INFO: task kworker/u8:6:1153 blocked for more than 143 seconds. Not tainted 6.12.0-syzkaller-09073-g9f16d5e6f220 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:6 state:D stack:20848 pid:1153 tgid:1153 ppid:2 flags:0x00004000 Workqueue: writeback wb_workfn (flush-7:9) Call Trace: context_switch kernel/sched/core.c:5369 [inline] __schedule+0x17fb/0x4be0 kernel/sched/core.c:6756 __schedule_loop kernel/sched/core.c:6833 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6848 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6905 rwsem_down_write_slowpath+0xeee/0x13b0 kernel/locking/rwsem.c:1176 __down_write_common kernel/locking/rwsem.c:1304 [inline] __down_write kernel/locking/rwsem.c:1313 [inline] down_write+0x1d7/0x220 kernel/locking/rwsem.c:1578 f2fs_down_write fs/f2fs/f2fs.h:2199 [inline] f2fs_balance_fs+0x5b0/0x7a0 fs/f2fs/segment.c:448 f2fs_write_inode+0x3a7/0x4d0 fs/f2fs/inode.c:787 write_inode fs/fs-writeback.c:1525 [inline] __writeback_single_inode+0x711/0x10d0 fs/fs-writeback.c:1745 writeback_sb_inodes+0x80c/0x1370 fs/fs-writeback.c:1976 __writeback_inodes_wb+0x11b/0x260 fs/fs-writeback.c:2047 wb_writeback+0x427/0xbc0 fs/fs-writeback.c:2158 wb_check_old_data_flush fs/fs-writeback.c:2262 [inline] wb_do_writeback fs/fs-writeback.c:2315 [inline] wb_workfn+0xba1/0x1090 fs/fs-writeback.c:2343 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0xa63/0x1850 kernel/workqueue.c:3310 worker_thread+0x870/0xd30 kernel/workqueue.c:3391 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Showing all locks held in the system: 1 lock held by pool_workqueue_/3: #0: ffffffff8e941ab8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:329 [inline] #0: ffffffff8e941ab8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x451/0x830 kernel/rcu/tree_exp.h:976 1 lock held by khungtaskd/30: #0: ffffffff8e93c520 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8e93c520 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8e93c520 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6744 3 locks held by kworker/u8:5/748: #0: ffff8881456dd148 ((wq_completion)cfg80211){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff8881456dd148 ((wq_completion)cfg80211){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310 #1: ffffc90003677d00 ((work_completion)(&(&rdev->dfs_update_channels_wk)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc90003677d00 ((work_completion)(&(&rdev->dfs_update_channels_wk)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310 #2: ffffffff8fcd6e48 (rtnl_mutex){+.+.}-{4:4}, at: cfg80211_dfs_channels_update_work+0xbf/0x610 net/wireless/mlme.c:1015 4 locks held by kworker/u8:6/1153: #0: ffff8880212a3148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff8880212a3148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310 #1: ffffc9000400fd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc9000400fd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310 #2: ffff8880604c40e0 (&type->s_umount_key#78){++++}-{4:4}, at: super_trylock_shared+0x22/0xf0 fs/super.c:562 #3: ffff88805f1b9350 (&sbi->gc_lock){+.+.}-{4:4}, at: f2fs_down_write fs/f2fs/f2fs.h:2199 [inline] #3: ffff88805f1b9350 (&sbi->gc_lock){+.+.}-{4:4}, at: f2fs_balance_fs+0x5b0/0x7a0 fs/f2fs/segment.c:448 3 locks held by kworker/u8:7/3443: #0: ffff88801ac89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff88801ac89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310 #1: ffffc9000c647d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc9000c647d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310 #2: ffffffff8fcd6e48 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:276 6 locks held by kworker/u8:8/3502: #0: ffff88801baeb148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff88801baeb148 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310 #1: ffffc9000ca37d00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc9000ca37d00 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310 #2: ffffffff8fcca310 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0x16a/0xcc0 net/core/net_namespace.c:586 #3: ffffffff8fcd6e48 (rtnl_mutex){+.+.}-{4:4}, at: ieee80211_unregister_hw+0x55/0x2c0 net/mac80211/main.c:1664 #4: ffff888067bb8768 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: wiphy_lock include/net/cfg80211.h:6019 [inline] #4: ffff888067bb8768 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: ieee80211_stop+0x3e9/0x4a0 net/mac80211/iface.c:783 #5: ffffffff8e941ab8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:329 [inline] #5: ffffffff8e941ab8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x451/0x830 kernel/rcu/tree_exp.h:976 1 lock held by dhcpcd/5507: #0: ffffffff8fcd6e48 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:128 [inline] #0: ffffffff8fcd6e48 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_deladdr+0x1a1/0x7b0 net/ipv4/devinet.c:679 2 locks held by getty/5595: #0: ffff888035b520a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90002fde2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x6a6/0x1e00 drivers/tty/n_tty.c:2211 2 locks held by kworker/u8:9/6297: #0: ffff88801ac89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff88801ac89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310 #1: ffffc90003067d00 ((reaper_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc90003067d00 ((reaper_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310 1 lock held by syz-executor/8020: #0: ffffffff8e941ab8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:329 [inline] #0: ffffffff8e941ab8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x451/0x830 kernel/rcu/tree_exp.h:976 3 locks held by kworker/u8:10/8928: #0: ffff88814d53c948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff88814d53c948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310 #1: ffffc9000b78fd00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc9000b78fd00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310 #2: ffffffff8fcd6e48 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0xd0/0x16f0 net/ipv6/addrconf.c:4196 5 locks held by syz.9.321/9119: 2 locks held by syz.2.386/9673: #0: ffff8880604c40e0 (&type->s_umount_key#78){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff8880604c40e0 (&type->s_umount_key#78){++++}-{4:4}, at: super_lock+0x27c/0x400 fs/super.c:120 #1: ffff8881447a87d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline] #1: ffff8881447a87d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x26e/0xb50 fs/fs-writeback.c:2819 1 lock held by syz-executor/10807: #0: ffffffff8fcd6e48 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:128 [inline] #0: ffffffff8fcd6e48 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x47e/0x1bd0 net/ipv4/devinet.c:987 1 lock held by syz.9.534/11269: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.12.0-syzkaller-09073-g9f16d5e6f220 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline] watchdog+0xff4/0x1040 kernel/hung_task.c:379 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 24 Comm: ksoftirqd/1 Not tainted 6.12.0-syzkaller-09073-g9f16d5e6f220 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:unwind_next_frame+0x15/0x22d0 arch/x86/kernel/unwind_orc.c:469 Code: bb 00 eb 87 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 55 41 57 41 56 41 55 41 54 53 48 81 ec 98 00 00 00 <49> 89 fd 49 bc 00 00 00 00 00 fc ff df 48 8d 5f 48 48 89 d8 48 c1 RSP: 0018:ffffc900001e74f0 EFLAGS: 00000286 RAX: 0000000000000001 RBX: ffffc900001e75c0 RCX: ffffffff917cc000 RDX: dffffc0000000000 RSI: ffffffff81fd60c9 RDI: ffffc900001e75c0 RBP: ffffc900001e7650 R08: 0000000000000002 R09: ffffc900001e76b0 R10: ffffc900001e7610 R11: ffffffff81819e40 R12: ffff88801d680000 R13: ffffffff81819e40 R14: ffffc900001e76a0 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000555576e975c8 CR3: 000000007c270000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x118/0x1d0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:579 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x59/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2342 [inline] slab_free mm/slub.c:4579 [inline] kfree+0x1a0/0x440 mm/slub.c:4727 slab_free_after_rcu_debug+0x62/0x290 mm/slub.c:4616 rcu_do_batch kernel/rcu/tree.c:2567 [inline] rcu_core+0xaaa/0x17a0 kernel/rcu/tree.c:2823 handle_softirqs+0x2c5/0x980 kernel/softirq.c:554 run_ksoftirqd+0xca/0x130 kernel/softirq.c:943 smpboot_thread_fn+0x544/0xa30 kernel/smpboot.c:164 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244