INFO: task kworker/u4:4:1442 blocked for more than 143 seconds.
      Not tainted 5.15.180-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u4:4    state:D stack:21856 pid: 1442 ppid:     2 flags:0x00004000
Workqueue: writeback wb_workfn (flush-7:0)
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
 f2fs_balance_fs+0x4d4/0x6a0 fs/f2fs/segment.c:528
 f2fs_write_inode+0x4be/0x660 fs/f2fs/inode.c:738
 write_inode fs/fs-writeback.c:1495 [inline]
 __writeback_single_inode+0x644/0xe30 fs/fs-writeback.c:1705
 writeback_sb_inodes+0xbce/0x1a40 fs/fs-writeback.c:1930
 __writeback_inodes_wb+0x114/0x400 fs/fs-writeback.c:2001
 wb_writeback+0x465/0xc50 fs/fs-writeback.c:2106
 wb_check_background_flush fs/fs-writeback.c:2172 [inline]
 wb_do_writeback fs/fs-writeback.c:2260 [inline]
 wb_workfn+0xd07/0x1130 fs/fs-writeback.c:2288
 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310
 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457
 kthread+0x3f6/0x4f0 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffffffff8cb1f4e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
4 locks held by kworker/u4:4/1442:
 #0: ffff888141fc8938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283
 #1: ffffc90005b17d20 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285
 #2: ffff8880260320e0 (&type->s_umount_key#43){.+.+}-{3:3}, at: trylock_super+0x1b/0xf0 fs/super.c:418
 #3: ffff88802bd6d1b0 (&sbi->gc_lock){+.+.}-{3:3}, at: f2fs_balance_fs+0x4d4/0x6a0 fs/f2fs/segment.c:528
2 locks held by getty/3923:
 #0: ffff88802cb6f098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
 #1: ffffc900025ae2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6af/0x1db0 drivers/tty/n_tty.c:2158
5 locks held by syz-executor233/4169:

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

NMI backtrace for cpu 0
CPU: 0 PID: 27 Comm: khungtaskd Not tainted 5.15.180-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+0x1e3/0x2d0 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:212 [inline]
 watchdog+0xe72/0xeb0 kernel/hung_task.c:369
 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
CPU: 1 PID: 4169 Comm: syz-executor233 Not tainted 5.15.180-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
RIP: 0010:__lock_acquire+0x153/0x1ff0 kernel/locking/lockdep.c:4918
Code: bf 15 00 00 83 3d 9c 92 46 15 00 75 09 83 fd 30 0f 83 d3 13 00 00 44 89 7c 24 2c 44 8b bc 24 d0 00 00 00 48 c7 c0 80 3f 31 90 <48> 29 c3 48 c1 fb 06 48 b8 ab aa aa aa aa aa aa aa 48 0f af c3 48
RSP: 0018:ffffc900031be700 EFLAGS: 00000087
RAX: ffffffff90313f80 RBX: ffffffff90314f40 RCX: ffffffff96a92f03
RDX: dffffc0000000000 RSI: 0000000000000000 RDI: ffffffff8cb1f4e0
RBP: 0000000000000007 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000000
R13: ffff888020b38000 R14: 0000000000000002 R15: 0000000000000000
FS:  000055557ab41380(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005569229a8600 CR3: 0000000024015000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623
 rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:312
 rcu_read_lock include/linux/rcupdate.h:739 [inline]
 percpu_ref_get_many include/linux/percpu-refcount.h:202 [inline]
 percpu_ref_get include/linux/percpu-refcount.h:222 [inline]
 blkg_get+0x1a/0x1a0 include/linux/blk-cgroup.h:468
 bio_associate_blkg_from_css+0x179/0x960 block/blk-cgroup.c:1868
 bio_associate_blkg+0x220/0x330 block/blk-cgroup.c:1894
 f2fs_target_device fs/f2fs/data.c:373 [inline]
 f2fs_grab_read_bio+0x351/0x720 fs/f2fs/data.c:997
 f2fs_submit_page_read+0xb8/0x2c0 fs/f2fs/data.c:1035
 f2fs_get_read_data_page+0x455/0x6b0 fs/f2fs/data.c:1224
 f2fs_get_lock_data_page+0x54/0x250 fs/f2fs/data.c:1271
 move_data_page fs/f2fs/gc.c:1336 [inline]
 gc_data_segment fs/f2fs/gc.c:1547 [inline]
 do_garbage_collect+0x3645/0x7540 fs/f2fs/gc.c:1671
 f2fs_gc+0x9d2/0x1c30 fs/f2fs/gc.c:1765
 f2fs_balance_fs+0x4e8/0x6a0 fs/f2fs/segment.c:529
 f2fs_map_blocks+0x2d56/0x3720 fs/f2fs/data.c:1746
 expand_inode_data+0x5dd/0xa40 fs/f2fs/file.c:1716
 f2fs_fallocate+0x435/0x910 fs/f2fs/file.c:1818
 vfs_fallocate+0x54a/0x6b0 fs/open.c:308
 file_ioctl fs/ioctl.c:-1 [inline]
 do_vfs_ioctl+0x2317/0x2b70 fs/ioctl.c:853
 __do_sys_ioctl fs/ioctl.c:872 [inline]
 __se_sys_ioctl+0x81/0x160 fs/ioctl.c:860
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0x80 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f7ae0e83d59
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 17 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffc0f9dd2e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00002000000000c0 RCX: 00007f7ae0e83d59
RDX: 00002000000000c0 RSI: 0000000040305828 RDI: 0000000000000004
RBP: 00002000000000e0 R08: 000055557ab424c0 R09: 000055557ab424c0
R10: 0000000000000000 R11: 0000000000000246 R12: 00002000000000d0
R13: 00002000000000c8 R14: 00002000000000c2 R15: 00007f7ae0ecd03b
 </TASK>
INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.521 msecs