INFO: task kworker/u8:0:12 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:0    state:D stack:19776 pid:12    tgid:12    ppid:2      task_flags:0x4208060 flags:0x00080000
Workqueue: writeback wb_workfn (flush-7:0)
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5388 [inline]
 __schedule+0x16ec/0x5620 kernel/sched/core.c:7189
 __schedule_loop kernel/sched/core.c:7268 [inline]
 rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7564
 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1662 [inline]
 __rt_mutex_slowlock kernel/locking/rtmutex.c:1739 [inline]
 __rt_mutex_slowlock_locked+0x1f28/0x2550 kernel/locking/rtmutex.c:1779
 rt_mutex_slowlock+0xbd/0x170 kernel/locking/rtmutex.c:1819
 __rt_mutex_lock kernel/locking/rtmutex.c:1834 [inline]
 rwbase_write_lock+0x14d/0x730 kernel/locking/rwbase_rt.c:245
 f2fs_down_write fs/f2fs/f2fs.h:2411 [inline]
 f2fs_down_write_trace fs/f2fs/checkpoint.c:180 [inline]
 f2fs_issue_checkpoint+0x437/0x790 fs/f2fs/checkpoint.c:2095
 f2fs_balance_fs_bg+0x574/0x9d0 fs/f2fs/segment.c:545
 f2fs_write_node_pages+0x158/0x700 fs/f2fs/node.c:2257
 do_writepages+0x32e/0x550 mm/page-writeback.c:2571
 __writeback_single_inode+0x133/0x10e0 fs/fs-writeback.c:1764
 writeback_sb_inodes+0x97f/0x1980 fs/fs-writeback.c:2056
 __writeback_inodes_wb+0x111/0x240 fs/fs-writeback.c:2132
 wb_writeback+0x459/0xb00 fs/fs-writeback.c:2243
 wb_check_old_data_flush fs/fs-writeback.c:2347 [inline]
 wb_do_writeback fs/fs-writeback.c:2400 [inline]
 wb_workfn+0xb17/0xf20 fs/fs-writeback.c:2428
 process_one_work kernel/workqueue.c:3314 [inline]
 process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3397
 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3478
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Showing all locks held in the system:
4 locks held by kworker/u8:0/12:
 #0: ffff88801fa90938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline]
 #0: ffff88801fa90938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3397
 #1: ffffc90000117c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline]
 #1: ffffc90000117c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397
 #2: ffff888033c740d0 (&type->s_umount_key#109){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:565
 #3: ffff88805c39da98 (&sbi->gc_lock){+.+.}-{4:4}, at: f2fs_down_write fs/f2fs/f2fs.h:2411 [inline]
 #3: ffff88805c39da98 (&sbi->gc_lock){+.+.}-{4:4}, at: f2fs_down_write_trace fs/f2fs/checkpoint.c:180 [inline]
 #3: ffff88805c39da98 (&sbi->gc_lock){+.+.}-{4:4}, at: f2fs_issue_checkpoint+0x437/0x790 fs/f2fs/checkpoint.c:2095
3 locks held by kworker/u8:1/13:
 #0: ffff88801a074138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline]
 #0: ffff88801a074138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3397
 #1: ffffc90000127c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline]
 #1: ffffc90000127c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397
 #2: ffffffff8f358db8 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:313
1 lock held by khungtaskd/38:
 #0: ffffffff8dfc8080 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
 #0: ffffffff8dfc8080 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
 #0: ffffffff8dfc8080 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by kworker/u8:5/73:
 #0: ffff88801a074138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline]
 #0: ffff88801a074138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3397
 #1: ffffc9000153fc40 (connector_reaper_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline]
 #1: ffffc9000153fc40 (connector_reaper_work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397
3 locks held by kworker/1:2/823:
 #0: ffff88801a037938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline]
 #0: ffff88801a037938 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3397
 #1: ffffc90003967c40 (rx_mode_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline]
 #1: ffffc90003967c40 (rx_mode_work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397
 #2: ffffffff8f358db8 (rtnl_mutex){+.+.}-{4:4}, at: netdev_rx_mode_work+0x1c/0x450 net/core/dev_addr_lists.c:1312
3 locks held by kworker/u8:10/1176:
 #0: ffff8880328a6138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline]
 #0: ffff8880328a6138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3397
 #1: ffffc9000644fc40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline]
 #1: ffffc9000644fc40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397
 #2: ffffffff8f358db8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
 #2: ffffffff8f358db8 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x124/0x1680 net/ipv6/addrconf.c:4206
5 locks held by kworker/u8:12/1195:
2 locks held by kworker/u8:13/1436:
 #0: ffff88801a074138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline]
 #0: ffff88801a074138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3397
 #1: ffffc90006edfc40 ((reaper_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline]
 #1: ffffc90006edfc40 ((reaper_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397
1 lock held by dhcpcd/5261:
 #0: ffffffff8f358db8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
 #0: ffffffff8f358db8 (rtnl_mutex){+.+.}-{4:4}, at: devinet_ioctl+0x32b/0x1b30 net/ipv4/devinet.c:1120
2 locks held by getty/5350:
 #0: ffff8880291100a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc90003cbe2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13a0 drivers/tty/n_tty.c:2211
6 locks held by syz.0.305/8331:
2 locks held by syz-executor/9491:
 #0: ffff88803ec82480 (sb_writers#5){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493
 #1: ffff888065c299f0 (&type->i_mutex_dir_key#5/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1074 [inline]
 #1: ffff888065c299f0 (&type->i_mutex_dir_key#5/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2914 [inline]
 #1: ffff888065c299f0 (&type->i_mutex_dir_key#5/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2938 [inline]
 #1: ffff888065c299f0 (&type->i_mutex_dir_key#5/1){+.+.}-{4:4}, at: filename_rmdir+0x1cd/0x520 fs/namei.c:5414
1 lock held by syz-executor/9821:
 #0: ffffffff8f358db8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
 #0: ffffffff8f358db8 (rtnl_mutex){+.+.}-{4:4}, at: inet6_rtm_newaddr+0x65f/0xe30 net/ipv6/addrconf.c:5039
1 lock held by syz-executor/9905:
 #0: ffffffff8f358db8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
 #0: ffffffff8f358db8 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x404/0x1ad0 net/ipv4/devinet.c:978
1 lock held by udevd/9953:
 #0: ffff888037b50480 (sb_writers#5){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493
1 lock held by syz-executor/10032:
 #0: ffffffff8f358db8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
 #0: ffffffff8f358db8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
 #0: ffffffff8f358db8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x883/0x1bb0 net/core/rtnetlink.c:4109
2 locks held by syz-executor/10110:
 #0: ffffffff8f893778 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
 #0: ffffffff8f893778 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
 #0: ffffffff8f893778 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570
 #1: ffffffff8f358db8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
 #1: ffffffff8f358db8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
 #1: ffffffff8f358db8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x883/0x1bb0 net/core/rtnetlink.c:4109

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 38 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
 __sys_info lib/sys_info.c:157 [inline]
 sys_info+0x135/0x170 lib/sys_info.c:165
 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]
 watchdog+0xfd3/0x1030 kernel/hung_task.c:561
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 8331 Comm: syz.0.305 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:down_read+0x5/0x200 kernel/locking/rwsem.c:1566
Code: 90 e9 00 fe ff ff 90 0f 0b 90 e9 fb fe ff ff cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 55 <48> 89 e5 41 57 41 56 41 55 41 54 53 48 83 e4 e0 48 83 ec 60 48 89
RSP: 0018:ffffc900043b6ea0 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 0000000000000017 RCX: 0000000000080000
RDX: ffffc90007552000 RSI: 000000000007ffff RDI: ffff88806032e150
RBP: 0000000000000017 R08: 0000000000000004 R09: 0000000000000004
R10: ffffc900043b6f94 R11: fffff52000876df4 R12: ffffc900043b6f90
R13: ffff88805c39c150 R14: ffff88806032e000 R15: ffff88806032e150
FS:  00007f73b29fd6c0(0000) GS:ffff888126270000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fae828fa540 CR3: 0000000034006000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 f2fs_down_read fs/f2fs/f2fs.h:2395 [inline]
 f2fs_get_node_info+0x127/0x1ed0 fs/f2fs/node.c:584
 read_node_folio+0x221/0x410 fs/f2fs/node.c:1470
 __get_node_folio+0x3ca/0xdd0 fs/f2fs/node.c:1577
 f2fs_update_inode_page+0x83/0x2e0 fs/f2fs/inode.c:776
 f2fs_sync_inode_meta fs/f2fs/checkpoint.c:1354 [inline]
 block_operations fs/f2fs/checkpoint.c:1461 [inline]
 f2fs_write_checkpoint+0xbee/0x26a0 fs/f2fs/checkpoint.c:1876
 f2fs_issue_checkpoint+0x456/0x790 fs/f2fs/checkpoint.c:2096
 f2fs_do_shutdown+0x111/0x590 fs/f2fs/file.c:2460
 f2fs_ioc_shutdown fs/f2fs/file.c:2544 [inline]
 __f2fs_ioctl+0x4654/0xbdc0 fs/f2fs/file.c:4665
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl+0xff/0x170 fs/ioctl.c:583
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f73b47cce59
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f73b29fd028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f73b4a46090 RCX: 00007f73b47cce59
RDX: 0000200000000080 RSI: 000000008004587d RDI: 0000000000000005
RBP: 00007f73b4862d6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f73b4a46128 R14: 00007f73b4a46090 R15: 00007ffc10771078
 </TASK>