INFO: task syz.1.330:7155 blocked for more than 143 seconds.
      Not tainted 6.11.0-rc7-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.330       state:D stack:21976 pid:7155  tgid:7155  ppid:6106   flags:0x00000004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5188 [inline]
 __schedule+0x1800/0x4a60 kernel/sched/core.c:6529
 __schedule_loop kernel/sched/core.c:6606 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6621
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6678
 __mutex_lock_common kernel/locking/mutex.c:684 [inline]
 __mutex_lock+0x6a4/0xd70 kernel/locking/mutex.c:752
 eventpoll_release_file+0xcb/0x1c0 fs/eventpoll.c:1106
 eventpoll_release include/linux/eventpoll.h:53 [inline]
 __fput+0x6e0/0x8a0 fs/file_table.c:413
 task_work_run+0x251/0x310 kernel/task_work.c:228
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x168/0x370 kernel/entry/common.c:218
 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd4a377def9
RSP: 002b:00007ffde56014f8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007fd4a3937a80 RCX: 00007fd4a377def9
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007fd4a3937a80 R08: 0000000000000006 R09: 00007ffde56017ef
R10: 00000000003ffd04 R11: 0000000000000246 R12: 0000000000044928
R13: 00007ffde5601600 R14: 0000000000000032 R15: ffffffffffffffff
 </TASK>

Showing all locks held in the system:
3 locks held by kworker/u8:0/11:
3 locks held by kworker/1:0/25:
 #0: ffff8880b883e9d8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xb0/0x140 kernel/sched/core.c:568
 #1: ffffc900001f7d00 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3207 [inline]
 #1: ffffc900001f7d00 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_scheduled_works+0x945/0x1830 kernel/workqueue.c:3312
 #2: ffff8880b892a718 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x112/0x240 kernel/time/timer.c:1051
1 lock held by khungtaskd/30:
 #0: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline]
 #0: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
 #0: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6626
3 locks held by kworker/u8:3/52:
3 locks held by kworker/0:2/935:
 #0: ffff88801ac78948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3206 [inline]
 #0: ffff88801ac78948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x90a/0x1830 kernel/workqueue.c:3312
 #1: ffffc90003a8fd00 (deferred_process_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3207 [inline]
 #1: ffffc90003a8fd00 (deferred_process_work){+.+.}-{0:0}, at: process_scheduled_works+0x945/0x1830 kernel/workqueue.c:3312
 #2: ffff8880276ac618 (&p->pi_lock){-.-.}-{2:2}, at: class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:551 [inline]
 #2: ffff8880276ac618 (&p->pi_lock){-.-.}-{2:2}, at: try_to_wake_up+0xb0/0x1470 kernel/sched/core.c:4051
4 locks held by kworker/u8:6/1110:
1 lock held by dhcpcd/4893:
2 locks held by getty/4982:
 #0: ffff8880305a40a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc90002f162f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6ac/0x1e00 drivers/tty/n_tty.c:2211
3 locks held by kworker/1:6/5326:
 #0: ffff88801ac78948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3206 [inline]
 #0: ffff88801ac78948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x90a/0x1830 kernel/workqueue.c:3312
 #1: ffffc9000477fd00 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3207 [inline]
 #1: ffffc9000477fd00 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_scheduled_works+0x945/0x1830 kernel/workqueue.c:3312
 #2: ffff88802f488240 (&data->fib_lock){+.+.}-{3:3}, at: nsim_fib_event_work+0x2d1/0x4130 drivers/net/netdevsim/fib.c:1489
3 locks held by kworker/u8:10/5667:
 #0: ffff88801bae5948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3206 [inline]
 #0: ffff88801bae5948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x90a/0x1830 kernel/workqueue.c:3312
 #1: ffffc9000311fd00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3207 [inline]
 #1: ffffc9000311fd00 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x945/0x1830 kernel/workqueue.c:3312
 #2: ffffffff8fc7f890 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x16a/0xcc0 net/core/net_namespace.c:594
1 lock held by syz.1.330/7155:
 #0: ffff88806c26d068 (&ep->mtx){+.+.}-{3:3}, at: eventpoll_release_file+0xcb/0x1c0 fs/eventpoll.c:1106
3 locks held by syz.1.330/7157:
1 lock held by syz-executor/7637:
 #0: ffffffff8e93d6f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:328 [inline]
 #0: ffffffff8e93d6f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x451/0x830 kernel/rcu/tree_exp.h:958
1 lock held by syz-executor/7648:
 #0: ffffffff8e93d6f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:296 [inline]
 #0: ffffffff8e93d6f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x381/0x830 kernel/rcu/tree_exp.h:958
1 lock held by sed/7726:

=============================================

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.11.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:93 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119
 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline]
 watchdog+0xff4/0x1040 kernel/hung_task.c:379
 kthread+0x2f2/0x390 kernel/kthread.c:389
 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 11 Comm: kworker/u8:0 Not tainted 6.11.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
Workqueue: ipv6_addrconf addrconf_dad_work
RIP: 0010:get_current arch/x86/include/asm/current.h:49 [inline]
RIP: 0010:task_capc mm/page_alloc.c:583 [inline]
RIP: 0010:__free_one_page+0x8b/0x8a0 mm/page_alloc.c:768
Code: 05 8e 48 c7 44 24 70 d0 cc ec 81 48 8d 54 24 60 48 c1 ea 03 48 b8 f1 f1 f1 f1 00 f3 f3 f3 48 89 d1 48 89 54 24 58 4a 89 04 2a <65> 4c 8b 3c 25 00 d7 03 00 49 8d 9f 90 12 00 00 48 89 d8 48 c1 e8
RSP: 0018:ffffc90000106ea0 EFLAGS: 00000012
RAX: f3f3f300f1f1f1f1 RBX: ffffea0001abf050 RCX: 1ffff92000020de0
RDX: 1ffff92000020de0 RSI: 000000000006afc1 RDI: ffffea0001abf040
RBP: ffffc90000106f88 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: fffffbfff2030ee6 R12: 0000000000000000
R13: dffffc0000000000 R14: 000000000006afc1 R15: ffffea0001abf040
FS:  0000000000000000(0000) GS:ffff8880b8900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055ecbccd7950 CR3: 0000000029268000 CR4: 0000000000350ef0
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 free_pcppages_bulk+0x3d3/0x5e0 mm/page_alloc.c:1194
 free_unref_page_commit+0x582/0x1140 mm/page_alloc.c:2594
 free_unref_page+0x622/0xea0 mm/page_alloc.c:2642
 discard_slab mm/slub.c:2587 [inline]
 __put_partials+0xeb/0x130 mm/slub.c:3055
 put_cpu_partial+0x17c/0x250 mm/slub.c:3130
 __slab_free+0x2ea/0x3d0 mm/slub.c:4347
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x9e/0x140 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:322
 kasan_slab_alloc include/linux/kasan.h:201 [inline]
 slab_post_alloc_hook mm/slub.c:3992 [inline]
 slab_alloc_node mm/slub.c:4041 [inline]
 kmem_cache_alloc_node_noprof+0x16b/0x320 mm/slub.c:4084
 __alloc_skb+0x1c3/0x440 net/core/skbuff.c:664
 alloc_skb include/linux/skbuff.h:1320 [inline]
 alloc_skb_with_frags+0xc3/0x770 net/core/skbuff.c:6526
 sock_alloc_send_pskb+0x91a/0xa60 net/core/sock.c:2815
 sock_alloc_send_skb include/net/sock.h:1778 [inline]
 mld_newpack+0x1c3/0xa90 net/ipv6/mcast.c:1746
 add_grhead net/ipv6/mcast.c:1849 [inline]
 add_grec+0x1492/0x19a0 net/ipv6/mcast.c:1987
 mld_send_initial_cr+0x228/0x4b0 net/ipv6/mcast.c:2233
 ipv6_mc_dad_complete+0x88/0x490 net/ipv6/mcast.c:2244
 addrconf_dad_completed+0x712/0xcd0 net/ipv6/addrconf.c:4340
 addrconf_dad_work+0xdc2/0x16f0
 process_one_work kernel/workqueue.c:3231 [inline]
 process_scheduled_works+0xa2e/0x1830 kernel/workqueue.c:3312
 worker_thread+0x86d/0xd10 kernel/workqueue.c:3389
 kthread+0x2f2/0x390 kernel/kthread.c:389
 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>