INFO: task syz-executor:4409 blocked for more than 143 seconds.
      Not tainted 6.1.131-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:21024 pid:4409  ppid:1      flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5243 [inline]
 __schedule+0x143f/0x4570 kernel/sched/core.c:6560
 schedule+0xbf/0x180 kernel/sched/core.c:6636
 wb_wait_for_completion+0x162/0x290 fs/fs-writeback.c:191
 sync_inodes_sb+0x28f/0xb10 fs/fs-writeback.c:2739
 sync_filesystem+0x16b/0x220 fs/sync.c:64
 generic_shutdown_super+0x6b/0x340 fs/super.c:474
 kill_block_super+0x7a/0xe0 fs/super.c:1470
 deactivate_locked_super+0xa0/0x110 fs/super.c:332
 cleanup_mnt+0x490/0x520 fs/namespace.c:1186
 task_work_run+0x246/0x300 kernel/task_work.c:203
 exit_task_work include/linux/task_work.h:39 [inline]
 do_exit+0xa6e/0x26a0 kernel/exit.c:871
 do_group_exit+0x202/0x2b0 kernel/exit.c:1021
 __do_sys_exit_group kernel/exit.c:1032 [inline]
 __se_sys_exit_group kernel/exit.c:1030 [inline]
 __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1030
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fac6518d169
RSP: 002b:00007ffd4b614968 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007fac6520e0fe RCX: 00007fac6518d169
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001
RBP: 0000000000000010 R08: 00007ffd4b612706 R09: 00007ffd4b615c20
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffd4b615c20
R13: 00007fac6520e08c R14: 0000555588a604a8 R15: 00007ffd4b616cf0
 </TASK>

Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
 #0: ffffffff8d32e890 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xe30 kernel/rcu/tasks.h:517
1 lock held by rcu_tasks_trace/13:
 #0: ffffffff8d32f090 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xe30 kernel/rcu/tasks.h:517
3 locks held by kworker/0:1/14:
 #0: ffff888030339938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x806/0x1260 kernel/workqueue.c:2267
 #1: ffffc90000137d20 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x806/0x1260 kernel/workqueue.c:2267
 #2: ffffffff8e5505a8 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xcc/0x16e0 net/ipv6/addrconf.c:4134
2 locks held by kworker/1:1/26:
 #0: ffff888017c72138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x806/0x1260 kernel/workqueue.c:2267
 #1: ffffc90000a1fd20 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x806/0x1260 kernel/workqueue.c:2267
1 lock held by khungtaskd/28:
 #0: ffffffff8d32e6c0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
 #0: ffffffff8d32e6c0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
 #0: ffffffff8d32e6c0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6510
5 locks held by kworker/u4:3/46:
 #0: ffff888017e16938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x806/0x1260 kernel/workqueue.c:2267
 #1: ffffc90000b77d20 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x806/0x1260 kernel/workqueue.c:2267
 #2: ffffffff8e543a50 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x166/0xd20 net/core/net_namespace.c:594
 #3: ffffffff8e5505a8 (rtnl_mutex){+.+.}-{3:3}, at: ip6gre_exit_batch_net+0xc2/0x490 net/ipv6/ip6_gre.c:1666
 #4: ffffffff8d333cf8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:291 [inline]
 #4: ffffffff8d333cf8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x4f0/0x930 kernel/rcu/tree_exp.h:962
2 locks held by dhcpcd/3915:
 #0: ffffffff8e535fa8 (vlan_ioctl_mutex){+.+.}-{3:3}, at: sock_ioctl+0x526/0x770 net/socket.c:1283
 #1: ffffffff8e5505a8 (rtnl_mutex){+.+.}-{3:3}, at: vlan_ioctl_handler+0x114/0x980 net/8021q/vlan.c:554
2 locks held by getty/4005:
 #0: ffff888031939098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244
 #1: ffffc9000325e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x54a/0x1620 drivers/tty/n_tty.c:2198
3 locks held by kworker/1:6/4298:
 #0: ffff888030339938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x806/0x1260 kernel/workqueue.c:2267
 #1: ffffc900047cfd20 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x806/0x1260 kernel/workqueue.c:2267
 #2: ffffffff8e5505a8 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xcc/0x16e0 net/ipv6/addrconf.c:4134
2 locks held by syz-executor/4409:
 #0: ffff888054e280e0 (&type->s_umount_key#31){++++}-{3:3}, at: deactivate_super+0xa9/0xe0 fs/super.c:362
 #1: ffff88802518a7d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:362 [inline]
 #1: ffff88802518a7d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x270/0xb10 fs/fs-writeback.c:2737
3 locks held by kworker/u4:7/4460:
3 locks held by kworker/0:18/5275:
 #0: ffff888017c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x806/0x1260 kernel/workqueue.c:2267
 #1: ffffc90003c87d20 (deferred_process_work){+.+.}-{0:0}, at: process_one_work+0x806/0x1260 kernel/workqueue.c:2267
 #2: ffffffff8e5505a8 (rtnl_mutex){+.+.}-{3:3}, at: switchdev_deferred_process_work+0xa/0x20 net/switchdev/switchdev.c:104
1 lock held by syz.7.489/7111:
 #0: ffff888054e280e0 (&type->s_umount_key#31){++++}-{3:3}, at: iterate_supers+0xac/0x1e0 fs/super.c:755
1 lock held by syz.7.489/7112:
 #0: ffff888054e280e0 (&type->s_umount_key#31){++++}-{3:3}, at: iterate_supers+0xac/0x1e0 fs/super.c:755
1 lock held by syz.7.489/7113:
 #0: ffff888054e280e0 (&type->s_umount_key#31){++++}-{3:3}, at: iterate_supers+0xac/0x1e0 fs/super.c:755
1 lock held by syz-executor/7359:
 #0: ffffffff8e5505a8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline]
 #0: ffffffff8e5505a8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7cb/0x1000 net/core/rtnetlink.c:6147
1 lock held by syz-executor/7392:
 #0: ffffffff8e5505a8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline]
 #0: ffffffff8e5505a8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7cb/0x1000 net/core/rtnetlink.c:6147
1 lock held by syz-executor/7412:
 #0: ffffffff8e5505a8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline]
 #0: ffffffff8e5505a8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7cb/0x1000 net/core/rtnetlink.c:6147

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

NMI backtrace for cpu 1
CPU: 1 PID: 28 Comm: khungtaskd Not tainted 6.1.131-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
 nmi_cpu_backtrace+0x4e1/0x560 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x1ca/0x430 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline]
 watchdog+0xf88/0xfd0 kernel/hung_task.c:377
 kthread+0x28d/0x320 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 29 Comm: kworker/u4:2 Not tainted 6.1.131-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Workqueue: bat_events batadv_nc_worker
RIP: 0010:cpu_max_bits_warn include/linux/cpumask.h:110 [inline]
RIP: 0010:cpumask_check include/linux/cpumask.h:117 [inline]
RIP: 0010:cpumask_test_cpu include/linux/cpumask.h:444 [inline]
RIP: 0010:cpu_online include/linux/cpumask.h:1030 [inline]
RIP: 0010:trace_lock_acquire include/trace/events/lock.h:24 [inline]
RIP: 0010:lock_acquire+0xca/0x5a0 kernel/locking/lockdep.c:5633
Code: 0f 1f 44 00 00 65 8b 1d 94 65 97 7e 48 c7 c0 78 b6 a0 8e 48 c1 e8 03 42 0f b6 04 28 84 c0 0f 85 59 03 00 00 39 1d 4e 02 36 0d <0f> 86 e4 02 00 00 89 db 48 89 d8 48 c1 e8 06 48 8d 3c c5 68 b4 a0
RSP: 0018:ffffc90000a5f9e0 EFLAGS: 00000202
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88805d19ca98
RBP: ffffc90000a5fb30 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff9200014bf44
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff88805950ef10
FS:  0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f9e0e779178 CR3: 000000000d08e000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline]
 _raw_spin_lock_bh+0x31/0x40 kernel/locking/spinlock.c:178
 spin_lock_bh include/linux/spinlock.h:356 [inline]
 batadv_nc_purge_paths+0xe8/0x3b0 net/batman-adv/network-coding.c:442
 batadv_nc_worker+0x361/0x610 net/batman-adv/network-coding.c:722
 process_one_work+0x917/0x1260 kernel/workqueue.c:2292
 worker_thread+0xa47/0x1200 kernel/workqueue.c:2439
 kthread+0x28d/0x320 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>