rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: (detected by 0, t=10502 jiffies, g=15213, q=116 ncpus=2) rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4294964984-4294954482), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 10502 jiffies! g15213 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:25784 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: <TASK> context_switch kernel/sched/core.c:5369 [inline] __schedule+0x17fb/0x4be0 kernel/sched/core.c:6756 __schedule_loop kernel/sched/core.c:6833 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6848 schedule_timeout+0x15a/0x290 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2045 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2247 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 </TASK> rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 7294 Comm: syz.3.428 Not tainted 6.13.0-rc6-syzkaller-00262-gb62cef9a5c67 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:lookup_chain_cache_add kernel/locking/lockdep.c:3817 [inline] RIP: 0010:validate_chain+0x1cb/0x5920 kernel/locking/lockdep.c:3872 Code: 8d 1c c5 c0 17 de 93 48 89 d8 48 c1 e8 03 48 89 44 24 68 42 80 3c 20 00 74 08 48 89 df e8 3d e1 87 00 48 89 5c 24 48 48 8b 1b <48> 85 db 74 48 48 83 c3 f8 74 42 4c 8d 7b 18 4c 89 f8 48 c1 e8 03 RSP: 0018:ffffc90000a18700 EFLAGS: 00000046 RAX: 1ffffffff27f0f22 RBX: ffffffff943c79a8 RCX: ffffffff817b689e RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff942719f8 RBP: ffffc90000a18a00 R08: ffffffff942719ff R09: 1ffffffff284e33f R10: dffffc0000000000 R11: fffffbfff284e340 R12: dffffc0000000000 R13: ffff888078fd0b00 R14: a0f3841ad0514bb5 R15: 0000000000000001 FS: 00007fe95b2e06c0(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020001c40 CR3: 0000000030c00000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <NMI> </NMI> <IRQ> __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5226 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:351 [inline] advance_sched+0xab/0xca0 net/sched/sch_taprio.c:924 __run_hrtimer kernel/time/hrtimer.c:1739 [inline] __hrtimer_run_queues+0x59b/0xd30 kernel/time/hrtimer.c:1803 hrtimer_interrupt+0x403/0xa40 kernel/time/hrtimer.c:1865 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline] __sysvec_apic_timer_interrupt+0x110/0x420 arch/x86/kernel/apic/apic.c:1055 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1049 </IRQ> <TASK> asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:finish_task_switch+0x1ea/0x870 kernel/sched/core.c:5243 Code: c9 50 e8 49 0c 0c 00 48 83 c4 08 4c 89 f7 e8 ed 39 00 00 e9 de 04 00 00 4c 89 f7 e8 30 19 55 0a e8 6b 89 38 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:ffffc90003427788 EFLAGS: 00000282 RAX: 4568dac0476b5700 RBX: ffff888078fd0000 RCX: ffffffff9a378903 RDX: dffffc0000000000 RSI: ffffffff8c0a98e0 RDI: ffffffff8c5edd60 RBP: ffffc900034277d0 R08: ffffffff90185877 R09: 1ffffffff2030b0e R10: dffffc0000000000 R11: fffffbfff2030b0f R12: 1ffff110170e7eac R13: dffffc0000000000 R14: ffff8880b863e740 R15: ffff8880b873f560 context_switch kernel/sched/core.c:5372 [inline] __schedule+0x1803/0x4be0 kernel/sched/core.c:6756 __schedule_loop kernel/sched/core.c:6833 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6848 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: 0033:0x7fe95a585d29 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:00007fe95b2e00e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: ffffffffffffffda RBX: 00007fe95a775fa8 RCX: 00007fe95a585d29 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fe95a775fa8 RBP: 00007fe95a775fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fe95a775fac R13: 0000000000000000 R14: 00007ffdd6caf030 R15: 00007ffdd6caf118 </TASK>