syzbot

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P5823/1:b..l
rcu: 	(detected by 0, t=10503 jiffies, g=14869, q=1159 ncpus=2)
task:kworker/1:4     state:R  running task     stack:23448 pid:5823  tgid:5823  ppid:2      task_flags:0x4208060 flags:0x00080000
Workqueue: mld mld_mca_work
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5325 [inline]
 __schedule+0x1190/0x5de0 kernel/sched/core.c:6929
 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7256
 irqentry_exit+0x36/0x90 kernel/entry/common.c:211
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:lock_acquire+0x62/0x350 kernel/locking/lockdep.c:5872
Code: 94 08 12 83 f8 07 0f 87 bc 02 00 00 89 c0 48 0f a3 05 12 11 e9 0e 0f 82 74 02 00 00 8b 35 8a 41 e9 0e 85 f6 0f 85 8d 00 00 00 <48> 8b 44 24 30 65 48 2b 05 29 94 08 12 0f 85 c7 02 00 00 48 83 c4
RSP: 0018:ffffc90003e1f468 EFLAGS: 00000206
RAX: 0000000000000046 RBX: ffffffff8e3c4660 RCX: 00000000161bb5ea
RDX: 0000000000000000 RSI: ffffffff8da05660 RDI: ffffffff8bf07040
RBP: 0000000000000002 R08: a24342496ccab805 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 rcu_read_lock include/linux/rcupdate.h:867 [inline]
 class_rcu_constructor include/linux/rcupdate.h:1195 [inline]
 unwind_next_frame+0xd1/0x20a0 arch/x86/kernel/unwind_orc.c:479
 arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
 save_stack+0x160/0x1f0 mm/page_owner.c:156
 __reset_page_owner+0x84/0x1a0 mm/page_owner.c:311
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1394 [inline]
 __free_frozen_pages+0x7df/0x1160 mm/page_alloc.c:2906
 discard_slab mm/slub.c:3326 [inline]
 __put_partials+0x130/0x170 mm/slub.c:3872
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x4d/0x120 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x195/0x1e0 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:352
 kasan_slab_alloc include/linux/kasan.h:252 [inline]
 slab_post_alloc_hook mm/slub.c:4970 [inline]
 slab_alloc_node mm/slub.c:5280 [inline]
 kmem_cache_alloc_node_noprof+0x28a/0x770 mm/slub.c:5332
 kmalloc_reserve+0x18b/0x2c0 net/core/skbuff.c:579
 __alloc_skb+0x166/0x380 net/core/skbuff.c:670
 alloc_skb include/linux/skbuff.h:1383 [inline]
 igmp6_send+0x1d4/0x1570 net/ipv6/mcast.c:2184
 mld_mca_work+0xd0/0x1c0 net/ipv6/mcast.c:2723
 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3263
 process_scheduled_works kernel/workqueue.c:3346 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3427
 kthread+0x3c5/0x780 kernel/kthread.c:463
 ret_from_fork+0x675/0x7d0 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>