rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: (detected by 0, t=10502 jiffies, g=9045, q=84 ncpus=2) rcu: All QSes seen, last rcu_preempt kthread activity 10503 (4294955773-4294945270), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 10504 jiffies! g9045 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:27152 pid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x15ae/0x4660 kernel/sched/core.c:6701 preempt_schedule_irq+0xbf/0x150 kernel/sched/core.c:7011 irqentry_exit+0x67/0x70 kernel/entry/common.c:438 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0010:lock_timer_base+0x1d/0x270 kernel/time/timer.c:-1 Code: 1e 69 00 e9 3c fd ff ff 0f 1f 44 00 00 55 41 57 41 56 41 55 41 54 53 48 83 ec 10 48 89 f3 49 89 fe e8 27 a1 10 00 49 83 c6 20 <4c> 89 34 24 49 c1 ee 03 48 89 d8 48 c1 e8 03 48 89 44 24 08 eb 07 RSP: 0018:ffffc90000167a08 EFLAGS: 00000286 RAX: ffffffff8176cdf9 RBX: ffffc90000167a58 RCX: ffff88801b670000 RDX: 0000000000000000 RSI: ffffc90000167a58 RDI: ffffc90000167ba0 RBP: 0000000000000000 R08: ffffffff8e8c7caf R09: 1ffffffff1d18f95 R10: dffffc0000000000 R11: fffffbfff1d18f96 R12: dffffc0000000000 R13: 1ffff9200002cf58 R14: ffffc90000167bc0 R15: 0000000000000000 __try_to_del_timer_sync+0x55/0x280 kernel/time/timer.c:1414 __timer_delete_sync+0x223/0x2e0 kernel/time/timer.c:1574 timer_delete_sync kernel/time/timer.c:1629 [inline] del_timer_sync include/linux/timer.h:200 [inline] schedule_timeout+0x192/0x2d0 kernel/time/timer.c:2169 rcu_gp_fqs_loop+0x30d/0x1590 kernel/rcu/tree.c:1667 rcu_gp_kthread+0x9d/0x3b0 kernel/rcu/tree.c:1866 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: 0 PID: 5780 Comm: syz-executor862 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline] RIP: 0010:_raw_spin_unlock_irq+0x29/0x50 kernel/locking/spinlock.c:202 Code: 00 f3 0f 1e fa 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 da 8c d2 f6 48 89 df e8 82 60 d3 f6 e8 ad 61 f7 f6 fb bf 01 00 00 00 b2 6e c6 f6 65 8b 05 13 3d 6d 75 85 c0 74 02 5b c3 e8 c0 21 6a RSP: 0018:ffffc9000450fd20 EFLAGS: 00000282 RAX: 162b003cf56bd100 RBX: ffff88802ed73780 RCX: 162b003cf56bd100 RDX: dffffc0000000000 RSI: ffffffff8acacbe0 RDI: 0000000000000001 RBP: 0000000000000000 R08: ffffffff8e8c7caf R09: 1ffffffff1d18f95 R10: dffffc0000000000 R11: fffffbfff1d18f96 R12: 0000000000000000 R13: 0000000100000000 R14: ffff88802ff63c00 R15: 0000000000000020 FS: 00007f79cdf496c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000000058 CR3: 0000000071c1a000 CR4: 00000000003506f0 Call Trace: set_current_blocked kernel/signal.c:3086 [inline] signal_delivered kernel/signal.c:2947 [inline] signal_setup_done+0x189/0x310 kernel/signal.c:2959 handle_signal arch/x86/kernel/signal.c:285 [inline] arch_do_signal_or_restart+0x4bd/0x7b0 arch/x86/kernel/signal.c:312 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:291 [inline] syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302 do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f79cdf7d150 Code: 83 c0 16 83 e0 f7 74 12 50 48 8d 3d 6a a4 06 00 e8 85 ae fd ff 0f 1f 44 00 00 c3 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 <83> ff 21 74 0b c3 66 2e 0f 1f 84 00 00 00 00 00 55 53 48 89 f3 48 RSP: 002b:00007f79cdf48bb8 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 00007f79ce019b28 RCX: 00007f79cdf6a4d9 RDX: 00007f79cdf48bc0 RSI: 00007f79cdf48cf0 RDI: 0000000000000021 RBP: 00007f79ce019b20 R08: 00007f79cdf49cdc R09: 00007f79cdf49cdc R10: 0000000000000000 R11: 0000000000000246 R12: 00007f79ce019b2c R13: 0000000000000000 R14: 00007ffdc17a4c20 R15: 00007ffdc17a4d08