rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: (detected by 0, t=10504 jiffies, g=16817, q=464 ncpus=2) rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4294961353-4294950851), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 10502 jiffies! g16817 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:27656 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0x165/0x360 kernel/sched/core.c:7058 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 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: 6504 Comm: syz.0.16 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:kasan_mem_to_shadow include/linux/kasan.h:64 [inline] RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:129 [inline] RIP: 0010:memory_is_poisoned mm/kasan/generic.c:161 [inline] RIP: 0010:check_region_inline mm/kasan/generic.c:180 [inline] RIP: 0010:kasan_check_range+0x53/0x2c0 mm/kasan/generic.c:189 Code: 00 00 00 00 80 ff ff eb 11 cc cc cc f3 0f 1e fa 49 b9 00 00 00 00 00 00 00 ff f3 0f 1e fa 4c 39 cf 0f 82 58 02 00 00 49 89 ff <49> c1 ef 03 49 ba 00 00 00 00 00 fc ff df 4f 8d 1c 17 49 ff c8 4d RSP: 0018:ffffc90000a08bf0 EFLAGS: 00000006 RAX: 0000000000000001 RBX: ffff888033bd32e8 RCX: ffffffff819e033d RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff888033bd32e8 RBP: ffff88802f959550 R08: ffff888033bd32ec R09: ffff800000000000 R10: dffffc0000000000 R11: ffffed1005f2b291 R12: dffffc0000000000 R13: ffff888033bd3000 R14: ffff888033bd32ec R15: ffff888033bd32e8 FS: 00007f96509e16c0(0000) GS:ffff888125d1b000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f974d311286 CR3: 000000005b3b2000 CR4: 00000000003526f0 Call Trace: instrument_atomic_read include/linux/instrumented.h:68 [inline] atomic_read include/linux/atomic/atomic-instrumented.h:32 [inline] queued_spin_is_locked include/asm-generic/qspinlock.h:57 [inline] debug_spin_unlock kernel/locking/spinlock_debug.c:101 [inline] do_raw_spin_unlock+0x4d/0x240 kernel/locking/spinlock_debug.c:141 __raw_spin_unlock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_unlock+0x1e/0x50 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:391 [inline] advance_sched+0x99f/0xc90 net/sched/sch_taprio.c:986 __run_hrtimer kernel/time/hrtimer.c:1761 [inline] __hrtimer_run_queues+0x52c/0xc60 kernel/time/hrtimer.c:1825 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1887 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1039 [inline] __sysvec_apic_timer_interrupt+0x108/0x410 arch/x86/kernel/apic/apic.c:1056 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0xa8/0x110 kernel/locking/spinlock.c:194 Code: 74 05 e8 1b 17 4b f6 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f6 44 24 21 02 75 4f f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 43 bf 13 f6 65 8b 05 0c 12 24 07 85 c0 74 40 48 c7 04 24 0e 36 RSP: 0018:ffffc90003b5edc0 EFLAGS: 00000206 RAX: 1918c4e1d68a2b00 RBX: 0000000000000a06 RCX: 1918c4e1d68a2b00 RDX: 0000000000000006 RSI: ffffffff8d9b735f RDI: 0000000000000001 RBP: ffffc90003b5ee50 R08: ffffffff8fa38637 R09: 1ffffffff1f470c6 R10: dffffc0000000000 R11: fffffbfff1f470c7 R12: dffffc0000000000 R13: 0000000000000a06 R14: ffff88814043b108 R15: 1ffff9200076bdb8 kthread_queue_work+0x111/0x180 kernel/kthread.c:1195 synchronize_rcu_expedited_queue_work kernel/rcu/tree_exp.h:498 [inline] synchronize_rcu_expedited+0x4b5/0x730 kernel/rcu/tree_exp.h:967 lockdep_unregister_key+0x29b/0x310 kernel/locking/lockdep.c:6628 __qdisc_destroy+0x166/0x420 net/sched/sch_generic.c:1083 taprio_attach+0x25a/0x380 net/sched/sch_taprio.c:2160 qdisc_graft+0x1172/0x1590 net/sched/sch_api.c:1162 __tc_modify_qdisc net/sched/sch_api.c:1756 [inline] tc_modify_qdisc+0x189b/0x20e0 net/sched/sch_api.c:1812 rtnetlink_rcv_msg+0x77c/0xb70 net/core/rtnetlink.c:6955 netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2552 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline] netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1346 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1896 sock_sendmsg_nosec net/socket.c:714 [inline] __sock_sendmsg+0x21c/0x270 net/socket.c:729 ____sys_sendmsg+0x505/0x830 net/socket.c:2614 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2668 __sys_sendmsg net/socket.c:2700 [inline] __do_sys_sendmsg net/socket.c:2705 [inline] __se_sys_sendmsg net/socket.c:2703 [inline] __x64_sys_sendmsg+0x19b/0x260 net/socket.c:2703 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f964fb8e969 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:00007f96509e1038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f964fdb5fa0 RCX: 00007f964fb8e969 RDX: 0000000000000000 RSI: 00002000000007c0 RDI: 0000000000000003 RBP: 00007f964fc10ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f964fdb5fa0 R15: 00007f964fedfa28