rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P788/1:b..l rcu: (detected by 1, t=10502 jiffies, g=41745, q=73 ncpus=2) task:kworker/1:2 state:R running task stack:24328 pid:788 ppid:2 flags:0x00004000 Workqueue: events_power_efficient gc_worker Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x1553/0x45a0 kernel/sched/core.c:6700 preempt_schedule_irq+0xbf/0x150 kernel/sched/core.c:7010 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_acquire+0x208/0x420 kernel/locking/lockdep.c:5758 Code: f7 84 24 80 00 00 00 00 02 00 00 43 c6 44 3c 04 f8 0f 85 f0 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 04 3c 00 00 00 00 43 c7 44 3c 08 00 00 00 00 65 48 8b 04 25 RSP: 0000:ffffc90003fd7940 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 0000000000000000 RCX: 38710f0fcb937b00 RDX: 0000000000000000 RSI: ffffffff8acada80 RDI: ffffffff8b1c80e0 RBP: ffffc90003fd7a48 R08: dffffc0000000000 R09: 1ffffffff2237ca0 R10: dffffc0000000000 R11: fffffbfff2237ca1 R12: 1ffff920007faf34 R13: ffffffff8d131fe0 R14: 0000000000000246 R15: dffffc0000000000 rcu_lock_acquire include/linux/rcupdate.h:334 [inline] rcu_read_lock include/linux/rcupdate.h:786 [inline] gc_worker+0x28d/0x1490 net/netfilter/nf_conntrack_core.c:1502 process_one_work kernel/workqueue.c:2634 [inline] process_scheduled_works+0xa5d/0x15d0 kernel/workqueue.c:2711 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792 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: rcu_preempt kthread starved for 10514 jiffies! g41745 f0x0 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:27656 pid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x1553/0x45a0 kernel/sched/core.c:6700 schedule+0xbd/0x170 kernel/sched/core.c:6774 schedule_timeout+0x188/0x2d0 kernel/time/timer.c:2168 rcu_gp_fqs_loop+0x313/0x1590 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: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 10045 Comm: syz.3.1225 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:get_current arch/x86/include/asm/current.h:41 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x8/0x60 kernel/kcov.c:215 Code: 00 00 f3 0f 1e fa 53 48 89 fb e8 13 00 00 00 48 8b 3d fc c8 03 0d 48 89 de 5b e9 93 57 57 00 cc cc cc f3 0f 1e fa 48 8b 04 24 <65> 48 8b 0d 90 a2 7c 7e 65 8b 15 91 a2 7c 7e 81 e2 00 01 ff 00 74 RSP: 0000:ffffc900056ff148 EFLAGS: 00000046 RAX: ffffffff8a7369b3 RBX: ffff8880b8e3c930 RCX: dffffc0000000000 RDX: ffffc9000db1d000 RSI: 000000000007ffff RDI: 0000000000080000 RBP: ffff8880b8e3c930 R08: ffff8880b8e3c95b R09: 1ffff110171c792b R10: dffffc0000000000 R11: ffffed10171c792c R12: ffff88807c3d8500 R13: dffffc0000000000 R14: ffff88801e2c0518 R15: ffff88801e2c0520 FS: 00007f63d52936c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000000058 CR3: 000000004aa4d000 CR4: 00000000003506f0 Call Trace: plist_check_prev_next lib/plist.c:35 [inline] plist_check_list+0xe3/0x240 lib/plist.c:48 plist_check_head lib/plist.c:60 [inline] plist_add+0x66/0x490 lib/plist.c:78 enqueue_pushable_task kernel/sched/rt.c:440 [inline] put_prev_task_rt+0x24a/0x400 kernel/sched/rt.c:1836 put_prev_task kernel/sched/sched.h:2313 [inline] put_prev_task_balance kernel/sched/core.c:5985 [inline] pick_next_task kernel/sched/core.c:6120 [inline] __schedule+0x27f5/0x45a0 kernel/sched/core.c:6662 preempt_schedule_common+0x82/0xc0 kernel/sched/core.c:6867 preempt_schedule+0xc0/0xd0 kernel/sched/core.c:6891 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk_64.S:45 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] _raw_spin_unlock_irqrestore+0x111/0x120 kernel/locking/spinlock.c:194 spin_unlock_irqrestore include/linux/spinlock.h:406 [inline] __wake_up_common_lock kernel/sched/wait.c:140 [inline] __wake_up_sync_key+0x12c/0x1a0 kernel/sched/wait.c:213 __unix_dgram_recvmsg+0x4b8/0xd80 net/unix/af_unix.c:2437 sock_recvmsg_nosec+0x82/0xd0 net/socket.c:1046 ____sys_recvmsg+0x4e8/0x5e0 net/socket.c:2811 ___sys_recvmsg+0x216/0x590 net/socket.c:2855 do_recvmmsg+0x39a/0x870 net/socket.c:2949 __sys_recvmmsg net/socket.c:3028 [inline] __do_sys_recvmmsg net/socket.c:3051 [inline] __se_sys_recvmmsg net/socket.c:3044 [inline] __x64_sys_recvmmsg+0x199/0x250 net/socket.c:3044 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f63d439acb9 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f63d5293028 EFLAGS: 00000246 ORIG_RAX: 000000000000012b RAX: ffffffffffffffda RBX: 00007f63d4616090 RCX: 00007f63d439acb9 RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000003 RBP: 00007f63d4408bf7 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f63d4616128 R14: 00007f63d4616090 R15: 00007ffe37bb9a18