INFO: task syz-executor:3634 blocked for more than 144 seconds.
      Not tainted 6.1.102-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:21208 pid:3634  ppid:1      flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5244 [inline]
 __schedule+0x143f/0x4570 kernel/sched/core.c:6561
 schedule+0xbf/0x180 kernel/sched/core.c:6637
 schedule_timeout+0xac/0x300 kernel/time/timer.c:1941
 do_wait_for_common kernel/sched/completion.c:85 [inline]
 __wait_for_common kernel/sched/completion.c:106 [inline]
 wait_for_common kernel/sched/completion.c:117 [inline]
 wait_for_completion+0x350/0x610 kernel/sched/completion.c:138
 kthread_stop+0x1ab/0x690 kernel/kthread.c:709
 ext4_stop_mmpd+0x43/0xb0 fs/ext4/mmp.c:261
 ext4_put_super+0xb49/0x10e0 fs/ext4/super.c:1293
 generic_shutdown_super+0x130/0x340 fs/super.c:501
 kill_block_super+0x7a/0xe0 fs/super.c:1459
 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:179
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 exit_to_user_mode_loop+0xde/0x100 kernel/entry/common.c:177
 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210
 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
 syscall_exit_to_user_mode+0x60/0x270 kernel/entry/common.c:303
 do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:87
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f51df7785c7
RSP: 002b:00007fffaee59928 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f51df7e4784 RCX: 00007f51df7785c7
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fffaee599e0
RBP: 00007fffaee599e0 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007fffaee5aa60
R13: 00007f51df7e4784 R14: 00000000000228b4 R15: 00007fffaee5aaa0
 </TASK>
INFO: task kmmpd-loop4:5063 blocked for more than 145 seconds.
      Not tainted 6.1.102-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kmmpd-loop4     state:D stack:28024 pid:5063  ppid:2      flags:0x00024000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5244 [inline]
 __schedule+0x143f/0x4570 kernel/sched/core.c:6561
 schedule+0xbf/0x180 kernel/sched/core.c:6637
 percpu_rwsem_wait+0x3b9/0x450 kernel/locking/percpu-rwsem.c:162
 __percpu_down_read+0xe6/0x130 kernel/locking/percpu-rwsem.c:177
 percpu_down_read include/linux/percpu-rwsem.h:65 [inline]
 __sb_start_write include/linux/fs.h:1891 [inline]
 sb_start_write include/linux/fs.h:1966 [inline]
 write_mmp_block+0x2ee/0x390 fs/ext4/mmp.c:66
 kmmpd+0x263/0xa70 fs/ext4/mmp.c:246
 kthread+0x28d/0x320 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>

Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
 #0: ffffffff8d32af10 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xe30 kernel/rcu/tasks.h:516
1 lock held by rcu_tasks_trace/13:
 #0: ffffffff8d32b710 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xe30 kernel/rcu/tasks.h:516
1 lock held by khungtaskd/28:
 #0: ffffffff8d32ad40 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
 #0: ffffffff8d32ad40 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
 #0: ffffffff8d32ad40 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6494
3 locks held by kworker/u4:4/102:
2 locks held by getty/3395:
 #0: ffff88814bf43098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244
 #1: ffffc900031332f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6a7/0x1db0 drivers/tty/n_tty.c:2198
1 lock held by syz-executor/3634:
 #0: ffff88802782e0e0 (&type->s_umount_key#32){++++}-{3:3}, at: deactivate_super+0xa9/0xe0 fs/super.c:362
1 lock held by kmmpd-loop4/5063:
 #0: ffff88802782e460 (sb_writers#4){++++}-{0:0}, at: kmmpd+0x263/0xa70 fs/ext4/mmp.c:246
1 lock held by syz.4.635/5990:
 #0: ffff88802782e0e0 (&type->s_umount_key#32){++++}-{3:3}, at: iterate_supers+0xac/0x1e0 fs/super.c:744
1 lock held by syz.3.751/6378:
 #0: ffff88802782e0e0 (&type->s_umount_key#32){++++}-{3:3}, at: iterate_supers+0xac/0x1e0 fs/super.c:744
1 lock held by syz.2.900/6915:
 #0: ffff88802782e0e0 (&type->s_umount_key#32){++++}-{3:3}, at: iterate_supers+0xac/0x1e0 fs/super.c:744

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

NMI backtrace for cpu 1
CPU: 1 PID: 28 Comm: khungtaskd Not tainted 6.1.102-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+0x1e3/0x2cb lib/dump_stack.c:106
 nmi_cpu_backtrace+0x4e1/0x560 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x1b0/0x3f0 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: 3080 Comm: klogd Not tainted 6.1.102-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024
RIP: 0010:lockdep_enabled kernel/locking/lockdep.c:122 [inline]
RIP: 0010:lock_acquire+0x151/0x5a0 kernel/locking/lockdep.c:5638
Code: 65 8b 05 a2 0b 98 7e 85 c0 0f 85 88 01 00 00 65 48 8b 1d 12 02 98 7e 48 81 c3 dc 0a 00 00 48 89 d8 48 c1 e8 03 42 0f b6 04 28 <84> c0 0f 85 ea 02 00 00 83 3b 00 0f 85 5c 01 00 00 4c 8d bc 24 80
RSP: 0018:ffffc9000318f640 EFLAGS: 00000a03
RAX: 0000000000000000 RBX: ffff88807d6fc65c RCX: ffffffff816a6cdb
RDX: 0000000000000000 RSI: ffffffff8b5d5b80 RDI: ffffffff8b5d5b40
RBP: ffffc9000318f790 R08: dffffc0000000000 R09: fffffbfff1d337ae
R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff92000631ed0
R13: dffffc0000000000 R14: 0000000000000000 R15: 0000000000000001
FS:  00007fd077450380(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f5f2b6d4338 CR3: 000000007ed8c000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 __fs_reclaim_acquire mm/page_alloc.c:4674 [inline]
 fs_reclaim_acquire+0x83/0x120 mm/page_alloc.c:4688
 might_alloc include/linux/sched/mm.h:271 [inline]
 slab_pre_alloc_hook+0x2a/0x300 mm/slab.h:710
 slab_alloc_node mm/slub.c:3318 [inline]
 kmem_cache_alloc_node+0x52/0x310 mm/slub.c:3443
 __alloc_skb+0xde/0x670 net/core/skbuff.c:505
 alloc_skb include/linux/skbuff.h:1271 [inline]
 alloc_skb_with_frags+0xa4/0x740 net/core/skbuff.c:6168
 sock_alloc_send_pskb+0x915/0xa50 net/core/sock.c:2747
 unix_dgram_sendmsg+0x5b1/0x2050 net/unix/af_unix.c:1941
 sock_sendmsg_nosec net/socket.c:718 [inline]
 __sock_sendmsg net/socket.c:730 [inline]
 __sys_sendto+0x480/0x600 net/socket.c:2148
 __do_sys_sendto net/socket.c:2160 [inline]
 __se_sys_sendto net/socket.c:2156 [inline]
 __x64_sys_sendto+0xda/0xf0 net/socket.c:2156
 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: 0033:0x7fd0775b29b5
Code: 8b 44 24 08 48 83 c4 28 48 98 c3 48 98 c3 41 89 ca 64 8b 04 25 18 00 00 00 85 c0 75 26 45 31 c9 45 31 c0 b8 2c 00 00 00 0f 05 <48> 3d 00 f0 ff ff 76 7a 48 8b 15 44 c4 0c 00 f7 d8 64 89 02 48 83
RSP: 002b:00007ffea0713cd8 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007fd0775b29b5
RDX: 000000000000004d RSI: 00005609776fcb00 RDI: 0000000000000003
RBP: 00005609776f5910 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000004000 R11: 0000000000000246 R12: 0000000000000013
R13: 00007fd077740212 R14: 00007ffea0713dd8 R15: 0000000000000000
 </TASK>