INFO: task kworker/u8:4:76 blocked for more than 143 seconds. Not tainted 6.13.0-rc1-syzkaller-00001-ge70140ba0d2b #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:4 state:D stack:20984 pid:76 tgid:76 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: ffffffff8e937aa0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8e937aa0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8e937aa0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6744 4 locks held by kworker/u8:4/76: #0: ffff888143ec1148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff888143ec1148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1840 kernel/workqueue.c:3310 #1: ffffc9000217fd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc9000217fd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1840 kernel/workqueue.c:3310 #2: ffff88805778e0e0 (&type->s_umount_key#49){++++}-{4:4}, at: super_trylock_shared+0x22/0xf0 fs/super.c:562 #3: ffff88805778c0e8 (&sbi->s_lock){+.+.}-{4:4}, at: exfat_write_inode+0xe5/0x1a0 fs/exfat/inode.c:108 5 locks held by kworker/u8:7/1163: #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: ffffc90004b5fd00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc90004b5fd00 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1840 kernel/workqueue.c:3310 #2: ffffffff8fc90c50 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0x16a/0xcc0 net/core/net_namespace.c:586 #3: ffffffff8fc9d0c8 (rtnl_mutex){+.+.}-{4:4}, at: default_device_exit_batch+0xe9/0xaa0 net/core/dev.c:12053 #4: ffffffff8e93cfb8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:297 [inline] #4: ffffffff8e93cfb8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x381/0x830 kernel/rcu/tree_exp.h:976 1 lock held by dhcpcd/5489: #0: ffffffff8fc9d0c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:128 [inline] #0: ffffffff8fc9d0c8 (rtnl_mutex){+.+.}-{4:4}, at: devinet_ioctl+0x31a/0x1ac0 net/ipv4/devinet.c:1129 2 locks held by getty/5578: #0: ffff8880360ea0a0 (&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 3 locks held by kworker/1:4/5877: #0: ffff88801ac81948 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff88801ac81948 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1840 kernel/workqueue.c:3310 #1: ffffc90003d27d00 ((reg_check_chans).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc90003d27d00 ((reg_check_chans).work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1840 kernel/workqueue.c:3310 #2: ffffffff8fc9d0c8 (rtnl_mutex){+.+.}-{4:4}, at: reg_check_chans_work+0x99/0xfb0 net/wireless/reg.c:2480 3 locks held by syz.4.5/5958: 3 locks held by kworker/u8:9/6772: #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: ffffc90003337d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc90003337d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1840 kernel/workqueue.c:3310 #2: ffffffff8fc9d0c8 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:276 1 lock held by syz-executor/7474: #0: ffffffff8fc9d0c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #0: ffffffff8fc9d0c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnetlink_rcv_msg+0x6e6/0xcf0 net/core/rtnetlink.c:6923 4 locks held by syz.5.187/7552: #0: ffff888148c901b0 (&bdev->bd_fsfreeze_mutex){+.+.}-{4:4}, at: bdev_freeze+0x2a/0x220 block/bdev.c:248 #1: ffff888034992420 (sb_writers#21){++++}-{0:0}, at: sb_wait_write fs/super.c:1910 [inline] #1: ffff888034992420 (sb_writers#21){++++}-{0:0}, at: freeze_super+0x4e9/0xee0 fs/super.c:2099 #2: ffff8880349920e0 (&type->s_umount_key#73){+.+.}-{4:4}, at: __super_lock fs/super.c:56 [inline] #2: ffff8880349920e0 (&type->s_umount_key#73){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline] #2: ffff8880349920e0 (&type->s_umount_key#73){+.+.}-{4:4}, at: freeze_super+0x4f1/0xee0 fs/super.c:2100 #3: ffff888034992518 (sb_pagefaults#3){+.+.}-{0:0}, at: sb_wait_write fs/super.c:1910 [inline] #3: ffff888034992518 (sb_pagefaults#3){+.+.}-{0:0}, at: freeze_super+0x519/0xee0 fs/super.c:2104 4 locks held by syz.7.188/7507: #0: ffff88805a400278 (&c->state_lock){+.+.}-{4:4}, at: bch2_fs_start+0x45/0x5b0 fs/bcachefs/super.c:1007 #1: ffff88805a404398 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:158 [inline] #1: ffff88805a404398 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:249 [inline] #1: ffff88805a404398 (&c->btree_trans_barrier){.+.+}-{0:0}, at: __bch2_trans_get+0x7e1/0xd30 fs/bcachefs/btree_iter.c:3228 #2: ffff888028618128 (bcachefs_btree){+.+.}-{0:0}, at: trans_set_locked fs/bcachefs/btree_locking.h:194 [inline] #2: ffff888028618128 (bcachefs_btree){+.+.}-{0:0}, at: bch2_trans_begin+0x9b0/0x1bf0 fs/bcachefs/btree_iter.c:3125 #3: ffff88805a4049d0 (&c->mark_lock){++++}-{0:0}, at: bch2_accounting_read+0x277c/0x4ee0 fs/bcachefs/disk_accounting.c:750 1 lock held by udevadm/7555: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.13.0-rc1-syzkaller-00001-ge70140ba0d2b #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: 5958 Comm: syz.4.5 Not tainted 6.13.0-rc1-syzkaller-00001-ge70140ba0d2b #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:bytes_is_nonzero mm/kasan/generic.c:86 [inline] RIP: 0010:memory_is_nonzero mm/kasan/generic.c:104 [inline] RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:129 [inline] RIP: 0010:memory_is_poisoned mm/kasan/generic.c:161 [inline] RIP: 0010:check_region_inline mm/kasan/generic.c:180 [inline] RIP: 0010:kasan_check_range+0x79/0x290 mm/kasan/generic.c:189 Code: 4d 89 c1 49 c1 e9 03 49 be 01 00 00 00 00 fc ff df 4f 8d 3c 31 4c 89 fd 4c 29 dd 48 83 fd 10 7f 29 48 85 ed 0f 84 3e 01 00 00 <4c> 89 cd 48 f7 d5 48 01 dd 41 80 3b 00 0f 85 c9 01 00 00 49 ff c3 RSP: 0018:ffffc900045cf5b8 EFLAGS: 00000002 RAX: 0000000000000001 RBX: 1ffffffff2850512 RCX: ffffffff817b241a RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff94282890 RBP: 0000000000000001 R08: ffffffff94282897 R09: 1ffffffff2850512 R10: dffffc0000000000 R11: fffffbfff2850512 R12: ffff8880283346c4 R13: dffffc0000000000 R14: dffffc0000000001 R15: fffffbfff2850513 FS: 00007f94665f66c0(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fdd98363360 CR3: 0000000034e20000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: instrument_atomic_read include/linux/instrumented.h:68 [inline] _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline] hlock_class kernel/locking/lockdep.c:228 [inline] mark_lock+0x9a/0x360 kernel/locking/lockdep.c:4727 mark_usage kernel/locking/lockdep.c:4670 [inline] __lock_acquire+0xc3e/0x2100 kernel/locking/lockdep.c:5180 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849 fs_reclaim_acquire+0xaf/0x130 mm/page_alloc.c:3868 might_alloc include/linux/sched/mm.h:318 [inline] bdev_getblk+0x3d/0x550 fs/buffer.c:1427 __bread_gfp+0x86/0x400 fs/buffer.c:1485 sb_bread include/linux/buffer_head.h:346 [inline] __exfat_ent_get fs/exfat/fatent.c:48 [inline] exfat_ent_get+0x14d/0x400 fs/exfat/fatent.c:97 __exfat_free_cluster+0x56f/0x990 fs/exfat/fatent.c:200 exfat_free_cluster+0x77/0xd0 fs/exfat/fatent.c:232 __exfat_truncate+0x745/0xa60 fs/exfat/file.c:235 exfat_evict_inode+0xd8/0x270 fs/exfat/inode.c:683 evict+0x4e8/0x9a0 fs/inode.c:796 do_unlinkat+0x512/0x830 fs/namei.c:4594 __do_sys_unlink fs/namei.c:4635 [inline] __se_sys_unlink fs/namei.c:4633 [inline] __x64_sys_unlink+0x47/0x50 fs/namei.c:4633 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: 0033:0x7f946877ff19 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f94665f6058 EFLAGS: 00000246 ORIG_RAX: 0000000000000057 RAX: ffffffffffffffda RBX: 00007f9468946080 RCX: 00007f946877ff19 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000200001c0 RBP: 00007f94687f3986 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f9468946080 R15: 00007ffc392ec678