INFO: task kworker/u4:2:33 blocked for more than 143 seconds. Not tainted 6.4.0-rc5-syzkaller-00002-gf8dba31b0a82 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:2 state:D stack:24888 pid:33 ppid:2 flags:0x00004000 Workqueue: writeback wb_workfn (flush-7:5) Call Trace: context_switch kernel/sched/core.c:5343 [inline] __schedule+0x187b/0x4900 kernel/sched/core.c:6669 schedule+0xc3/0x180 kernel/sched/core.c:6745 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6804 __mutex_lock_common+0xe33/0x2530 kernel/locking/mutex.c:679 __mutex_lock kernel/locking/mutex.c:747 [inline] mutex_lock_nested+0x1b/0x20 kernel/locking/mutex.c:799 exfat_write_inode+0x69/0x120 fs/exfat/inode.c:93 write_inode fs/fs-writeback.c:1456 [inline] __writeback_single_inode+0x69b/0xfa0 fs/fs-writeback.c:1668 writeback_sb_inodes+0x8e3/0x11d0 fs/fs-writeback.c:1894 __writeback_inodes_wb+0x11b/0x260 fs/fs-writeback.c:1965 wb_writeback+0x46c/0xc70 fs/fs-writeback.c:2070 wb_check_background_flush fs/fs-writeback.c:2136 [inline] wb_do_writeback fs/fs-writeback.c:2224 [inline] wb_workfn+0xc6f/0xff0 fs/fs-writeback.c:2251 process_one_work+0x8a0/0x10e0 kernel/workqueue.c:2405 worker_thread+0xa63/0x1210 kernel/workqueue.c:2552 kthread+0x2b8/0x350 kernel/kthread.c:379 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 INFO: task kworker/u4:3:46 blocked for more than 144 seconds. Not tainted 6.4.0-rc5-syzkaller-00002-gf8dba31b0a82 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:3 state:D stack:24320 pid:46 ppid:2 flags:0x00004000 Workqueue: writeback wb_workfn (flush-7:3) Call Trace: context_switch kernel/sched/core.c:5343 [inline] __schedule+0x187b/0x4900 kernel/sched/core.c:6669 schedule+0xc3/0x180 kernel/sched/core.c:6745 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6804 __mutex_lock_common+0xe33/0x2530 kernel/locking/mutex.c:679 __mutex_lock kernel/locking/mutex.c:747 [inline] mutex_lock_nested+0x1b/0x20 kernel/locking/mutex.c:799 exfat_write_inode+0x69/0x120 fs/exfat/inode.c:93 write_inode fs/fs-writeback.c:1456 [inline] __writeback_single_inode+0x69b/0xfa0 fs/fs-writeback.c:1668 writeback_sb_inodes+0x8e3/0x11d0 fs/fs-writeback.c:1894 __writeback_inodes_wb+0x11b/0x260 fs/fs-writeback.c:1965 wb_writeback+0x46c/0xc70 fs/fs-writeback.c:2070 wb_check_background_flush fs/fs-writeback.c:2136 [inline] wb_do_writeback fs/fs-writeback.c:2224 [inline] wb_workfn+0xc6f/0xff0 fs/fs-writeback.c:2251 process_one_work+0x8a0/0x10e0 kernel/workqueue.c:2405 worker_thread+0xa63/0x1210 kernel/workqueue.c:2552 kthread+0x2b8/0x350 kernel/kthread.c:379 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 INFO: task kworker/u4:5:938 blocked for more than 145 seconds. Not tainted 6.4.0-rc5-syzkaller-00002-gf8dba31b0a82 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:5 state:D stack:21720 pid:938 ppid:2 flags:0x00004000 Workqueue: writeback wb_workfn (flush-7:2) Call Trace: context_switch kernel/sched/core.c:5343 [inline] __schedule+0x187b/0x4900 kernel/sched/core.c:6669 schedule+0xc3/0x180 kernel/sched/core.c:6745 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6804 __mutex_lock_common+0xe33/0x2530 kernel/locking/mutex.c:679 __mutex_lock kernel/locking/mutex.c:747 [inline] mutex_lock_nested+0x1b/0x20 kernel/locking/mutex.c:799 exfat_write_inode+0x69/0x120 fs/exfat/inode.c:93 write_inode fs/fs-writeback.c:1456 [inline] __writeback_single_inode+0x69b/0xfa0 fs/fs-writeback.c:1668 writeback_sb_inodes+0x8e3/0x11d0 fs/fs-writeback.c:1894 __writeback_inodes_wb+0x11b/0x260 fs/fs-writeback.c:1965 wb_writeback+0x46c/0xc70 fs/fs-writeback.c:2070 wb_check_background_flush fs/fs-writeback.c:2136 [inline] wb_do_writeback fs/fs-writeback.c:2224 [inline] wb_workfn+0xc6f/0xff0 fs/fs-writeback.c:2251 process_one_work+0x8a0/0x10e0 kernel/workqueue.c:2405 worker_thread+0xa63/0x1210 kernel/workqueue.c:2552 kthread+0x2b8/0x350 kernel/kthread.c:379 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 INFO: task kworker/u4:6:2423 blocked for more than 145 seconds. Not tainted 6.4.0-rc5-syzkaller-00002-gf8dba31b0a82 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:6 state:D stack:20672 pid:2423 ppid:2 flags:0x00004000 Workqueue: writeback wb_workfn (flush-7:0) Call Trace: context_switch kernel/sched/core.c:5343 [inline] __schedule+0x187b/0x4900 kernel/sched/core.c:6669 schedule+0xc3/0x180 kernel/sched/core.c:6745 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6804 __mutex_lock_common+0xe33/0x2530 kernel/locking/mutex.c:679 __mutex_lock kernel/locking/mutex.c:747 [inline] mutex_lock_nested+0x1b/0x20 kernel/locking/mutex.c:799 exfat_write_inode+0x69/0x120 fs/exfat/inode.c:93 write_inode fs/fs-writeback.c:1456 [inline] __writeback_single_inode+0x69b/0xfa0 fs/fs-writeback.c:1668 writeback_sb_inodes+0x8e3/0x11d0 fs/fs-writeback.c:1894 __writeback_inodes_wb+0x11b/0x260 fs/fs-writeback.c:1965 wb_writeback+0x46c/0xc70 fs/fs-writeback.c:2070 wb_check_background_flush fs/fs-writeback.c:2136 [inline] wb_do_writeback fs/fs-writeback.c:2224 [inline] wb_workfn+0xc6f/0xff0 fs/fs-writeback.c:2251 process_one_work+0x8a0/0x10e0 kernel/workqueue.c:2405 worker_thread+0xa63/0x1210 kernel/workqueue.c:2552 kthread+0x2b8/0x350 kernel/kthread.c:379 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 INFO: task kworker/u4:0:5044 blocked for more than 146 seconds. Not tainted 6.4.0-rc5-syzkaller-00002-gf8dba31b0a82 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:0 state:D stack:25120 pid:5044 ppid:2 flags:0x00004000 Workqueue: writeback wb_workfn (flush-7:1) Call Trace: context_switch kernel/sched/core.c:5343 [inline] __schedule+0x187b/0x4900 kernel/sched/core.c:6669 schedule+0xc3/0x180 kernel/sched/core.c:6745 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6804 __mutex_lock_common+0xe33/0x2530 kernel/locking/mutex.c:679 __mutex_lock kernel/locking/mutex.c:747 [inline] mutex_lock_nested+0x1b/0x20 kernel/locking/mutex.c:799 exfat_write_inode+0x69/0x120 fs/exfat/inode.c:93 write_inode fs/fs-writeback.c:1456 [inline] __writeback_single_inode+0x69b/0xfa0 fs/fs-writeback.c:1668 writeback_sb_inodes+0x8e3/0x11d0 fs/fs-writeback.c:1894 __writeback_inodes_wb+0x11b/0x260 fs/fs-writeback.c:1965 wb_writeback+0x46c/0xc70 fs/fs-writeback.c:2070 wb_check_background_flush fs/fs-writeback.c:2136 [inline] wb_do_writeback fs/fs-writeback.c:2224 [inline] wb_workfn+0xc6f/0xff0 fs/fs-writeback.c:2251 process_one_work+0x8a0/0x10e0 kernel/workqueue.c:2405 worker_thread+0xa63/0x1210 kernel/workqueue.c:2552 kthread+0x2b8/0x350 kernel/kthread.c:379 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 INFO: task kworker/u4:1:5045 blocked for more than 147 seconds. Not tainted 6.4.0-rc5-syzkaller-00002-gf8dba31b0a82 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:1 state:D stack:25120 pid:5045 ppid:2 flags:0x00004000 Workqueue: writeback wb_workfn (flush-7:4) Call Trace: context_switch kernel/sched/core.c:5343 [inline] __schedule+0x187b/0x4900 kernel/sched/core.c:6669 schedule+0xc3/0x180 kernel/sched/core.c:6745 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6804 __mutex_lock_common+0xe33/0x2530 kernel/locking/mutex.c:679 __mutex_lock kernel/locking/mutex.c:747 [inline] mutex_lock_nested+0x1b/0x20 kernel/locking/mutex.c:799 exfat_write_inode+0x69/0x120 fs/exfat/inode.c:93 write_inode fs/fs-writeback.c:1456 [inline] __writeback_single_inode+0x69b/0xfa0 fs/fs-writeback.c:1668 writeback_sb_inodes+0x8e3/0x11d0 fs/fs-writeback.c:1894 __writeback_inodes_wb+0x11b/0x260 fs/fs-writeback.c:1965 wb_writeback+0x46c/0xc70 fs/fs-writeback.c:2070 wb_check_background_flush fs/fs-writeback.c:2136 [inline] wb_do_writeback fs/fs-writeback.c:2224 [inline] wb_workfn+0xc6f/0xff0 fs/fs-writeback.c:2251 process_one_work+0x8a0/0x10e0 kernel/workqueue.c:2405 worker_thread+0xa63/0x1210 kernel/workqueue.c:2552 kthread+0x2b8/0x350 kernel/kthread.c:379 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/13: #0: ffffffff8cf276f0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xd20 kernel/rcu/tasks.h:518 1 lock held by rcu_tasks_trace/14: #0: ffffffff8cf27ab0 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xd20 kernel/rcu/tasks.h:518 1 lock held by khungtaskd/28: #0: ffffffff8cf27520 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 4 locks held by kworker/u4:2/33: #0: ffff888144e6d938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x77e/0x10e0 kernel/workqueue.c:2378 #1: ffffc90000a9fd20 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x7c8/0x10e0 kernel/workqueue.c:2380 #2: ffff88807c71c0e0 (&type->s_umount_key#43){.+.+}-{3:3}, at: trylock_super+0x1f/0xf0 fs/super.c:414 #3: ffff88807bc260e0 (&sbi->s_lock){+.+.}-{3:3}, at: exfat_write_inode+0x69/0x120 fs/exfat/inode.c:93 4 locks held by kworker/u4:3/46: #0: ffff888144e6d938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x77e/0x10e0 kernel/workqueue.c:2378 #1: ffffc90000b77d20 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x7c8/0x10e0 kernel/workqueue.c:2380 #2: ffff88807c71a0e0 (&type->s_umount_key#43){.+.+}-{3:3}, at: trylock_super+0x1f/0xf0 fs/super.c:414 #3: ffff8880771300e0 (&sbi->s_lock){+.+.}-{3:3}, at: exfat_write_inode+0x69/0x120 fs/exfat/inode.c:93 4 locks held by kworker/u4:5/938: #0: ffff888144e6d938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x77e/0x10e0 kernel/workqueue.c:2378 #1: ffffc9000485fd20 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x7c8/0x10e0 kernel/workqueue.c:2380 #2: ffff88807df220e0 (&type->s_umount_key#43){.+.+}-{3:3}, at: trylock_super+0x1f/0xf0 fs/super.c:414 #3: ffff888077ef20e0 (&sbi->s_lock){+.+.}-{3:3}, at: exfat_write_inode+0x69/0x120 fs/exfat/inode.c:93 4 locks held by kworker/u4:6/2423: #0: ffff888144e6d938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x77e/0x10e0 kernel/workqueue.c:2378 #1: ffffc9000ac8fd20 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x7c8/0x10e0 kernel/workqueue.c:2380 #2: ffff88807c7180e0 (&type->s_umount_key#43){.+.+}-{3:3}, at: trylock_super+0x1f/0xf0 fs/super.c:414 #3: ffff8880771340e0 (&sbi->s_lock){+.+.}-{3:3}, at: exfat_write_inode+0x69/0x120 fs/exfat/inode.c:93 2 locks held by getty/4747: #0: ffff88814ac7d098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900015902f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6ab/0x1db0 drivers/tty/n_tty.c:2176 6 locks held by syz-executor181/5034: 6 locks held by syz-executor181/5035: 6 locks held by syz-executor181/5036: 6 locks held by syz-executor181/5037: 6 locks held by syz-executor181/5038: 6 locks held by syz-executor181/5039: 4 locks held by kworker/u4:0/5044: #0: ffff888144e6d938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x77e/0x10e0 kernel/workqueue.c:2378 #1: ffffc90003b4fd20 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x7c8/0x10e0 kernel/workqueue.c:2380 #2: ffff88807c71e0e0 (&type->s_umount_key#43){.+.+}-{3:3}, at: trylock_super+0x1f/0xf0 fs/super.c:414 #3: ffff8880771520e0 (&sbi->s_lock){+.+.}-{3:3}, at: exfat_write_inode+0x69/0x120 fs/exfat/inode.c:93 4 locks held by kworker/u4:1/5045: #0: ffff888144e6d938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x77e/0x10e0 kernel/workqueue.c:2378 #1: ffffc90003b6fd20 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x7c8/0x10e0 kernel/workqueue.c:2380 #2: ffff8880790da0e0 (&type->s_umount_key#43){.+.+}-{3:3}, at: trylock_super+0x1f/0xf0 fs/super.c:414 #3: ffff88801926a0e0 (&sbi->s_lock){+.+.}-{3:3}, at: exfat_write_inode+0x69/0x120 fs/exfat/inode.c:93 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 28 Comm: khungtaskd Not tainted 6.4.0-rc5-syzkaller-00002-gf8dba31b0a82 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/25/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106 nmi_cpu_backtrace+0x498/0x4d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x187/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline] watchdog+0xec2/0xf00 kernel/hung_task.c:379 kthread+0x2b8/0x350 kernel/kthread.c:379 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 5038 Comm: syz-executor181 Not tainted 6.4.0-rc5-syzkaller-00002-gf8dba31b0a82 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/25/2023 RIP: 0010:__sanitizer_cov_trace_cmp4+0x80/0x90 kernel/kcov.c:279 Code: 8d 42 28 4c 39 c8 77 22 89 f8 89 f6 49 ff c2 4c 89 11 48 c7 44 0a 08 04 00 00 00 48 89 44 0a 10 48 89 74 0a 18 4c 89 44 0a 20 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 f3 0f 1e fa 4c 8b RSP: 0018:ffffc90003b2f898 EFLAGS: 00000293 RAX: 0000000000000000 RBX: 0000000000000001 RCX: 0000000000000009 RDX: ffff888017299dc0 RSI: 0000000000038c4c RDI: 0000000000038c4c RBP: ffffc90003b2f9b8 R08: ffffffff825d6982 R09: ffffed100e8b8ae9 R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000007 R13: 0000000038c4c682 R14: 0000000000038c4c R15: 0000000000038c4c FS: 0000555556b80300(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055fdad8d1680 CR3: 000000007d952000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __exfat_free_cluster+0x382/0x990 fs/exfat/fatent.c:187 exfat_free_cluster+0x77/0xd0 fs/exfat/fatent.c:232 __exfat_truncate+0x692/0x9b0 fs/exfat/file.c:184 exfat_evict_inode+0xd8/0x270 fs/exfat/inode.c:622 evict+0x2a4/0x620 fs/inode.c:665 __dentry_kill+0x436/0x650 fs/dcache.c:607 dentry_kill+0xbb/0x290 dput+0x1f3/0x420 fs/dcache.c:913 do_renameat2+0xd85/0x1660 fs/namei.c:5004 __do_sys_rename fs/namei.c:5048 [inline] __se_sys_rename fs/namei.c:5046 [inline] __x64_sys_rename+0x86/0x90 fs/namei.c:5046 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7fc36eb06aa9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 11 15 00 00 90 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 c0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fff7c065748 EFLAGS: 00000246 ORIG_RAX: 0000000000000052 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fc36eb06aa9 RDX: 0000000000000000 RSI: 0000000020000080 RDI: 0000000020000040 RBP: 0000000000000000 R08: 00007fff7c065770 R09: 00007fff7c065770 R10: 00007fff7c065620 R11: 0000000000000246 R12: 00007fc36eac58c0 R13: 00007fff7c0657a0 R14: 00007fff7c065780 R15: 0000000000000000 INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.037 msecs