INFO: task kworker/u8:26:1661 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:26   state:D stack:20168 pid:1661  tgid:1661  ppid:2      task_flags:0x4208060 flags:0x00080000
Workqueue: writeback wb_workfn (flush-7:0)
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5325 [inline]
 __schedule+0x16f3/0x4c20 kernel/sched/core.c:6929
 __schedule_loop kernel/sched/core.c:7011 [inline]
 rt_mutex_schedule+0x77/0xf0 kernel/sched/core.c:7307
 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline]
 __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline]
 __rt_mutex_slowlock_locked+0x1e04/0x25e0 kernel/locking/rtmutex.c:1760
 rt_mutex_slowlock+0xb5/0x160 kernel/locking/rtmutex.c:1800
 __rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline]
 rwbase_write_lock+0x14f/0x750 kernel/locking/rwbase_rt.c:244
 f2fs_down_write fs/f2fs/f2fs.h:2294 [inline]
 f2fs_issue_checkpoint+0x3a8/0x610 fs/f2fs/checkpoint.c:1893
 f2fs_balance_fs_bg+0x54b/0x9c0 fs/f2fs/segment.c:544
 f2fs_write_node_pages+0x146/0x6e0 fs/f2fs/node.c:2218
 do_writepages+0x32e/0x550 mm/page-writeback.c:2598
 __writeback_single_inode+0x143/0x12e0 fs/fs-writeback.c:1737
 writeback_sb_inodes+0x8c8/0x1860 fs/fs-writeback.c:2030
 __writeback_inodes_wb+0x111/0x240 fs/fs-writeback.c:2107
 wb_writeback+0x44f/0xaf0 fs/fs-writeback.c:2218
 wb_check_old_data_flush fs/fs-writeback.c:2322 [inline]
 wb_do_writeback fs/fs-writeback.c:2375 [inline]
 wb_workfn+0xaf4/0xf00 fs/fs-writeback.c:2403
 process_one_work kernel/workqueue.c:3263 [inline]
 process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x4bc/0x870 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:
1 lock held by khungtaskd/38:
 #0: ffffffff8d5a9e80 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8d5a9e80 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
 #0: ffffffff8d5a9e80 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
5 locks held by kworker/u8:6/1028:
 #0: ffff888019ad4938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline]
 #0: ffff888019ad4938 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346
 #1: ffffc900049f7ba0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline]
 #1: ffffc900049f7ba0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346
 #2: ffffffff8e856700 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x7b0 net/core/net_namespace.c:669
 #3: ffffffff8e8635f8 (rtnl_mutex){+.+.}-{4:4}, at: ieee80211_unregister_hw+0x55/0x2c0 net/mac80211/main.c:1674
 #4: ffff88804f3508b8 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: class_wiphy_constructor include/net/cfg80211.h:6358 [inline]
 #4: ffff88804f3508b8 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: ieee80211_stop+0x126/0x240 net/mac80211/iface.c:817
3 locks held by kworker/u8:24/1659:
 #0: ffff888019fe7138 ((wq_completion)cfg80211){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline]
 #0: ffff888019fe7138 ((wq_completion)cfg80211){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346
 #1: ffffc90006017ba0 ((work_completion)(&(&rdev->dfs_update_channels_wk)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline]
 #1: ffffc90006017ba0 ((work_completion)(&(&rdev->dfs_update_channels_wk)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346
 #2: ffffffff8e8635f8 (rtnl_mutex){+.+.}-{4:4}, at: cfg80211_dfs_channels_update_work+0xc4/0x650 net/wireless/mlme.c:1040
4 locks held by kworker/u8:26/1661:
 #0: ffff88814046a938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline]
 #0: ffff88814046a938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346
 #1: ffffc90006057ba0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline]
 #1: ffffc90006057ba0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346
 #2: ffff8880584340d0 (&type->s_umount_key#57){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:563
 #3: ffff88802f2399f8 (&sbi->gc_lock){+.+.}-{4:4}, at: f2fs_down_write fs/f2fs/f2fs.h:2294 [inline]
 #3: ffff88802f2399f8 (&sbi->gc_lock){+.+.}-{4:4}, at: f2fs_issue_checkpoint+0x3a8/0x610 fs/f2fs/checkpoint.c:1893
1 lock held by udevd/5192:
3 locks held by dhcpcd/5486:
1 lock held by dhcpcd/5487:
2 locks held by getty/5584:
 #0: ffff88823bf348a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc90003e832e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x444/0x1400 drivers/tty/n_tty.c:2222
2 locks held by kworker/1:4/5891:
2 locks held by kworker/u8:0/7949:
 #0: ffff88813ff69938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline]
 #0: ffff88813ff69938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346
 #1: ffffc90000127ba0 ((reaper_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline]
 #1: ffffc90000127ba0 ((reaper_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346
6 locks held by syz.0.180/9189:
1 lock held by syz-executor/9469:
1 lock held by udevd/9502:
3 locks held by udevd/9761:
2 locks held by udevd/9871:
3 locks held by kworker/u8:2/9998:
 #0: ffff88813ff69938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline]
 #0: ffff88813ff69938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346
 #1: ffffc90005cb7ba0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline]
 #1: ffffc90005cb7ba0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346
 #2: ffffffff8e8635f8 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303
2 locks held by kworker/u8:3/10387:
 #0: ffff88813ff69938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline]
 #0: ffff88813ff69938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346
 #1: ffffc90006797ba0 (connector_reaper_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline]
 #1: ffffc90006797ba0 (connector_reaper_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346
2 locks held by syz-executor/10642:
 #0: ffffffff8ed65b10 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8ed65b10 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
 #0: ffffffff8ed65b10 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570
 #1: ffffffff8e8635f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
 #1: ffffffff8e8635f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
 #1: ffffffff8e8635f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8e9/0x1c80 net/core/rtnetlink.c:4064
2 locks held by syz.8.307/10740:
2 locks held by syz.7.305/10742:
 #0: ffff88802728e0d0 (&type->s_umount_key#62/1){+.+.}-{4:4}, at: alloc_super+0x28c/0xac0 fs/super.c:344
 #1: ffffffff8d452ad8 (wq_pool_mutex){+.+.}-{4:4}, at: apply_wqattrs_lock kernel/workqueue.c:5211 [inline]
 #1: ffffffff8d452ad8 (wq_pool_mutex){+.+.}-{4:4}, at: __alloc_workqueue+0x9f4/0x1b70 kernel/workqueue.c:5766
1 lock held by syz.9.309/10756:

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

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 10/25/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:332 [inline]
 watchdog+0xf60/0xfa0 kernel/hung_task.c:495
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x4bc/0x870 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: 9502 Comm: udevd Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:__lock_acquire+0xad3/0xd20 kernel/locking/lockdep.c:5245
Code: 01 00 00 4c 89 f6 89 ea 4c 89 f9 e8 27 38 00 00 85 c0 0f 84 e4 01 00 00 41 f6 46 22 10 75 2e 48 8b 1c 24 4c 89 bb 50 0b 00 00 <8b> 83 58 0b 00 00 ff c0 89 83 58 0b 00 00 83 f8 30 0f 83 64 01 00
RSP: 0018:ffffc9000153f0c8 EFLAGS: 00000046
RAX: 0000000000000001 RBX: ffff88802d7bda00 RCX: b3bd79b652d62600
RDX: 0000000000000000 RSI: ffff88802d7be588 RDI: ffff88802d7bda00
RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff81736c15
R10: ffffc9000153f318 R11: ffffffff81ab27c0 R12: 00000000f0bc35c7
R13: ffff88802d7be560 R14: ffff88802d7be588 R15: f5b5b5699bd644f3
FS:  00007f7a078f5880(0000) GS:ffff888126ee9000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f7a06fa8000 CR3: 0000000068f62000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
 rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 rcu_read_lock include/linux/rcupdate.h:867 [inline]
 class_rcu_constructor include/linux/rcupdate.h:1195 [inline]
 unwind_next_frame+0xc2/0x2390 arch/x86/kernel/unwind_orc.c:479
 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:56 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:77
 unpoison_slab_object mm/kasan/common.c:342 [inline]
 __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:368
 kasan_slab_alloc include/linux/kasan.h:252 [inline]
 slab_post_alloc_hook mm/slub.c:4978 [inline]
 slab_alloc_node mm/slub.c:5288 [inline]
 kmem_cache_alloc_noprof+0x181/0x6b0 mm/slub.c:5295
 mt_alloc_one lib/maple_tree.c:174 [inline]
 mas_alloc_nodes+0x291/0x350 lib/maple_tree.c:1110
 mas_preallocate+0x2e0/0x670 lib/maple_tree.c:5194
 vma_iter_prealloc mm/vma.h:442 [inline]
 commit_merge+0x1fa/0x620 mm/vma.c:753
 vma_merge_existing_range mm/vma.c:973 [inline]
 vma_modify+0xf2d/0x1880 mm/vma.c:1608
 vma_modify_flags+0x1e8/0x230 mm/vma.c:1649
 mprotect_fixup+0x407/0x9c0 mm/mprotect.c:816
 do_mprotect_pkey+0x8c5/0xcd0 mm/mprotect.c:990
 __do_sys_mprotect mm/mprotect.c:1011 [inline]
 __se_sys_mprotect mm/mprotect.c:1008 [inline]
 __x64_sys_mprotect+0x80/0x90 mm/mprotect.c:1008
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f7a07a59fe7
Code: ef e8 3d fa ff ff 84 c0 75 b9 31 db 48 83 c4 08 48 89 d8 5b 5d 41 5c 41 5d 41 5e 41 5f c3 0f 1f 44 00 00 b8 0a 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d e1 2d 0d 00 f7 d8 64 89 01 48
RSP: 002b:00007ffe422fa678 EFLAGS: 00000246 ORIG_RAX: 000000000000000a
RAX: ffffffffffffffda RBX: 0000000000000200 RCX: 00007f7a07a59fe7
RDX: 0000000000000001 RSI: 0000000000000200 RDI: 00007f7a06fa8000
RBP: 00005649254be050 R08: 0000000000000000 R09: 0000000000000200
R10: 00005649254be0b0 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000001000 R14: 00005649254c1398 R15: 00007f7a0813939c
 </TASK>