INFO: task syz.4.1800:10997 blocked for more than 143 seconds.
      Not tainted 5.15.163-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.1800      state:D stack:26784 pid:10997 ppid: 10333 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5030 [inline]
 __schedule+0x12c4/0x45b0 kernel/sched/core.c:6376
 schedule+0x11b/0x1f0 kernel/sched/core.c:6459
 rwsem_down_write_slowpath+0xf0c/0x16a0 kernel/locking/rwsem.c:1165
 user_get_super+0xd3/0x250 fs/super.c:835
 quotactl_block fs/quota/quota.c:889 [inline]
 __do_sys_quotactl fs/quota/quota.c:953 [inline]
 __se_sys_quotactl+0x490/0x770 fs/quota/quota.c:915
 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: 0033:0x7f661a576f19
RSP: 002b:00007f66189f7048 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3
RAX: ffffffffffffffda RBX: 00007f661a706f60 RCX: 00007f661a576f19
RDX: 0000000000000000 RSI: 0000000020000c00 RDI: ffffffff80000201
RBP: 00007f661a5e5e68 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007f661a706f60 R15: 00007fffc53251e8
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffffffff8c91fb20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
2 locks held by getty/3266:
 #0: ffff8880245a4098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
 #1: ffffc9000229b2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6af/0x1db0 drivers/tty/n_tty.c:2158
3 locks held by kworker/0:6/3554:
 #0: ffff888011c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283
 #1: ffffc90003247d20 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285
 #2: ffff8880378ec240 (&data->fib_lock){+.+.}-{3:3}, at: nsim_fib_event_work+0x2cd/0x4120 drivers/net/netdevsim/fib.c:1478
4 locks held by kworker/u4:12/4099:
3 locks held by kworker/0:16/5377:
 #0: ffff888011c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283
 #1: ffffc90003807d20 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285
 #2: ffff88806016b240 (&data->fib_lock){+.+.}-{3:3}, at: nsim_fib_event_work+0x2cd/0x4120 drivers/net/netdevsim/fib.c:1478
2 locks held by syz-executor/9406:
 #0: ffff88807b6220e0 (&type->s_umount_key#82){++++}-{3:3}, at: deactivate_super+0xa9/0xe0 fs/super.c:365
 #1: ffffffff8ccbbf88 (jfs_log_mutex){+.+.}-{3:3}, at: lmLogClose+0xae/0x530 fs/jfs/jfs_logmgr.c:1452
2 locks held by syz-executor/9523:
 #0: ffff888015faa0e0 (&type->s_umount_key#82){++++}-{3:3}, at: deactivate_super+0xa9/0xe0 fs/super.c:365
 #1: ffffffff8ccbbf88 (jfs_log_mutex){+.+.}-{3:3}, at: lmLogClose+0xae/0x530 fs/jfs/jfs_logmgr.c:1452
2 locks held by syz-executor/10293:
 #0: ffff88807b8f80e0 (&type->s_umount_key#82){++++}-{3:3}, at: deactivate_super+0xa9/0xe0 fs/super.c:365
 #1: ffffffff8ccbbf88 (jfs_log_mutex){+.+.}-{3:3}, at: lmLogClose+0xae/0x530 fs/jfs/jfs_logmgr.c:1452
2 locks held by syz-executor/10510:
 #0: ffff88805bbe40e0 (&type->s_umount_key#82){++++}-{3:3}, at: deactivate_super+0xa9/0xe0 fs/super.c:365
 #1: ffffffff8ccbbf88 (jfs_log_mutex){+.+.}-{3:3}, at: lmLogClose+0xae/0x530 fs/jfs/jfs_logmgr.c:1452
1 lock held by syz.4.1800/10997:
 #0: ffff888015faa0e0 (&type->s_umount_key#82){++++}-{3:3}, at: user_get_super+0xd3/0x250 fs/super.c:835
1 lock held by syz.4.2331/12662:
 #0: ffff888015faa0e0 (&type->s_umount_key#82){++++}-{3:3}, at: user_get_super+0x11a/0x250 fs/super.c:837
1 lock held by syz.3.2473/13288:
 #0: ffff88807b8f80e0 (&type->s_umount_key#82){++++}-{3:3}, at: user_get_super+0x11a/0x250 fs/super.c:837
1 lock held by syz.4.2607/13690:
 #0: 
ffff888015faa0e0
 (&type->s_umount_key#82){++++}-{3:3}, at: user_get_super+0xd3/0x250 fs/super.c:835
1 lock held by syz.1.2543/13782:
 #0: ffff88805bbe40e0 (&type->s_umount_key#82){++++}-{3:3}, at: user_get_super+0x11a/0x250 fs/super.c:837
3 locks held by syz-executor/14007:
1 lock held by syz.3.2661/14031:
 #0: ffff88807b8f80e0 (&type->s_umount_key#82){++++}-{3:3}, at: user_get_super+0xd3/0x250 fs/super.c:835

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

NMI backtrace for cpu 1
CPU: 1 PID: 27 Comm: khungtaskd Not tainted 5.15.163-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024
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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 14007 Comm: syz-executor Not tainted 5.15.163-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024
RIP: 0010:io_serial_in+0x72/0xb0 drivers/tty/serial/8250/8250_port.c:461
Code: c4 7f 05 fd 89 e9 41 d3 e6 48 83 c3 40 48 89 d8 48 c1 e8 03 42 80 3c 38 00 74 08 48 89 df e8 35 52 4f fd 44 03 33 44 89 f2 ec <0f> b6 c0 5b 41 5e 41 5f 5d c3 89 e9 80 e1 07 38 c1 7c ad 48 89 ef
RSP: 0018:ffffc900015de330 EFLAGS: 00000002
RAX: 1ffffffff22e3400 RBX: ffffffff9171a780 RCX: 0000000000000000
RDX: 00000000000003fd RSI: 0000000000000000 RDI: 0000000000000020
RBP: 0000000000000000 R08: ffffffff847ade42 R09: 0000000000000003
R10: ffffffffffffffff R11: dffffc0000000001 R12: 1ffffffff22e353d
R13: ffffffff9171a740 R14: 00000000000003fd R15: dffffc0000000000
FS:  0000555555658500(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f46c934f440 CR3: 0000000037cee000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 serial_in drivers/tty/serial/8250/8250.h:116 [inline]
 wait_for_xmitr+0xec/0x260 drivers/tty/serial/8250/8250_port.c:2069
 serial8250_console_putchar+0x19/0x50 drivers/tty/serial/8250/8250_port.c:3301
 uart_console_write+0xa9/0x100 drivers/tty/serial/serial_core.c:1971
 serial8250_console_write+0xc8e/0x1180 drivers/tty/serial/8250/8250_port.c:3378
 console_unlock+0xced/0x12b0 kernel/printk/printk.c:2744
 vprintk_emit+0xbf/0x150 kernel/printk/printk.c:2274
 _printk+0xd1/0x120 kernel/printk/printk.c:2299
 batadv_hardif_activate_interface+0x15d/0x390 net/batman-adv/hard-interface.c:671
 batadv_hard_if_event+0xbc/0x17a0 net/batman-adv/hard-interface.c:965
 notifier_call_chain kernel/notifier.c:83 [inline]
 raw_notifier_call_chain+0xd0/0x170 kernel/notifier.c:391
 __dev_notify_flags+0x304/0x610
 dev_change_flags+0xe7/0x190 net/core/dev.c:8889
 do_setlink+0xcd1/0x3b00 net/core/rtnetlink.c:2741
 __rtnl_newlink net/core/rtnetlink.c:3429 [inline]
 rtnl_newlink+0x17a4/0x2070 net/core/rtnetlink.c:3549
 rtnetlink_rcv_msg+0x993/0xee0 net/core/rtnetlink.c:5629
 netlink_rcv_skb+0x1cf/0x410 net/netlink/af_netlink.c:2504
 netlink_unicast_kernel net/netlink/af_netlink.c:1326 [inline]
 netlink_unicast+0x7b6/0x980 net/netlink/af_netlink.c:1352
 netlink_sendmsg+0xa30/0xd60 net/netlink/af_netlink.c:1920
 sock_sendmsg_nosec net/socket.c:704 [inline]
 __sock_sendmsg net/socket.c:716 [inline]
 __sys_sendto+0x564/0x720 net/socket.c:2058
 __do_sys_sendto net/socket.c:2070 [inline]
 __se_sys_sendto net/socket.c:2066 [inline]
 __x64_sys_sendto+0xda/0xf0 net/socket.c:2066
 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: 0033:0x7f4a69a52cac
Code: 2a 5a 02 00 44 8b 4c 24 2c 4c 8b 44 24 20 89 c5 44 8b 54 24 28 48 8b 54 24 18 b8 2c 00 00 00 48 8b 74 24 10 8b 7c 24 08 0f 05 <48> 3d 00 f0 ff ff 77 34 89 ef 48 89 44 24 08 e8 70 5a 02 00 48 8b
RSP: 002b:00007ffd87b8eed0 EFLAGS: 00000293 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007f4a6a70f620 RCX: 00007f4a69a52cac
RDX: 000000000000002c RSI: 00007f4a6a70f670 RDI: 0000000000000003
RBP: 0000000000000000 R08: 00007ffd87b8ef24 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000003
R13: 0000000000000000 R14: 00007f4a6a70f670 R15: 0000000000000000
 </TASK>