INFO: task syz.0.3600:22418 blocked for more than 144 seconds.
      Not tainted 5.15.166-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.3600      state:D stack:25624 pid:22418 ppid: 21357 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5027 [inline]
 __schedule+0x12c4/0x45b0 kernel/sched/core.c:6373
 schedule+0x11b/0x1f0 kernel/sched/core.c:6456
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6515
 __mutex_lock_common+0xe34/0x25a0 kernel/locking/mutex.c:669
 __mutex_lock kernel/locking/mutex.c:729 [inline]
 mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
 exfat_sync_fs+0x67/0x100 fs/exfat/super.c:64
 iterate_supers+0x127/0x1e0 fs/super.c:716
 ksys_sync+0xd7/0x1c0 fs/sync.c:104
 __do_sys_sync+0xa/0x10 fs/sync.c:113
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f17be5caef9
RSP: 002b:00007f17bca44038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f17be783f80 RCX: 00007f17be5caef9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f17be63d046 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f17be783f80 R15: 00007ffe041e4e48
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffffffff8c91fbe0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
2 locks held by kworker/u4:3/1133:
1 lock held by dhcpcd/3237:
 #0: ffffffff8da31608 (rtnl_mutex){+.+.}-{3:3}, at: __netlink_dump_start+0x12e/0x6d0 net/netlink/af_netlink.c:2348
2 locks held by getty/3327:
 #0: ffff888029ded098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
 #1: ffffc9000209b2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6af/0x1db0 drivers/tty/n_tty.c:2158
3 locks held by kworker/1:9/4499:
 #0: ffff88814a845138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283
 #1: ffffc90003537d20 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285
 #2: ffffffff8da31608 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xcc/0x1720 net/ipv6/addrconf.c:4113
2 locks held by kworker/0:21/13991:
 #0: ffff888017072138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283
 #1: ffffc900038b7d20 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285
3 locks held by syz-executor/16879:
4 locks held by kworker/u4:9/17171:
 #0: ffff8880171d5938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283
 #1: ffffc90002f57d20 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285
 #2: ffffffff8da25a50 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0xf1/0xb60 net/core/net_namespace.c:561
 #3: ffffffff8da31608 (rtnl_mutex){+.+.}-{3:3}, at: ieee80211_unregister_hw+0x4d/0x220 net/mac80211/main.c:1390
2 locks held by syz-executor/21172:
 #0: ffff888020ea2118 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0xfb/0x790 block/bdev.c:912
 #1: ffff888147172468 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0xa9/0xbe0 drivers/block/loop.c:1365
3 locks held by kworker/0:0/21464:
 #0: ffff888017070938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283
 #1: ffffc90002f77d20 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285
 #2: ffff88804d96c400 (&nsim_dev->port_list_lock){+.+.}-{3:3}, at: nsim_dev_trap_report_work+0x56/0xab0 drivers/net/netdevsim/dev.c:757
2 locks held by syz.0.3600/22418:
 #0: ffff8880232a80e0 (&type->s_umount_key#51){++++}-{3:3}, at: iterate_supers+0xac/0x1e0 fs/super.c:714
 #1: ffff888022e2c0e0 (&sbi->s_lock){+.+.}-{3:3}, at: exfat_sync_fs+0x67/0x100 fs/exfat/super.c:64
2 locks held by syz.4.3869/23730:
 #0: ffff8880232a80e0 (&type->s_umount_key#51){++++}-{3:3}, at: iterate_supers+0xac/0x1e0 fs/super.c:714
 #1: ffff888022e2c0e0 (&sbi->s_lock){+.+.}-{3:3}, at: exfat_sync_fs+0x67/0x100 fs/exfat/super.c:64
1 lock held by syz-executor/23781:
 #0: ffffffff8da31608 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
 #0: ffffffff8da31608 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x94c/0xee0 net/core/rtnetlink.c:5615
8 locks held by syz-executor/23796:
 #0: ffff88807f6c0460 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x29a/0xe50 fs/read_write.c:590
 #1: ffff88807e084c88 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e7/0x4f0 fs/kernfs/file.c:287
 #2: ffff88814777fe88 (kn->active#232){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x20b/0x4f0 fs/kernfs/file.c:288
 #3: ffffffff8d373348 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xf1/0x470 drivers/net/netdevsim/bus.c:344
 #4: ffff88804d96b178 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:760 [inline]
 #4: ffff88804d96b178 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1044 [inline]
 #4: ffff88804d96b178 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xc2/0x7f0 drivers/base/dd.c:1259
 #5: ffff88804d96c400 (&nsim_dev->port_list_lock){+.+.}-{3:3}, at: nsim_dev_port_del_all drivers/net/netdevsim/dev.c:1359 [inline]
 #5: ffff88804d96c400 (&nsim_dev->port_list_lock){+.+.}-{3:3}, at: nsim_dev_reload_destroy+0x118/0x240 drivers/net/netdevsim/dev.c:1561
 #6: ffffffff8da31608 (rtnl_mutex){+.+.}-{3:3}, at: nsim_destroy+0x3a/0x140 drivers/net/netdevsim/netdev.c:381
 #7: ffffffff8c9241a8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline]
 #7: ffffffff8c9241a8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x280/0x740 kernel/rcu/tree_exp.h:845
2 locks held by syz.2.3898/23888:
 #0: ffff888055cc8210 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:789 [inline]
 #0: ffff888055cc8210 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: __sock_release net/socket.c:648 [inline]
 #0: ffff888055cc8210 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: sock_close+0x98/0x230 net/socket.c:1336
 #1: ffffffff8da31608 (rtnl_mutex){+.+.}-{3:3}, at: ip6mr_sk_done+0xa0/0x2a0 net/ipv6/ip6mr.c:1584
2 locks held by syz.2.3898/23889:
 #0: ffffffff8da19528 (br_ioctl_mutex){+.+.}-{3:3}, at: br_ioctl_call net/socket.c:1112 [inline]
 #0: ffffffff8da19528 (br_ioctl_mutex){+.+.}-{3:3}, at: sock_ioctl+0x26f/0x770 net/socket.c:1211
 #1: ffffffff8da31608 (rtnl_mutex){+.+.}-{3:3}, at: netdev_run_todo+0xa4f/0xc40 net/core/dev.c:10656
1 lock held by syz.2.3898/23896:
 #0: ffffffff8da19528 (br_ioctl_mutex){+.+.}-{3:3}, at: br_ioctl_call+0x53/0xa0 net/socket.c:1112

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

NMI backtrace for cpu 0
CPU: 0 PID: 27 Comm: khungtaskd Not tainted 5.15.166-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:88 [inline]
 dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x46a/0x4a0 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x181/0x2a0 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:210 [inline]
 watchdog+0xe72/0xeb0 kernel/hung_task.c:295
 kthread+0x3f6/0x4f0 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline]
NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline]
NMI backtrace for cpu 1 skipped: idling at acpi_safe_halt drivers/acpi/processor_idle.c:108 [inline]
NMI backtrace for cpu 1 skipped: idling at acpi_idle_do_entry+0x10f/0x340 drivers/acpi/processor_idle.c:562