rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...!: (10065 ticks this GP) idle=0cf4/1/0x4000000000000000 softirq=127581/127582 fqs=4
rcu: 	(detected by 1, t=10503 jiffies, g=136225, q=792 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 19 Comm: migration/0 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Stopper: 0x0 <- 0x0
RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x70 kernel/kcov.c:210
Code: 66 03 5b 00 48 89 df 5b e9 fd 7d 60 00 be 03 00 00 00 5b e9 a2 1b ee 02 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <f3> 0f 1e fa 65 8b 05 05 73 05 12 48 8b 34 24 65 48 8b 15 e1 72 05
RSP: 0018:ffffc90000007698 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff8a51db7b
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88801e694980
RBP: ffff8880605ff2b0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0200000000000000 R12: ffff8880605ff334
R13: 0000000000000000 R14: ffff88806fa6b0d0 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff888124339000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000020000037f030 CR3: 00000000793b4000 CR4: 00000000003526f0
Call Trace:
 <IRQ>
 ipv6_masked_addr_cmp include/net/ipv6.h:516 [inline]
 ip6_packet_match net/ipv6/netfilter/ip6_tables.c:60 [inline]
 ip6t_do_table+0x54e/0x1c90 net/ipv6/netfilter/ip6_tables.c:306
 ip6t_mangle_out net/ipv6/netfilter/ip6table_mangle.c:49 [inline]
 ip6table_mangle_hook+0x31e/0x770 net/ipv6/netfilter/ip6table_mangle.c:72
 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline]
 nf_hook_slow+0xbf/0x220 net/netfilter/core.c:623
 nf_hook include/linux/netfilter.h:273 [inline]
 NF_HOOK include/linux/netfilter.h:316 [inline]
 ndisc_send_skb+0xb8a/0x1bf0 net/ipv6/ndisc.c:512
 ndisc_send_rs+0x129/0x680 net/ipv6/ndisc.c:722
 addrconf_rs_timer+0x424/0x880 net/ipv6/addrconf.c:4041
 call_timer_fn+0x19a/0x670 kernel/time/timer.c:1748
 expire_timers kernel/time/timer.c:1799 [inline]
 __run_timers+0x757/0xb30 kernel/time/timer.c:2373
 __run_timer_base kernel/time/timer.c:2385 [inline]
 __run_timer_base kernel/time/timer.c:2377 [inline]
 run_timer_base+0x114/0x190 kernel/time/timer.c:2394
 run_timer_softirq+0x1a/0x50 kernel/time/timer.c:2404
 handle_softirqs+0x1eb/0x9e0 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0xef/0x150 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+0xa3/0xc0 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:finish_task_switch.isra.0+0x20e/0xb80 kernel/sched/core.c:5155
Code: b2 03 0f 48 85 d2 0f 85 84 06 00 00 85 c0 0f 85 a7 01 00 00 48 89 df e8 20 e5 ff ff e8 2b a8 3a 00 fb 49 8d bc 24 80 16 00 00 <48> b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 0f b6 04 02 84
RSP: 0018:ffffc90000187c20 EFLAGS: 00000206
RAX: 00000000000031c3 RBX: ffff8880b843b1c0 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff8de7a76f RDI: ffff88801e696000
RBP: ffffc90000187c68 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: ffff88801e694980
R13: ffff88805e0ec980 R14: ffff888029c424c0 R15: ffff8880b843c000
 context_switch kernel/sched/core.c:5301 [inline]
 __schedule+0xff6/0x6120 kernel/sched/core.c:6911
 __schedule_loop kernel/sched/core.c:6993 [inline]
 schedule+0xdd/0x390 kernel/sched/core.c:7008
 smpboot_thread_fn+0x893/0xaa0 kernel/smpboot.c:156
 kthread+0x370/0x450 kernel/kthread.c:436
 ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
rcu: rcu_preempt kthread starved for 12785 jiffies! g136225 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1
yealink 6-1:36.0: urb_ctl_callback - urb status -71
rcu: 	Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
yealink 6-1:36.0: urb_irq_callback - urb status -71
rcu: RCU grace-period kthread stack dump:
yealink 6-1:36.0: unexpected response 0
task:rcu_preempt     state:R
yealink 6-1:36.0: urb_ctl_callback - urb status -71
  running task     stack:27832 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
yealink 6-1:36.0: urb_irq_callback - urb status -71
Call Trace:
yealink 6-1:36.0: unexpected response 0
 <TASK>
yealink 6-1:36.0: urb_ctl_callback - urb status -71
 context_switch kernel/sched/core.c:5298 [inline]
 __schedule+0xfee/0x6120 kernel/sched/core.c:6911
yealink 6-1:36.0: urb_irq_callback - urb status -71
yealink 6-1:36.0: unexpected response 0
yealink 6-1:36.0: urb_ctl_callback - urb status -71
yealink 6-1:36.0: urb_ctl_callback - urb status -71
yealink 6-1:36.0: urb_ctl_callback - urb status -71
 __schedule_loop kernel/sched/core.c:6993 [inline]
 schedule+0xdd/0x390 kernel/sched/core.c:7008
yealink 6-1:36.0: urb_ctl_callback - urb status -71
 schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99
yealink 6-1:36.0: urb_irq_callback - urb status -71
yealink 6-1:36.0: unexpected response 0
yealink 6-1:36.0: urb_ctl_callback - urb status -71
yealink 6-1:36.0: urb_irq_callback - urb status -71
yealink 6-1:36.0: unexpected response 0
 rcu_gp_fqs_loop+0x1a9/0x900 kernel/rcu/tree.c:2095
yealink 6-1:36.0: urb_ctl_callback - urb status -71
yealink 6-1:36.0: urb_irq_callback - urb status -71
yealink 6-1:36.0: unexpected response 0
 rcu_gp_kthread+0x179/0x230 kernel/rcu/tree.c:2297
 kthread+0x370/0x450 kernel/kthread.c:436
 ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158
yealink 6-1:36.0: urb_ctl_callback - urb status -71
yealink 6-1:36.0: urb_ctl_callback - usb_submit_urb failed -19
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:63
Code: a8 81 02 c3 cc cc cc cc 0f 1f 00 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 a3 51 1a 00 fb f4 <e9> fc 35 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0018:ffffc90000197df0 EFLAGS: 00000246
RAX: 0000000006a98a33 RBX: ffff88801e6924c0 RCX: ffffffff8b913c75
RDX: 0000000000000000 RSI: ffffffff8de7a76f RDI: ffffffff8c1b1e20
RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed10170a679d
R10: ffff8880b8533ceb R11: 0000000000000000 R12: 0000000000000001
R13: ffffed1003cd2498 R14: 0000000000000001 R15: ffffffff90d9d210
FS:  0000000000000000(0000) GS:ffff888124439000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055557db514e8 CR3: 0000000032ec1000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000080083
DR3: ffffffffefffff16 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 arch_safe_halt arch/x86/include/asm/paravirt.h:73 [inline]
 default_idle+0x9/0x10 arch/x86/kernel/process.c:767
 default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122
 cpuidle_idle_call kernel/sched/idle.c:199 [inline]
 do_idle+0x464/0x590 kernel/sched/idle.c:352
 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:451
 start_secondary+0x21d/0x2d0 arch/x86/kernel/smpboot.c:312
 common_startup_64+0x13e/0x148
 </TASK>
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 19105 Comm: syz.6.3258 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
RIP: 0010:rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline]
RIP: 0010:rcu_is_watching+0x12/0xc0 kernel/rcu/tree.c:752
Code: 00 e9 49 ff ff ff 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 55 53 65 ff 05 73 f3 20 12 e8 1e c8 a3 09 <48> c7 c3 e8 ac 0f 94 89 c5 83 f8 07 0f 87 82 00 00 00 48 8d 3c ed
RSP: 0018:ffffc90006e27650 EFLAGS: 00000296
RAX: 0000000000000000 RBX: ffffc90006e27958 RCX: ffffffff91883201
RDX: ffffc90006e27960 RSI: ffffffff8c1b1da0 RDI: ffffffff8c1b1de0
RBP: 0000000000000001 R08: 0000000000000001 R09: 0000000000000007
R10: 0000000000000200 R11: 00000000000180b6 R12: ffffc90006e27728
R13: ffffc90006e276d8 R14: ffffc90006e27958 R15: ffffc90006e2770c
FS:  0000000000000000(0000) GS:ffff888124339000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005582e2b23a78 CR3: 00000000258b7000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 rcu_read_unlock include/linux/rcupdate.h:879 [inline]
 class_rcu_destructor include/linux/rcupdate.h:1193 [inline]
 unwind_next_frame+0x745/0x1ea0 arch/x86/kernel/unwind_orc.c:495
 arch_stack_walk+0x94/0xf0 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
 save_stack+0x162/0x1e0 mm/page_owner.c:165
 __reset_page_owner+0x84/0x190 mm/page_owner.c:320
 reset_page_owner include/linux/page_owner.h:25 [inline]
 __free_pages_prepare mm/page_alloc.c:1433 [inline]
 __free_frozen_pages+0x7e1/0x10d0 mm/page_alloc.c:2978
 vfree.part.0+0x12b/0x9d0 mm/vmalloc.c:3479
 vfree+0x55/0x80 mm/vmalloc.c:3456
 kcov_put kernel/kcov.c:442 [inline]
 kcov_put kernel/kcov.c:438 [inline]
 kcov_close+0x34/0x60 kernel/kcov.c:543
 __fput+0x3ff/0xb40 fs/file_table.c:469
 task_work_run+0x150/0x240 kernel/task_work.c:233
 exit_task_work include/linux/task_work.h:40 [inline]
 do_exit+0x8b8/0x2b60 kernel/exit.c:976
 do_group_exit+0xd5/0x2a0 kernel/exit.c:1118
 get_signal+0x1ec7/0x21e0 kernel/signal.c:3034
 arch_do_signal_or_restart+0x91/0x7a0 arch/x86/kernel/signal.c:337
 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline]
 exit_to_user_mode_loop+0x86/0x4a0 kernel/entry/common.c:98
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline]
 do_syscall_64+0x67c/0xf80 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f33f935d04e
Code: Unable to access opcode bytes at 0x7f33f935d024.
RSP: 002b:00007f33fa247f58 EFLAGS: 00000246 ORIG_RAX: 00000000000000e6
RAX: fffffffffffffdfc RBX: 00007f33fa2486c0 RCX: 00007f33f935d04e
RDX: 00007f33fa247fb0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f33f9432c91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f33f9616038 R14: 00007f33f9615fa0 R15: 00007ffd5426ec88
 </TASK>