INFO: task kworker/u8:11:6189 blocked for more than 143 seconds. Not tainted 6.13.0-rc4-syzkaller-00054-gd6ef8b40d075 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:11 state:D stack:14648 pid:6189 tgid:6189 ppid:2 flags:0x00004000 Workqueue: writeback wb_workfn (flush-7:6) 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_background_flush fs/fs-writeback.c:2228 [inline] wb_do_writeback fs/fs-writeback.c:2316 [inline] wb_workfn+0xc4b/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: 4 locks held by kworker/u8:1/12: #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: ffffc90000117d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc90000117d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1840 kernel/workqueue.c:3310 #2: ffffffff8fca0788 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:281 #3: ffffffff8e93cff8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:297 [inline] #3: ffffffff8e93cff8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x381/0x830 kernel/rcu/tree_exp.h:976 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 3 locks held by kworker/u8:6/1169: #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: ffff8880b8628948 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x41d/0x7a0 kernel/sched/psi.c:987 #2: ffff8880b862a718 (&base->lock){-.-.}-{2:2}, at: __mod_timer+0x744/0xeb0 kernel/time/timer.c:1163 1 lock held by dhcpcd/5487: #0: ffffffff8fca0788 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:128 [inline] #0: ffffffff8fca0788 (rtnl_mutex){+.+.}-{4:4}, at: devinet_ioctl+0x31a/0x1ac0 net/ipv4/devinet.c:1129 2 locks held by getty/5572: #0: ffff888034da00a0 (&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 6 locks held by kworker/u8:9/6186: #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: ffffc9000543fd00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc9000543fd00 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1840 kernel/workqueue.c:3310 #2: ffffffff8fc942d0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0x16a/0xd50 net/core/net_namespace.c:602 #3: ffff88805de310e8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1014 [inline] #3: ffff88805de310e8 (&dev->mutex){....}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:108 [inline] #3: ffff88805de310e8 (&dev->mutex){....}-{4:4}, at: devlink_pernet_pre_exit+0x13b/0x440 net/devlink/core.c:506 #4: ffff888022fca250 (&devlink->lock_key#35){+.+.}-{4:4}, at: devl_lock net/devlink/core.c:276 [inline] #4: ffff888022fca250 (&devlink->lock_key#35){+.+.}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:109 [inline] #4: ffff888022fca250 (&devlink->lock_key#35){+.+.}-{4:4}, at: devlink_pernet_pre_exit+0x14d/0x440 net/devlink/core.c:506 #5: ffffffff8e93cec0 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:4565 4 locks held by kworker/u8:11/6189: #0: ffff8881446b5148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff8881446b5148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1840 kernel/workqueue.c:3310 #1: ffffc90005787d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1840 kernel/workqueue.c:3310 #2: ffff88807994e0e0 (&type->s_umount_key#115){++++}-{4:4}, at: super_trylock_shared+0x22/0xf0 fs/super.c:562 #3: ffff8880122700e8 (&sbi->s_lock#2){+.+.}-{4:4}, at: exfat_write_inode+0xe5/0x1a0 fs/exfat/inode.c:108 2 locks held by syz-executor/16671: #0: ffff8880641e80e0 (&type->s_umount_key#68){++++}-{4:4}, at: __super_lock fs/super.c:56 [inline] #0: ffff8880641e80e0 (&type->s_umount_key#68){++++}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff8880641e80e0 (&type->s_umount_key#68){++++}-{4:4}, at: deactivate_super+0xb5/0xf0 fs/super.c:505 #1: ffffffff8e93cec0 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:4565 3 locks held by syz-executor/16790: 1 lock held by syz-executor/17707: #0: ffffffff8fca0788 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:698 [inline] #0: ffffffff8fca0788 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3b/0x1b0 drivers/net/tun.c:3517 1 lock held by syz.1.1338/19829: #0: ffffffff8e93cff8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:329 [inline] #0: ffffffff8e93cff8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x451/0x830 kernel/rcu/tree_exp.h:976 2 locks held by syz.7.1340/19836: #0: ffff88807994e0e0 (&type->s_umount_key#115){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff88807994e0e0 (&type->s_umount_key#115){++++}-{4:4}, at: super_lock+0x27c/0x400 fs/super.c:120 #1: ffff88802523a7d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline] #1: ffff88802523a7d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x26e/0xb50 fs/fs-writeback.c:2819 2 locks held by syz.7.1340/19837: #0: ffff88807994e0e0 (&type->s_umount_key#115){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff88807994e0e0 (&type->s_umount_key#115){++++}-{4:4}, at: super_lock+0x27c/0x400 fs/super.c:120 #1: ffff88802523a7d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline] #1: ffff88802523a7d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x26e/0xb50 fs/fs-writeback.c:2819 2 locks held by syz.7.1340/19839: #0: ffff88807994e0e0 (&type->s_umount_key#115){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff88807994e0e0 (&type->s_umount_key#115){++++}-{4:4}, at: super_lock+0x27c/0x400 fs/super.c:120 #1: ffff88802523a7d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline] #1: ffff88802523a7d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x26e/0xb50 fs/fs-writeback.c:2819 2 locks held by syz.7.1340/19840: #0: ffff88807994e0e0 (&type->s_umount_key#115){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff88807994e0e0 (&type->s_umount_key#115){++++}-{4:4}, at: super_lock+0x27c/0x400 fs/super.c:120 #1: ffff88802523a7d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline] #1: ffff88802523a7d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x26e/0xb50 fs/fs-writeback.c:2819 2 locks held by syz.7.1340/19841: #0: ffff88807994e0e0 (&type->s_umount_key#115){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff88807994e0e0 (&type->s_umount_key#115){++++}-{4:4}, at: super_lock+0x27c/0x400 fs/super.c:120 #1: ffff88802523a7d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline] #1: ffff88802523a7d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x26e/0xb50 fs/fs-writeback.c:2819 2 locks held by syz.7.1340/19842: #0: ffff88807994e0e0 (&type->s_umount_key#115){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff88807994e0e0 (&type->s_umount_key#115){++++}-{4:4}, at: super_lock+0x27c/0x400 fs/super.c:120 #1: ffff88802523a7d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline] #1: ffff88802523a7d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x26e/0xb50 fs/fs-writeback.c:2819 2 locks held by syz.7.1340/19843: #0: ffff88807994e0e0 (&type->s_umount_key#115){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff88807994e0e0 (&type->s_umount_key#115){++++}-{4:4}, at: super_lock+0x27c/0x400 fs/super.c:120 #1: ffff88802523a7d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline] #1: ffff88802523a7d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x26e/0xb50 fs/fs-writeback.c:2819 2 locks held by syz.7.1340/19845: #0: ffff88807994e0e0 (&type->s_umount_key#115){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff88807994e0e0 (&type->s_umount_key#115){++++}-{4:4}, at: super_lock+0x27c/0x400 fs/super.c:120 #1: ffff88802523a7d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline] #1: ffff88802523a7d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x26e/0xb50 fs/fs-writeback.c:2819 1 lock held by syz-executor/19881: #0: ffffffff8fca0788 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:128 [inline] #0: ffffffff8fca0788 (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-rc4-syzkaller-00054-gd6ef8b40d075 #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: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: 16790 Comm: syz-executor Not tainted 6.13.0-rc4-syzkaller-00054-gd6ef8b40d075 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:__sanitizer_cov_trace_const_cmp8+0x7d/0x90 kernel/kcov.c:323 Code: c1 e1 05 48 8d 41 28 4c 39 c8 77 1e 49 ff c2 4c 89 12 48 c7 44 11 08 07 00 00 00 48 89 7c 11 10 48 89 74 11 18 4c 89 44 11 20 cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 90 90 90 RSP: 0018:ffffc9000ba5f468 EFLAGS: 00000293 RAX: 0000000000000000 RBX: 00fff00000004124 RCX: ffff88802d965a00 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000040000 R08: ffffffff81dc1247 R09: 1ffffd400024bff0 R10: dffffc0000000000 R11: fffff9400024bff1 R12: dffffc0000000000 R13: ffffea000125ff80 R14: ffffea000125ff88 R15: 1ffffd400024bff1 FS: 000055558a51d500(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffd8014ddb8 CR3: 000000006c406000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: constant_test_bit arch/x86/include/asm/bitops.h:206 [inline] arch_test_bit arch/x86/include/asm/bitops.h:238 [inline] _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:142 [inline] folio_test_unevictable include/linux/page-flags.h:589 [inline] folio_mark_accessed+0x127/0x9c0 mm/swap.c:437 __find_get_block+0x58a/0x1150 fs/buffer.c:1402 bdev_getblk+0x33/0x670 fs/buffer.c:1425 __bread_gfp+0x86/0x400 fs/buffer.c:1485 sb_bread include/linux/buffer_head.h:346 [inline] exfat_get_dentry+0x53b/0x730 fs/exfat/dir.c:672 exfat_readdir fs/exfat/dir.c:118 [inline] exfat_iterate+0x9f9/0x2ce0 fs/exfat/dir.c:242 wrap_directory_iterator+0x91/0xd0 fs/readdir.c:65 iterate_dir+0x571/0x800 fs/readdir.c:108 __do_sys_getdents64 fs/readdir.c:403 [inline] __se_sys_getdents64+0x1e2/0x4b0 fs/readdir.c:389 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7efcc15b8693 Code: c1 66 0f 1f 44 00 00 48 83 c4 08 48 89 ef 5b 5d e9 82 3e f8 ff 66 90 b8 ff ff ff 7f 48 39 c2 48 0f 47 d0 b8 d9 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 05 c3 0f 1f 40 00 48 c7 c2 a8 ff ff ff f7 d8 RSP: 002b:00007ffe0f202e18 EFLAGS: 00000293 ORIG_RAX: 00000000000000d9 RAX: ffffffffffffffda RBX: 000055558a538600 RCX: 00007efcc15b8693 RDX: 0000000000008000 RSI: 000055558a538600 RDI: 0000000000000005 RBP: 000055558a5385d4 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000001000 R11: 0000000000000293 R12: ffffffffffffffa8 R13: 0000000000000010 R14: 000055558a5385d0 R15: 0000000000000004