INFO: task kworker/u8:2:35 blocked for more than 143 seconds. Not tainted 6.13.0-rc2-syzkaller-00362-g2d8308bf5b67 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:2 state:D stack:20664 pid:35 tgid:35 ppid:2 flags:0x00004000 Workqueue: writeback wb_workfn (flush-7:2) 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 __mutex_lock_common kernel/locking/mutex.c:665 [inline] __mutex_lock+0x7e7/0xee0 kernel/locking/mutex.c:735 exfat_write_inode+0xe5/0x1a0 fs/exfat/inode.c:108 write_inode fs/fs-writeback.c:1525 [inline] __writeback_single_inode+0x708/0x10d0 fs/fs-writeback.c:1745 writeback_sb_inodes+0x820/0x1360 fs/fs-writeback.c:1976 __writeback_inodes_wb+0x11b/0x260 fs/fs-writeback.c:2047 wb_writeback+0x427/0xb80 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+0xb94/0x1080 fs/fs-writeback.c:2343 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0xa66/0x1840 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: 2 locks held by kworker/u8:0/11: #0: ffff888021e9f948 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff888021e9f948 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1840 kernel/workqueue.c:3310 #1: ffffc90000107d00 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc90000107d00 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1840 kernel/workqueue.c:3310 1 lock held by khungtaskd/30: #0: ffffffff8e937ae0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8e937ae0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8e937ae0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6744 4 locks held by kworker/u8:2/35: #0: ffff888143ec4948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff888143ec4948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1840 kernel/workqueue.c:3310 #1: ffffc90000ab7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc90000ab7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1840 kernel/workqueue.c:3310 #2: ffff88806419a0e0 (&type->s_umount_key#80){++++}-{4:4}, at: super_trylock_shared+0x22/0xf0 fs/super.c:562 #3: ffff8880641980e8 (&sbi->s_lock#2){+.+.}-{4:4}, at: exfat_write_inode+0xe5/0x1a0 fs/exfat/inode.c:108 1 lock held by dhcpcd/5487: #0: ffffffff8fca04c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #0: ffffffff8fca04c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:326 [inline] #0: ffffffff8fca04c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0xbcb/0x2150 net/core/rtnetlink.c:4010 2 locks held by getty/5576: #0: ffff8880359890a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000361c2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x6a6/0x1e00 drivers/tty/n_tty.c:2211 3 locks held by kworker/0:4/5826: #0: ffff88801ac80948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff88801ac80948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1840 kernel/workqueue.c:3310 #1: ffffc9000412fd00 (deferred_process_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc9000412fd00 (deferred_process_work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1840 kernel/workqueue.c:3310 #2: ffffffff8fca04c8 (rtnl_mutex){+.+.}-{4:4}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104 5 locks held by kworker/u8:8/6607: #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/0x1840 kernel/workqueue.c:3310 #1: ffffc90004e07d00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc90004e07d00 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1840 kernel/workqueue.c:3310 #2: ffffffff8fc94010 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0x16a/0xd50 net/core/net_namespace.c:602 #3: ffffffff8fca04c8 (rtnl_mutex){+.+.}-{4:4}, at: default_device_exit_batch+0xe9/0xaa0 net/core/dev.c:12059 #4: ffffffff8e93cff8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:297 [inline] #4: ffffffff8e93cff8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x381/0x830 kernel/rcu/tree_exp.h:976 3 locks held by kworker/u8:9/8107: 2 locks held by syz-executor/9528: #0: ffffffff8f041728 (bio_slab_lock){+.+.}-{4:4}, at: bio_put_slab block/bio.c:140 [inline] #0: ffffffff8f041728 (bio_slab_lock){+.+.}-{4:4}, at: bioset_exit+0x42f/0x650 block/bio.c:1755 #1: ffffffff8e93cec0 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:4565 3 locks held by syz-executor/10899: 3 locks held by kworker/u8:25/13755: #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/0x1840 kernel/workqueue.c:3310 #1: ffffc90003a3fd00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc90003a3fd00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1840 kernel/workqueue.c:3310 #2: ffffffff8fca04c8 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:281 1 lock held by syz-executor/13964: #0: ffffffff8fca04c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #0: ffffffff8fca04c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:326 [inline] #0: ffffffff8fca04c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0xbcb/0x2150 net/core/rtnetlink.c:4010 2 locks held by syz.3.947/14333: #0: ffff88806419a0e0 (&type->s_umount_key#80){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff88806419a0e0 (&type->s_umount_key#80){++++}-{4:4}, at: super_lock+0x27c/0x400 fs/super.c:120 #1: ffff888143b627d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline] #1: ffff888143b627d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x26e/0xb50 fs/fs-writeback.c:2819 2 locks held by syz.3.947/14334: #0: ffff88806419a0e0 (&type->s_umount_key#80){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff88806419a0e0 (&type->s_umount_key#80){++++}-{4:4}, at: super_lock+0x27c/0x400 fs/super.c:120 #1: ffff888143b627d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline] #1: ffff888143b627d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x26e/0xb50 fs/fs-writeback.c:2819 2 locks held by syz.3.947/14336: #0: ffff88806419a0e0 (&type->s_umount_key#80){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff88806419a0e0 (&type->s_umount_key#80){++++}-{4:4}, at: super_lock+0x27c/0x400 fs/super.c:120 #1: ffff888143b627d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline] #1: ffff888143b627d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x26e/0xb50 fs/fs-writeback.c:2819 2 locks held by syz.9.953/14385: #0: ffff88806419a0e0 (&type->s_umount_key#80){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff88806419a0e0 (&type->s_umount_key#80){++++}-{4:4}, at: super_lock+0x27c/0x400 fs/super.c:120 #1: ffff888143b627d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline] #1: ffff888143b627d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x26e/0xb50 fs/fs-writeback.c:2819 1 lock held by syz-executor/14427: #0: ffffffff8fca04c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #0: ffffffff8fca04c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:326 [inline] #0: ffffffff8fca04c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0xbcb/0x2150 net/core/rtnetlink.c:4010 1 lock held by syz-executor/14468: #0: ffffffff8fca04c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:128 [inline] #0: ffffffff8fca04c8 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x47e/0x1bd0 net/ipv4/devinet.c:987 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.13.0-rc2-syzkaller-00362-g2d8308bf5b67 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/25/2024 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:234 [inline] watchdog+0xff6/0x1040 kernel/hung_task.c:397 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: 8107 Comm: kworker/u8:9 Not tainted 6.13.0-rc2-syzkaller-00362-g2d8308bf5b67 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/25/2024 Workqueue: bat_events batadv_nc_worker RIP: 0010:__lock_acquire+0x304/0x2100 kernel/locking/lockdep.c:5159 Code: 0a 00 00 83 fa 31 48 89 7c 24 08 0f 83 59 1a 00 00 4c 8d 2c 92 4a 8d 5c ef 20 48 89 d8 48 c1 e8 03 48 89 44 24 18 0f b6 04 30 <84> c0 0f 85 ca 14 00 00 4c 8b a4 24 d0 00 00 00 b8 00 e0 ff ff 23 RSP: 0018:ffffc9000b16f8f0 EFLAGS: 00000802 RAX: 0000000000000000 RBX: ffff88802d1e4750 RCX: ffffffff9a377903 RDX: 0000000000000002 RSI: dffffc0000000000 RDI: ffff88802d1e46e0 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: dffffc0000000000 R11: fffffbfff20309df R12: ffff88802d1e3c00 R13: 000000000000000a R14: 0000000000000021 R15: ffffffff8e937ae0 FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f49341b4000 CR3: 000000000e736000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849 rcu_lock_acquire include/linux/rcupdate.h:337 [inline] rcu_read_lock include/linux/rcupdate.h:849 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline] batadv_nc_worker+0xec/0x610 net/batman-adv/network-coding.c:719 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0xa66/0x1840 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