syzbot

IPVS: wlc: UDP 224.0.0.2:0 - no destination available
IPVS: wlc: UDP 224.0.0.2:0 - no destination available
IPVS: wlc: UDP 224.0.0.2:0 - no destination available
IPVS: wlc: UDP 224.0.0.2:0 - no destination available
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	1-...!: (1 GPs behind) idle=10d4/1/0x4000000000000000 softirq=72835/72836 fqs=0
rcu: 	(detected by 0, t=10502 jiffies, g=87817, q=665 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 13535 Comm: syz.3.1858 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:taprio_set_budgets+0x251/0x310 net/sched/sch_taprio.c:680
Code: 30 01 00 00 4c 89 f6 e8 7d ce 6e f8 4d 39 f4 0f 85 ea fe ff ff 4c 63 64 24 08 41 be ff ff ff 7f e9 38 ff ff ff e8 3f d4 6e f8 <48> 83 c4 38 5b 5d 41 5c 41 5d 41 5e 41 5f e9 4c df f2 01 e8 27 b8
RSP: 0018:ffffc90000a08d68 EFLAGS: 00000046
RAX: 0000000080010001 RBX: 0000000000000000 RCX: ffffffff8999dbbd
RDX: ffff888033c60000 RSI: ffffffff8999dd41 RDI: ffff888033c60000
RBP: ffff88805c696000 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000
R13: ffff88802c52fc00 R14: ffff88802c52fc00 R15: ffff88802c52fc00
FS:  00007fe69a5f66c0(0000) GS:ffff888124487000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2f90eff8 CR3: 000000005a1d7000 CR4: 00000000003526f0
Call Trace:
 <IRQ>
 advance_sched+0x66e/0xd20 net/sched/sch_taprio.c:984
 __run_hrtimer kernel/time/hrtimer.c:1930 [inline]
 __hrtimer_run_queues+0x470/0xa00 kernel/time/hrtimer.c:1994
 hrtimer_interrupt+0x3e5/0x940 kernel/time/hrtimer.c:2113
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
 __sysvec_apic_timer_interrupt+0x10b/0x460 arch/x86/kernel/apic/apic.c:1067
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline]
 sysvec_apic_timer_interrupt+0x9e/0xc0 arch/x86/kernel/apic/apic.c:1061
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:check_kcov_mode kernel/kcov.c:185 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x39/0x70 kernel/kcov.c:217
Code: 65 48 8b 15 81 de 00 12 a9 00 01 ff 00 74 1b f6 c4 01 74 07 a9 00 00 ff 00 74 05 c3 cc cc cc cc 8b 82 ec 16 00 00 85 c0 74 f1 <8b> 82 c8 16 00 00 83 f8 02 75 e6 48 8b 8a d0 16 00 00 8b 92 cc 16
RSP: 0018:ffffc9000627f740 EFLAGS: 00000246
RAX: 0000000080000000 RBX: 0000000000000001 RCX: ffffffff82b95bc9
RDX: ffff888033c60000 RSI: ffffffff82b95b02 RDI: ffff888033c60000
RBP: ffff888026e91690 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000
R13: dffffc0000000000 R14: 0000000000000000 R15: 0000000000000000
 kernfs_root+0x52/0x2a0 fs/kernfs/kernfs-internal.h:75
 kernfs_root_is_locked fs/kernfs/kernfs-internal.h:108 [inline]
 kernfs_rcu_name fs/kernfs/kernfs-internal.h:118 [inline]
 kernfs_sd_compare fs/kernfs/dir.c:366 [inline]
 kernfs_link_sibling+0x2f1/0x850 fs/kernfs/dir.c:397
 kernfs_add_one+0x1e7/0x850 fs/kernfs/dir.c:845
 __kernfs_create_file+0x295/0x350 fs/kernfs/file.c:1086
 sysfs_add_file_mode_ns+0x207/0x3c0 fs/sysfs/file.c:313
 create_files fs/sysfs/group.c:82 [inline]
 internal_create_group+0x593/0xfb0 fs/sysfs/group.c:189
 internal_create_groups+0x9d/0x150 fs/sysfs/group.c:229
 setup_gid_attrs drivers/infiniband/core/sysfs.c:1118 [inline]
 ib_setup_port_attrs+0x41f/0x600 drivers/infiniband/core/sysfs.c:1394
 add_one_compat_dev+0x5b3/0x820 drivers/infiniband/core/device.c:978
 rdma_dev_init_net+0x30a/0x590 drivers/infiniband/core/device.c:1194
 ops_init+0x1e2/0x5f0 net/core/net_namespace.c:137
 setup_net+0x118/0x3a0 net/core/net_namespace.c:446
 copy_net_ns+0x46f/0x7c0 net/core/net_namespace.c:579
 create_new_namespaces+0x3ea/0xac0 kernel/nsproxy.c:132
 unshare_nsproxy_namespaces+0xf2/0x220 kernel/nsproxy.c:234
 ksys_unshare+0x438/0xab0 kernel/fork.c:3242
 __do_sys_unshare kernel/fork.c:3316 [inline]
 __se_sys_unshare kernel/fork.c:3314 [inline]
 __x64_sys_unshare+0x31/0x40 kernel/fork.c:3314
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe69c39ce59
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:00007fe69a5f6028 EFLAGS: 00000246 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 00007fe69c615fa0 RCX: 00007fe69c39ce59
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000062040200
RBP: 00007fe69c432d6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fe69c616038 R14: 00007fe69c615fa0 R15: 00007ffe3c576438
 </TASK>
rcu: rcu_preempt kthread starved for 10502 jiffies! g87817 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:27848 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5388 [inline]
 __schedule+0x1295/0x67a0 kernel/sched/core.c:7189
 __schedule_loop kernel/sched/core.c:7268 [inline]
 schedule+0xdd/0x390 kernel/sched/core.c:7283
 schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x1a9/0x900 kernel/rcu/tree.c:2095
 rcu_gp_kthread+0x179/0x230 kernel/rcu/tree.c:2297
 kthread+0x370/0x450 kernel/kthread.c:436
 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 UID: 0 PID: 8538 Comm: kworker/u8:25 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0x589/0x1700 kernel/smp.c:892
Code: b8 00 00 00 00 00 fc ff df 48 8b 54 24 08 49 89 d5 49 89 d4 49 c1 ed 03 41 83 e4 07 49 01 c5 41 83 c4 03 e8 a9 83 0c 00 f3 90 <41> 0f b6 45 00 41 38 c4 7c 08 84 c0 0f 85 63 0f 00 00 8b 45 08 31
RSP: 0018:ffffc90004b47870 EFLAGS: 00000293
RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff81fc2dfd
RDX: ffff8880233e2540 RSI: ffffffff81fc2dd7 RDI: ffff8880233e2540
RBP: ffff8880b8541180 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000003
R13: ffffed10170a8231 R14: 0000000000000001 R15: ffff8880b843c800
FS:  0000000000000000(0000) GS:ffff888124387000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fce205eb078 CR3: 000000000e596000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1057
 on_each_cpu include/linux/smp.h:72 [inline]
 smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2773 [inline]
 smp_text_poke_batch_finish+0x337/0xc60 arch/x86/kernel/alternative.c:2983
 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
 jump_label_update+0x37a/0x550 kernel/jump_label.c:910
 static_key_enable_cpuslocked+0x1bc/0x270 kernel/jump_label.c:210
 static_key_enable+0x1a/0x20 kernel/jump_label.c:223
 toggle_allocation_gate mm/kfence/core.c:906 [inline]
 toggle_allocation_gate+0xfe/0x2d0 mm/kfence/core.c:898
 process_one_work+0xa0e/0x1980 kernel/workqueue.c:3314
 process_scheduled_works kernel/workqueue.c:3397 [inline]
 worker_thread+0x5ef/0xe50 kernel/workqueue.c:3478
 kthread+0x370/0x450 kernel/kthread.c:436
 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
IPVS: wlc: UDP 224.0.0.2:0 - no destination available
IPVS: wlc: UDP 224.0.0.2:0 - no destination available
IPVS: wlc: UDP 224.0.0.2:0 - no destination available
IPVS: wlc: UDP 224.0.0.2:0 - no destination available
IPVS: wlc: UDP 224.0.0.2:0 - no destination available
IPVS: wlc: UDP 224.0.0.2:0 - no destination available
IPVS: wlc: UDP 224.0.0.2:0 - no destination available
IPVS: wlc: UDP 224.0.0.2:0 - no destination available