INFO: task kworker/u8:5:80 blocked for more than 143 seconds. Not tainted 6.13.0-rc4-syzkaller-00012-g9b2ffa6148b1 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:5 state:D stack:16944 pid:80 tgid:80 ppid:2 flags:0x00004000 Workqueue: writeback wb_workfn (flush-7:4) 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: 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/u8:4/70: #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: ffffc9000213fd00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc9000213fd00 (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: ffffffff8fca0788 (rtnl_mutex){+.+.}-{4:4}, at: wg_destruct+0x25/0x2e0 drivers/net/wireguard/device.c:246 4 locks held by kworker/u8:5/80: #0: ffff8881416b9148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff8881416b9148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1840 kernel/workqueue.c:3310 #1: ffffc9000214fd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc9000214fd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1840 kernel/workqueue.c:3310 #2: ffff888053ab20e0 (&type->s_umount_key#53){++++}-{4:4}, at: super_trylock_shared+0x22/0xf0 fs/super.c:562 #3: ffff888053ab00e8 (&sbi->s_lock){+.+.}-{4:4}, at: exfat_write_inode+0xe5/0x1a0 fs/exfat/inode.c:108 3 locks held by kworker/u8:6/1144: #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: ffffc90003f4fd00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc90003f4fd00 ((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 2 locks held by kworker/u8:7/1158: #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: ffffc9000404fd00 (connector_reaper_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc9000404fd00 (connector_reaper_work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1840 kernel/workqueue.c:3310 2 locks held by kworker/u8:8/3443: #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/0x1840 kernel/workqueue.c:3310 #1: ffffc9000c467d00 ((reaper_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc9000c467d00 ((reaper_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1840 kernel/workqueue.c:3310 1 lock held by dhcpcd/5488: #0: ffffffff8fca0788 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #0: ffffffff8fca0788 (rtnl_mutex){+.+.}-{4:4}, at: rtnetlink_rcv_msg+0x6e6/0xcf0 net/core/rtnetlink.c:6928 2 locks held by getty/5580: #0: ffff8880319ab0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x6a6/0x1e00 drivers/tty/n_tty.c:2211 4 locks held by syz-executor/5827: 1 lock held by syz-executor/6975: #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 4 locks held by syz-executor/7395: #0: ffffffff8f041868 (bio_slab_lock){+.+.}-{4:4}, at: bio_put_slab block/bio.c:140 [inline] #0: ffffffff8f041868 (bio_slab_lock){+.+.}-{4:4}, at: bioset_exit+0x42f/0x650 block/bio.c:1755 #1: ffffffff8e7d2ed0 (cpu_hotplug_lock){++++}-{0:0}, at: kmem_cache_destroy+0x3e/0x160 mm/slab_common.c:515 #2: ffffffff8ea1f590 (slab_mutex){+.+.}-{4:4}, at: kmem_cache_destroy+0x4c/0x160 mm/slab_common.c:516 #3: ffffffff8ea3b188 (flush_lock){+.+.}-{4:4}, at: flush_all_cpus_locked+0x20/0x170 mm/slub.c:3330 8 locks held by syz-executor/8163: #0: ffff888030d44420 (sb_writers#8){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2964 [inline] #0: ffff888030d44420 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x225/0xd30 fs/read_write.c:675 #1: ffff8881453bf888 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1ea/0x500 fs/kernfs/file.c:325 #2: ffff888144b0f698 (kn->active#49){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x20e/0x500 fs/kernfs/file.c:326 #3: ffffffff8f54c3e8 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xfc/0x480 drivers/net/netdevsim/bus.c:216 #4: ffff88807ed3c0e8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1014 [inline] #4: ffff88807ed3c0e8 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1095 [inline] #4: ffff88807ed3c0e8 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xce/0x7c0 drivers/base/dd.c:1293 #5: ffff88807ed3d250 (&devlink->lock_key#5){+.+.}-{4:4}, at: nsim_drv_remove+0x50/0x160 drivers/net/netdevsim/dev.c:1675 #6: ffffffff8fca0788 (rtnl_mutex){+.+.}-{4:4}, at: nsim_destroy+0x71/0x5c0 drivers/net/netdevsim/netdev.c:816 #7: ffffffff8e93cff8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:297 [inline] #7: ffffffff8e93cff8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x381/0x830 kernel/rcu/tree_exp.h:976 1 lock held by syz.3.248/8360: #0: ffffffff8f041868 (bio_slab_lock){+.+.}-{4:4}, at: bio_put_slab block/bio.c:140 [inline] #0: ffffffff8f041868 (bio_slab_lock){+.+.}-{4:4}, at: bioset_exit+0x42f/0x650 block/bio.c:1755 2 locks held by syz-executor/8384: #0: ffffffff8fc942d0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x328/0x570 net/core/net_namespace.c:512 #1: ffffffff8fca0788 (rtnl_mutex){+.+.}-{4:4}, at: wg_netns_pre_exit+0x1f/0x1e0 drivers/net/wireguard/device.c:415 1 lock held by syz-executor/8452: #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 1 CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.13.0-rc4-syzkaller-00012-g9b2ffa6148b1 #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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 5827 Comm: syz-executor Not tainted 6.13.0-rc4-syzkaller-00012-g9b2ffa6148b1 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:__lock_acquire+0xca6/0x2100 kernel/locking/lockdep.c:5196 Code: 89 d8 48 c1 e8 06 48 8d 3c c5 80 08 27 94 be 08 00 00 00 e8 7c 91 88 00 48 bf 00 00 00 00 00 fc ff df 48 0f a3 1d fa 46 ac 12 <0f> 83 66 09 00 00 49 8d 9d d0 0a 00 00 48 89 d8 48 c1 e8 03 48 89 RSP: 0018:ffffc90003fe7390 EFLAGS: 00000057 RAX: 0000000000000001 RBX: 00000000000000a2 RCX: ffffffff817ac174 RDX: 0000000000000000 RSI: 0000000000000008 RDI: dffffc0000000000 RBP: ffff888033946558 R08: ffffffff94270897 R09: 1ffffffff284e112 R10: dffffc0000000000 R11: fffffbfff284e113 R12: ffff8880339464c4 R13: ffff888033945a00 R14: 0000000000000000 R15: ffff888033946578 FS: 0000555593ec6500(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f7d16c2f5e8 CR3: 000000005f41c000 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 fs_reclaim_acquire+0xaf/0x130 mm/page_alloc.c:3870 might_alloc include/linux/sched/mm.h:318 [inline] bdev_getblk+0x3d/0x670 fs/buffer.c:1427 __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: 0033:0x7f43473b8693 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:00007ffe37213cc8 EFLAGS: 00000293 ORIG_RAX: 00000000000000d9 RAX: ffffffffffffffda RBX: 0000555593ee1600 RCX: 00007f43473b8693 RDX: 0000000000008000 RSI: 0000555593ee1600 RDI: 0000000000000005 RBP: 0000555593ee15d4 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000001000 R11: 0000000000000293 R12: ffffffffffffffa8 R13: 0000000000000010 R14: 0000555593ee15d0 R15: 0000000000000015