rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-...!: (1 GPs behind) idle=e0d4/1/0x4000000000000000 softirq=177890/177891 fqs=1
rcu: 	(t=10500 jiffies g=173281 q=21 ncpus=2)
rcu: rcu_preempt kthread timer wakeup didn't happen for 10497 jiffies! g173281 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=0 timer-softirq=97728
rcu: rcu_preempt kthread starved for 10498 jiffies! g173281 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:27568 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5256 [inline]
 __schedule+0x14bc/0x5000 kernel/sched/core.c:6863
 __schedule_loop kernel/sched/core.c:6945 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6960
 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+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 23169 Comm: syz.0.4417 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82
Code: 13 ee 02 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d f3 10 0d 00 f3 0f 1e fa fb f4 <c3> cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc90004a16d58 EFLAGS: 000002c7
RAX: ffffffff8173727d RBX: 0000000000000003 RCX: 0000000000080000
RDX: ffffc9001190d000 RSI: 000000000000aaa9 RDI: 000000000000aaaa
RBP: ffffc90004a16e30 R08: ffffffff8f81fa77 R09: 1ffffffff1f03f4e
R10: dffffc0000000000 R11: fffffbfff1f03f4f R12: dffffc0000000000
R13: 0000000000000200 R14: 0000000000000003 R15: 1ffff92000942db0
FS:  00007efd01db46c0(0000) GS:ffff888125e3a000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007efd01db3f98 CR3: 00000000626e4000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
 kvm_wait+0x232/0x290 arch/x86/kernel/kvm.c:1085
 pv_wait arch/x86/include/asm/paravirt.h:569 [inline]
 pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:466 [inline]
 __pv_queued_spin_lock_slowpath+0x7bf/0xb60 kernel/locking/qspinlock.c:325
 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:557 [inline]
 queued_spin_lock_slowpath+0x43/0x50 arch/x86/include/asm/qspinlock.h:51
 queued_spin_lock include/asm-generic/qspinlock.h:114 [inline]
 do_raw_spin_lock+0x21f/0x290 kernel/locking/spinlock_debug.c:116
 netem_change+0x478/0x28c0 net/sched/sch_netem.c:1042
 netem_init+0x65/0xc0 net/sched/sch_netem.c:1141
 qdisc_create+0x7ac/0xea0 net/sched/sch_api.c:1319
 __tc_modify_qdisc net/sched/sch_api.c:1753 [inline]
 tc_modify_qdisc+0x1547/0x2020 net/sched/sch_api.c:1817
 rtnetlink_rcv_msg+0x77c/0xb70 net/core/rtnetlink.c:6967
 netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2550
 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
 netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1344
 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1894
 sock_sendmsg_nosec net/socket.c:727 [inline]
 __sock_sendmsg+0x21c/0x270 net/socket.c:742
 ____sys_sendmsg+0x505/0x820 net/socket.c:2592
 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2646
 __sys_sendmsg net/socket.c:2678 [inline]
 __do_sys_sendmsg net/socket.c:2683 [inline]
 __se_sys_sendmsg net/socket.c:2681 [inline]
 __x64_sys_sendmsg+0x19b/0x260 net/socket.c:2681
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7efd03b8f749
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:00007efd01db4038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007efd03de6180 RCX: 00007efd03b8f749
RDX: 0000000020000804 RSI: 0000200000000080 RDI: 0000000000000008
RBP: 00007efd03c13f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007efd03de6218 R14: 00007efd03de6180 R15: 00007efd03f0fa28
 </TASK>
CPU: 1 UID: 0 PID: 23163 Comm: syz.5.4419 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:check_kcov_mode kernel/kcov.c:183 [inline]
RIP: 0010:write_comp_data kernel/kcov.c:246 [inline]
RIP: 0010:__sanitizer_cov_trace_const_cmp2+0x28/0x90 kernel/kcov.c:307
Code: 90 90 f3 0f 1e fa 48 8b 04 24 65 48 8b 14 25 08 60 7e 92 65 8b 0d c8 ab bc 10 81 e1 00 01 ff 00 74 11 81 f9 00 01 00 00 75 5b <83> ba 6c 16 00 00 00 74 52 8b 8a 48 16 00 00 83 f9 03 75 47 48 8b
RSP: 0018:ffffc90000a084c8 EFLAGS: 00000246
RAX: ffffffff895c8ef6 RBX: 0000000000000008 RCX: 0000000000000100
RDX: ffff88809df53d00 RSI: 0000000000000008 RDI: 0000000000000300
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000004
R10: 0000000000000008 R11: 0000000000000100 R12: ffff88801d7006dc
R13: ffff8880567be200 R14: dffffc0000000000 R15: 0000000000000000
FS:  00007f4e4526f6c0(0000) GS:ffff888125f3a000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fbb8c372a60 CR3: 00000000625f2000 CR4: 00000000003526f0
Call Trace:
 <IRQ>
 tcf_classify+0x486/0x1140 net/sched/cls_api.c:-1
 hfsc_classify net/sched/sch_hfsc.c:1146 [inline]
 hfsc_enqueue+0x323/0xf20 net/sched/sch_hfsc.c:1545
 dev_qdisc_enqueue+0x4e/0x240 net/core/dev.c:4134
 __dev_xmit_skb net/core/dev.c:4247 [inline]
 __dev_queue_xmit+0x1829/0x3140 net/core/dev.c:4783
 neigh_output include/net/neighbour.h:556 [inline]
 ip_finish_output2+0xd40/0x1160 net/ipv4/ip_output.c:237
 NF_HOOK_COND include/linux/netfilter.h:307 [inline]
 ip_output+0x29f/0x450 net/ipv4/ip_output.c:438
 igmpv3_send_cr net/ipv4/igmp.c:726 [inline]
 igmp_ifc_timer_expire+0xbb6/0xde0 net/ipv4/igmp.c:816
 call_timer_fn+0x16e/0x590 kernel/time/timer.c:1748
 expire_timers kernel/time/timer.c:1799 [inline]
 __run_timers kernel/time/timer.c:2373 [inline]
 __run_timer_base+0x61a/0x860 kernel/time/timer.c:2385
 run_timer_base kernel/time/timer.c:2394 [inline]
 run_timer_softirq+0xb7/0x180 kernel/time/timer.c:2404
 handle_softirqs+0x27d/0x850 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:723
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
 sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1056
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:bytes_is_nonzero mm/kasan/generic.c:97 [inline]
RIP: 0010:memory_is_nonzero mm/kasan/generic.c:115 [inline]
RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:140 [inline]
RIP: 0010:memory_is_poisoned mm/kasan/generic.c:172 [inline]
RIP: 0010:check_region_inline mm/kasan/generic.c:191 [inline]
RIP: 0010:kasan_check_range+0xa8/0x2c0 mm/kasan/generic.c:200
Code: 89 f4 4d 29 dc 49 83 fc 10 7f 29 4d 85 e4 0f 84 41 01 00 00 4c 89 cb 48 f7 d3 4c 01 fb 41 80 3b 00 0f 85 de 01 00 00 49 ff c3 <48> ff c3 75 ee e9 21 01 00 00 44 89 dd 83 e5 07 0f 84 b5 00 00 00
RSP: 0018:ffffc900033d74c0 EFLAGS: 00000282
RAX: 1ffff9200067ae01 RBX: fffffffffffffffe RCX: ffffffff81744b78
RDX: 0000000000000001 RSI: 0000000000000010 RDI: ffffc900033d7638
RBP: 0000000000000000 R08: ffffc900033d7647 R09: 1ffff9200067aec8
R10: dffffc0000000000 R11: fffff5200067aec8 R12: 0000000000000002
R13: ffffc900033d7638 R14: fffff5200067aec9 R15: 1ffff9200067aec7
 __asan_memset+0x22/0x50 mm/kasan/shadow.c:84
 unwind_next_frame+0xc98/0x2390 arch/x86/kernel/unwind_orc.c:592
 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:56 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:77
 unpoison_slab_object mm/kasan/common.c:339 [inline]
 __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:365
 kasan_slab_alloc include/linux/kasan.h:252 [inline]
 slab_post_alloc_hook mm/slub.c:4953 [inline]
 slab_alloc_node mm/slub.c:5263 [inline]
 kmem_cache_alloc_noprof+0x37d/0x710 mm/slub.c:5270
 getname_flags+0xb8/0x540 fs/namei.c:146
 getname include/linux/fs.h:2498 [inline]
 io_renameat_prep+0x211/0x3d0 io_uring/fs.c:70
 io_init_req io_uring/io_uring.c:2234 [inline]
 io_submit_sqe io_uring/io_uring.c:2281 [inline]
 io_submit_sqes+0xad3/0x2140 io_uring/io_uring.c:2434
 __do_sys_io_uring_enter io_uring/io_uring.c:3280 [inline]
 __se_sys_io_uring_enter+0x2e0/0x2b60 io_uring/io_uring.c:3219
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4e4438f749
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:00007f4e4526f038 EFLAGS: 00000246 ORIG_RAX: 00000000000001aa
RAX: ffffffffffffffda RBX: 00007f4e445e5fa0 RCX: 00007f4e4438f749
RDX: 0000000000003e80 RSI: 00000000000047ba RDI: 0000000000000007
RBP: 00007f4e44413f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f4e445e6038 R14: 00007f4e445e5fa0 R15: 00007f4e4470fa28
 </TASK>
sched: DL replenish lagged too much