INFO: task syz.6.24837:31063 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.6.24837     state:D stack:27568 pid:31063 tgid:31061 ppid:24968  task_flags:0x400040 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5504 [inline]
 __schedule+0x17d9/0x56c0 kernel/sched/core.c:7228
 __schedule_loop kernel/sched/core.c:7307 [inline]
 schedule+0x164/0x360 kernel/sched/core.c:7322
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7379
 __mutex_lock_common kernel/locking/mutex.c:726 [inline]
 __mutex_lock+0x7bf/0x1550 kernel/locking/mutex.c:821
 nfsd_nl_listener_get_doit+0x104/0x610 fs/nfsd/nfsctl.c:2098
 genl_family_rcv_msg_doit+0x233/0x340 net/netlink/genetlink.c:1114
 genl_family_rcv_msg net/netlink/genetlink.c:1194 [inline]
 genl_rcv_msg+0x614/0x7a0 net/netlink/genetlink.c:1209
 netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2556
 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218
 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
 netlink_unicast+0x7bb/0x940 net/netlink/af_netlink.c:1345
 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1900
 sock_sendmsg_nosec net/socket.c:775 [inline]
 __sock_sendmsg net/socket.c:790 [inline]
 ____sys_sendmsg+0x9b9/0xa20 net/socket.c:2684
 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2738
 __sys_sendmsg net/socket.c:2770 [inline]
 __do_sys_sendmsg net/socket.c:2775 [inline]
 __se_sys_sendmsg net/socket.c:2773 [inline]
 __x64_sys_sendmsg+0x1b1/0x290 net/socket.c:2773
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f460a79ce59
RSP: 002b:00007f460b56e028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f460aa16090 RCX: 00007f460a79ce59
RDX: 0000000020040000 RSI: 0000200000000140 RDI: 0000000000000005
RBP: 00007f460a832e6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f460aa16128 R14: 00007f460aa16090 R15: 00007fff37431f98
 </TASK>
INFO: lockdep is turned off.
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
 __sys_info lib/sys_info.c:157 [inline]
 sys_info+0x135/0x170 lib/sys_info.c:165
 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]
 watchdog+0xfd7/0x1030 kernel/hung_task.c:561
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 5705 Comm: kworker/0:4 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Workqueue: mld mld_dad_work
RIP: 0010:memset_orig+0x3e/0xb0 arch/x86/lib/memset_64.S:72
Code: c1 41 89 f9 41 83 e1 07 75 74 48 89 d1 48 c1 e9 06 74 39 66 0f 1f 84 00 00 00 00 00 48 ff c9 48 89 07 48 89 47 08 48 89 47 10 <48> 89 47 18 48 89 47 20 48 89 47 28 48 89 47 30 48 89 47 38 48 8d
RSP: 0018:ffffc90000007b28 EFLAGS: 00000206
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000005
RDX: 0000000000000200 RSI: 0000000000000000 RDI: ffffc90000007bb0
RBP: ffffc90000007d60 R08: dffffc0000000000 R09: 0000000000000000
R10: ffffc90000007b30 R11: fffffbfff206229f R12: ffff8880834f9140
R13: 0000000000000000 R14: ffff8880834f96a0 R15: ffffc90000007b30
FS:  0000000000000000(0000) GS:ffff88812527b000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000563536865138 CR3: 000000003669c000 CR4: 00000000003526f0
Call Trace:
 <IRQ>
 kasan_save_stack mm/kasan/common.c:54 [inline]
 kasan_save_track+0x2f/0x80 mm/kasan/common.c:78
 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:253 [inline]
 __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2700 [inline]
 slab_free mm/slub.c:6310 [inline]
 kmem_cache_free+0x182/0x650 mm/slub.c:6437
 rcu_do_batch kernel/rcu/tree.c:2645 [inline]
 rcu_core+0x78b/0x10a0 kernel/rcu/tree.c:2897
 handle_softirqs+0x225/0x840 kernel/softirq.c:622
 do_softirq+0x76/0xd0 kernel/softirq.c:523
 </IRQ>
 <TASK>
 __local_bh_enable_ip+0xf8/0x130 kernel/softirq.c:450
 local_bh_enable include/linux/bottom_half.h:33 [inline]
 __alloc_skb+0x1ad/0x7a0 net/core/skbuff.c:699
 alloc_skb include/linux/skbuff.h:1386 [inline]
 mld_newpack+0x165/0xcb0 net/ipv6/mcast.c:1773
 add_grhead net/ipv6/mcast.c:1884 [inline]
 add_grec+0x119f/0x19d0 net/ipv6/mcast.c:2023
 mld_send_initial_cr+0x288/0x550 net/ipv6/mcast.c:2268
 mld_dad_work+0x3d/0x5a0 net/ipv6/mcast.c:2294
 process_one_work kernel/workqueue.c:3314 [inline]
 process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3397
 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3478
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>