rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: (detected by 0, t=10502 jiffies, g=9869, q=32 ncpus=2) rcu: All QSes seen, last rcu_preempt kthread activity 10503 (4294959984-4294949481), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 10504 jiffies! g9869 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:27360 pid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5246 [inline] __schedule+0x107f/0x4030 kernel/sched/core.c:6563 schedule+0xb9/0x180 kernel/sched/core.c:6639 schedule_timeout+0x184/0x2d0 kernel/time/timer.c:2168 rcu_gp_fqs_loop+0x303/0x1350 kernel/rcu/tree.c:1706 rcu_gp_kthread+0x99/0x3b0 kernel/rcu/tree.c:1905 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 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: 4358 Comm: syz-executor379 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 RIP: 0010:preempt_count_add+0x5/0x190 kernel/sched/core.c:5702 Code: 00 80 e1 07 80 c1 03 38 c1 7c 8b 49 8d be 58 0d 00 00 e8 1e b2 7a 00 e9 7a ff ff ff e9 f9 fe ff ff 0f 1f 40 00 41 57 41 56 53 <49> bf 00 00 00 00 00 fc ff df 48 c7 c0 40 a1 c1 96 48 c1 e8 03 42 RSP: 0018:ffffc900042179a0 EFLAGS: 00000046 RAX: f3f3f3f8f1f1f1f1 RBX: ffff8880b8f2a5c0 RCX: ffff88802e2d0000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001 RBP: ffffc90004217a50 R08: ffffffff8e2116af R09: 1ffffffff1c422d5 R10: dffffc0000000000 R11: fffffbfff1c422d6 R12: dffffc0000000000 R13: ffff88807dd880e0 R14: 0000000000000802 R15: 1ffff92000842f38 FS: 0000555571974480(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000000058 CR3: 000000001ef53000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:109 [inline] _raw_spin_lock_irqsave+0x95/0x100 kernel/locking/spinlock.c:162 lock_hrtimer_base kernel/time/hrtimer.c:180 [inline] hrtimer_start_range_ns+0xec/0x1060 kernel/time/hrtimer.c:1347 posixtimer_rearm+0x12a/0x340 kernel/time/posix-timers.c:329 dequeue_signal+0x1ba/0x4a0 kernel/signal.c:704 get_signal+0x531/0x1340 kernel/signal.c:2760 arch_do_signal_or_restart+0xc4/0x1310 arch/x86/kernel/signal.c:871 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f5bc84708f4 Code: ff ff ff f0 83 88 08 03 00 00 10 64 48 8b 3c 25 00 03 00 00 e8 ad 15 00 00 66 66 2e 0f 1f 84 00 00 00 00 00 66 90 53 49 89 ca <64> 48 8b 1c 25 10 00 00 00 8b 83 08 03 00 00 80 3d ae a1 09 00 00 RSP: 002b:00007ffd56b191a0 EFLAGS: 00000206 RAX: ffffffffffffffff RBX: 000000000000000b RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000000000000a RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f5bc84d64c4 R13: 0000000000000047 R14: 00007ffd56b19220 R15: 0000000000000000