rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: (detected by 1, t=10502 jiffies, g=8797, q=21 ncpus=2) rcu: All QSes seen, last rcu_preempt kthread activity 10503 (4294962545-4294952042), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 10504 jiffies! g8797 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 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:27776 pid:16 tgid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5409 [inline] __schedule+0xf15/0x5c70 kernel/sched/core.c:6736 __schedule_loop kernel/sched/core.c:6813 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6828 schedule_timeout+0x136/0x2a0 kernel/time/timer.c:2572 rcu_gp_fqs_loop+0x1eb/0xb00 kernel/rcu/tree.c:1663 rcu_gp_kthread+0x271/0x380 kernel/rcu/tree.c:1862 kthread+0x2c1/0x3a0 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 5181 Comm: syz-executor117 Not tainted 6.8.0-syzkaller-08951-gfe46a7dd189e #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 RIP: 0010:native_irq_disable arch/x86/include/asm/irqflags.h:37 [inline] RIP: 0010:arch_local_irq_disable arch/x86/include/asm/irqflags.h:72 [inline] RIP: 0010:arch_local_irq_save arch/x86/include/asm/irqflags.h:104 [inline] RIP: 0010:lock_acquire kernel/locking/lockdep.c:5750 [inline] RIP: 0010:lock_acquire+0x165/0x540 kernel/locking/lockdep.c:5719 Code: 83 e0 07 83 c0 03 38 c8 7c 08 84 c9 0f 85 91 03 00 00 8b 92 d4 0a 00 00 85 d2 0f 85 d6 00 00 00 9c 8f 44 24 08 48 8b 6c 24 08 48 c7 c7 00 ba 0c 8b e8 9e 0b 67 09 48 89 e8 45 89 e0 44 89 ea RSP: 0018:ffffc9000373fe08 EFLAGS: 00000246 RAX: 0000000000000007 RBX: 1ffff920006e7fc3 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff8b6e8820 RDI: ffff888022d564d4 RBP: 0000000000000246 R08: 0000000000000000 R09: fffffbfff1f3cdf2 R10: ffffffff8f9e6f97 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: ffffffff8d7b08e0 R15: 0000000000000000 FS: 000055555ad6f3c0(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020000280 CR3: 000000002abec000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_lock_acquire include/linux/rcupdate.h:298 [inline] rcu_read_lock include/linux/rcupdate.h:750 [inline] __task_pid_nr_ns+0x3f/0x500 kernel/pid.c:510 task_tgid_vnr include/linux/pid.h:294 [inline] __do_sys_getpid+0x1d/0x30 kernel/sys.c:960 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xd2/0x260 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x6d/0x75 RIP: 0033:0x7f9876dad387 Code: 0b e9 68 fe ff ff 48 83 c4 18 48 8d 3d 52 0f 09 00 5b 5d 41 5c 41 5d 41 5e 41 5f e9 43 d8 fd ff 0f 1f 00 b8 27 00 00 00 0f 05 0f 1f 84 00 00 00 00 00 31 f6 31 ff e9 c7 e5 02 00 0f 1f 80 00 RSP: 002b:00007ffcabd1cf48 EFLAGS: 00000206 ORIG_RAX: 0000000000000027 RAX: ffffffffffffffda RBX: 00007ffcabd1d0b0 RCX: 00007f9876dad387 RDX: 00007ffcabd1cf80 RSI: 00007ffcabd1d0b0 RDI: 0000000000000021 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 00000000000235ab R13: 00007ffcabd1d538 R14: 00007ffcabd1d590 R15: 00007ffcabd1d580