rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: (detected by 1, t=10502 jiffies, g=22533, q=404 ncpus=2) rcu: All QSes seen, last rcu_preempt kthread activity 10503 (4294969784-4294959281), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 10504 jiffies! g22533 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:25936 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5408 [inline] __schedule+0x1796/0x49d0 kernel/sched/core.c:6745 __schedule_loop kernel/sched/core.c:6822 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6837 schedule_timeout+0x1be/0x310 kernel/time/timer.c:2581 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2000 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2202 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 rcu: Stack dump where RCU GP kthread last ran: CPU: 1 PID: 7396 Comm: syz-executor.4 Not tainted 6.10.0-rc3-syzkaller-00044-g2ccbdf43d5e7 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024 RIP: 0010:finish_task_switch+0x1ea/0x870 kernel/sched/core.c:5282 Code: c9 50 e8 99 c9 0b 00 48 83 c4 08 4c 89 f7 e8 cd 38 00 00 0f 1f 44 00 00 4c 89 f7 e8 50 23 22 0a e8 6b f8 36 00 fb 48 8b 5d c0 <48> 8d bb f8 15 00 00 48 89 f8 48 c1 e8 03 49 be 00 00 00 00 00 fc RSP: 0018:ffffc90004c0f628 EFLAGS: 00000282 RAX: c81f10f659eb0300 RBX: ffff88807fb09e00 RCX: ffffffff9476c603 RDX: dffffc0000000000 RSI: ffffffff8bcabb80 RDI: ffffffff8c1f2480 RBP: ffffc90004c0f670 R08: ffffffff8fac246f R09: 1ffffffff1f5848d R10: dffffc0000000000 R11: fffffbfff1f5848e R12: 1ffff110172a7e9f R13: dffffc0000000000 R14: ffff8880b953e780 R15: ffff8880b953f4f8 FS: 00007f1787fb36c0(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fc00e746f00 CR3: 0000000062732000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: context_switch kernel/sched/core.c:5411 [inline] __schedule+0x179e/0x49d0 kernel/sched/core.c:6745 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:7067 irqentry_exit+0x5e/0x90 kernel/entry/common.c:354 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:preempt_count_add+0x6/0x190 kernel/sched/core.c:5860 Code: 48 8b 3c 24 e8 3b 08 93 00 eb 8c e9 ee fe ff ff 0f 1f 40 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 41 57 <41> 56 53 89 fb 48 c7 c0 e0 c6 76 94 48 c1 e8 03 49 bf 00 00 00 00 RSP: 0018:ffffc90004c0f9f0 EFLAGS: 00000202 RAX: 0000000000000001 RBX: 1ffff1100ff613c0 RCX: 0000000000000001 RDX: dffffc0000000000 RSI: ffffffff8bcabb80 RDI: 0000000000000001 RBP: ffff88807fb09e00 R08: ffffffff8fac246f R09: 1ffffffff1f5848d R10: dffffc0000000000 R11: fffffbfff1f5848e R12: dffffc0000000000 R13: ffffc90004c0faf8 R14: ffffffff8b872520 R15: ffff88807fb0b078 __schedule_loop kernel/sched/core.c:6821 [inline] schedule+0x144/0x320 kernel/sched/core.c:6837 futex_wait_queue+0x14e/0x1d0 kernel/futex/waitwake.c:370 __futex_wait+0x17f/0x320 kernel/futex/waitwake.c:669 futex_wait+0x101/0x360 kernel/futex/waitwake.c:697 do_futex+0x33b/0x560 kernel/futex/syscalls.c:102 __do_sys_futex kernel/futex/syscalls.c:179 [inline] __se_sys_futex+0x3f9/0x480 kernel/futex/syscalls.c:160 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f178727cea9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 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:00007f1787fb3178 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: ffffffffffffffda RBX: 00007f17873b4058 RCX: 00007f178727cea9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f17873b4058 RBP: 00007f17873b4050 R08: 00007f1787fb36c0 R09: 00007f1787fb36c0 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f17873b405c R13: 000000000000006e R14: 00007fffdc573bb0 R15: 00007fffdc573c98