 65 d8 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 b2 60 08 09 66 90 41 57 41 56 53 66 90 e8 a4 fc 11 09 e8 1f 44 2e 00 fb 5b <41> 5e 41 5f c3 f3 0f 1e fa 49 be 00 00 00 00 00 fc ff df 49 89 ff RSP: 0018:ffffc9000f31f8c8 EFLAGS: 00000282 RAX: 8736b0acbc33a900 RBX: ffff8880b8f3d188 RCX: 8736b0acbc33a900 RDX: dffffc0000000000 RSI: ffffffff8aaab2c0 RDI: ffffffff8afc6780 RBP: ffffc9000f31fae8 R08: ffffffff8e49a76f R09: 1ffffffff1c934ed R10: dffffc0000000000 R11: fffffbfff1c934ee R12: dffffc0000000000 R13: ffff8880b8f3c440 R14: ffff88802bcc3c00 R15: ffff88802bcc3c00 FS: 00007f47453ef6c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c2c6100 CR3: 000000002f85a000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __schedule+0x172e/0x4580 kernel/sched/core.c:6704 schedule+0xbd/0x170 kernel/sched/core.c:6774 futex_wait_queue+0x138/0x1b0 kernel/futex/waitwake.c:355 futex_wait+0x19f/0x530 kernel/futex/waitwake.c:656 do_futex+0x2ff/0x3e0 kernel/futex/syscalls.c:106 __do_sys_futex kernel/futex/syscalls.c:183 [inline] __se_sys_futex+0x36f/0x3f0 kernel/futex/syscalls.c:164 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f474458e929 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:00007f47453ef0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: ffffffffffffffda RBX: 00007f47447b5fa8 RCX: 00007f474458e929 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f47447b5fa8 RBP: 00007f47447b5fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f47447b5fac R13: 0000000000000000 R14: 00007ffe89663200 R15: 00007ffe896632e8