INFO: task kworker/u8:3:53 blocked for more than 143 seconds. Not tainted 6.13.0-rc6-next-20250107-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:3 state:D stack:21056 pid:53 tgid:53 ppid:2 flags:0x00004000 Workqueue: events_unbound netfs_write_collection_worker Call Trace: context_switch kernel/sched/core.c:5371 [inline] __schedule+0x18f6/0x4cd0 kernel/sched/core.c:6758 __schedule_loop kernel/sched/core.c:6835 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6850 bit_wait+0x12/0xd0 kernel/sched/wait_bit.c:237 __wait_on_bit+0xb0/0x2f0 kernel/sched/wait_bit.c:49 out_of_line_wait_on_bit+0x1d5/0x260 kernel/sched/wait_bit.c:64 wait_on_bit include/linux/wait_bit.h:77 [inline] netfs_retry_writes+0x16e/0x19b0 fs/netfs/write_retry.c:215 netfs_collect_write_results fs/netfs/write_collect.c:352 [inline] netfs_write_collection_worker+0x2f90/0x3bb0 fs/netfs/write_collect.c:374 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+0x7a9/0x920 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 INFO: task kworker/u8:12:6815 blocked for more than 145 seconds. Not tainted 6.13.0-rc6-next-20250107-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:12 state:D stack:20400 pid:6815 tgid:6815 ppid:2 flags:0x00004000 Workqueue: writeback wb_workfn (flush-9p-7) Call Trace: context_switch kernel/sched/core.c:5371 [inline] __schedule+0x18f6/0x4cd0 kernel/sched/core.c:6758 __schedule_loop kernel/sched/core.c:6835 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6850 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6907 __mutex_lock_common kernel/locking/mutex.c:662 [inline] __mutex_lock+0x817/0x1010 kernel/locking/mutex.c:730 netfs_writepages+0x12b/0x9e0 fs/netfs/write_issue.c:564 do_writepages+0x35f/0x880 mm/page-writeback.c:2683 __writeback_single_inode+0x14f/0x10d0 fs/fs-writeback.c:1680 writeback_sb_inodes+0x820/0x1360 fs/fs-writeback.c:1976 wb_writeback+0x413/0xb80 fs/fs-writeback.c:2156 wb_do_writeback fs/fs-writeback.c:2303 [inline] wb_workfn+0x410/0x1080 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+0x7a9/0x920 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 INFO: task syz.7.409:7927 blocked for more than 145 seconds. Not tainted 6.13.0-rc6-next-20250107-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.7.409 state:D stack:24088 pid:7927 tgid:7925 ppid:7379 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5371 [inline] __schedule+0x18f6/0x4cd0 kernel/sched/core.c:6758 __schedule_loop kernel/sched/core.c:6835 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6850 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6907 __mutex_lock_common kernel/locking/mutex.c:662 [inline] __mutex_lock+0x817/0x1010 kernel/locking/mutex.c:730 netfs_writepages+0x12b/0x9e0 fs/netfs/write_issue.c:564 do_writepages+0x35f/0x880 mm/page-writeback.c:2683 filemap_fdatawrite_wbc mm/filemap.c:389 [inline] __filemap_fdatawrite_range mm/filemap.c:422 [inline] __filemap_fdatawrite mm/filemap.c:428 [inline] filemap_fdatawrite+0x1f3/0x2a0 mm/filemap.c:433 v9fs_dir_release+0x151/0x560 fs/9p/vfs_dir.c:219 __fput+0x3e9/0x9f0 fs/file_table.c:450 task_work_run+0x24f/0x310 kernel/task_work.c:227 get_signal+0x15f7/0x1750 kernel/signal.c:2790 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0xce/0x340 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f4ece985d29 RSP: 002b:00007f4ecf6de038 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: 0000000000190000 RBX: 00007f4eceb75fa0 RCX: 00007f4ece985d29 RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000007 RBP: 00007f4ecea01b08 R08: 0000000000000000 R09: 0000000000000000 R10: 000000007ffff000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f4eceb75fa0 R15: 00007ffccc594fa8 INFO: task syz.7.409:7937 blocked for more than 145 seconds. Not tainted 6.13.0-rc6-next-20250107-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.7.409 state:D stack:26512 pid:7937 tgid:7925 ppid:7379 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5371 [inline] __schedule+0x18f6/0x4cd0 kernel/sched/core.c:6758 __schedule_loop kernel/sched/core.c:6835 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6850 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6907 __mutex_lock_common kernel/locking/mutex.c:662 [inline] __mutex_lock+0x817/0x1010 kernel/locking/mutex.c:730 netfs_writepages+0x12b/0x9e0 fs/netfs/write_issue.c:564 do_writepages+0x35f/0x880 mm/page-writeback.c:2683 filemap_fdatawrite_wbc mm/filemap.c:389 [inline] __filemap_fdatawrite_range mm/filemap.c:422 [inline] __filemap_fdatawrite mm/filemap.c:428 [inline] filemap_fdatawrite+0x1f3/0x2a0 mm/filemap.c:433 v9fs_vfs_setattr+0x7e5/0xe20 fs/9p/vfs_inode.c:1072 notify_change+0xbca/0xe90 fs/attr.c:552 vfs_utimes+0x4b5/0x770 fs/utimes.c:66 do_utimes_path fs/utimes.c:99 [inline] do_utimes fs/utimes.c:140 [inline] do_futimesat fs/utimes.c:194 [inline] __do_sys_utimes fs/utimes.c:207 [inline] __se_sys_utimes+0x194/0x380 fs/utimes.c:204 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: 0033:0x7f4ece985d29 RSP: 002b:00007f4ecc7d5038 EFLAGS: 00000246 ORIG_RAX: 00000000000000eb RAX: ffffffffffffffda RBX: 00007f4eceb76160 RCX: 00007f4ece985d29 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000180 RBP: 00007f4ecea01b08 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007f4eceb76160 R15: 00007ffccc594fa8 INFO: task syz.6.421:7980 blocked for more than 146 seconds. Not tainted 6.13.0-rc6-next-20250107-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.6.421 state:D stack:27488 pid:7980 tgid:7979 ppid:6597 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5371 [inline] __schedule+0x18f6/0x4cd0 kernel/sched/core.c:6758 __schedule_loop kernel/sched/core.c:6835 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6850 wb_wait_for_completion+0x166/0x290 fs/fs-writeback.c:216 sync_inodes_sb+0x28e/0xbd0 fs/fs-writeback.c:2824 iterate_supers+0xc6/0x190 fs/super.c:934 ksys_sync+0xbd/0x1c0 fs/sync.c:102 __do_sys_sync+0xe/0x20 fs/sync.c:113 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: 0033:0x7f16f1b85d29 RSP: 002b:00007f16f294c038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007f16f1d75fa0 RCX: 00007f16f1b85d29 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f16f1d75fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007f16f1d75fa0 R15: 00007fff63ac2f48 INFO: task syz.6.421:7983 blocked for more than 146 seconds. Not tainted 6.13.0-rc6-next-20250107-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.6.421 state:D stack:27488 pid:7983 tgid:7979 ppid:6597 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5371 [inline] __schedule+0x18f6/0x4cd0 kernel/sched/core.c:6758 __schedule_loop kernel/sched/core.c:6835 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6850 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6907 rwsem_down_write_slowpath+0xeee/0x13b0 kernel/locking/rwsem.c:1176 __down_write_common kernel/locking/rwsem.c:1304 [inline] __down_write kernel/locking/rwsem.c:1313 [inline] down_write+0x1d7/0x220 kernel/locking/rwsem.c:1578 bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline] sync_inodes_sb+0x26f/0xbd0 fs/fs-writeback.c:2822 iterate_supers+0xc6/0x190 fs/super.c:934 ksys_sync+0xbd/0x1c0 fs/sync.c:102 __do_sys_sync+0xe/0x20 fs/sync.c:113 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: 0033:0x7f16f1b85d29 RSP: 002b:00007f16f292b038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007f16f1d76080 RCX: 00007f16f1b85d29 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f16f1d76080 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f16f1d76080 R15: 00007fff63ac2f48 Showing all locks held in the system: 1 lock held by khungtaskd/30: #0: ffffffff8e937ee0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8e937ee0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8e937ee0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6746 2 locks held by kworker/u8:3/53: #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: ffffc90000bd7c60 ((work_completion)(&rreq->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc90000bd7c60 ((work_completion)(&rreq->work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1840 kernel/workqueue.c:3310 2 locks held by getty/5587: #0: ffff88814d93f0a0 (&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/u8:12/6815: #0: ffff888143ad9948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff888143ad9948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1840 kernel/workqueue.c:3310 #1: ffffc90003317c60 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc90003317c60 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1840 kernel/workqueue.c:3310 #2: ffff88807bb70500 (&ctx->wb_lock){+.+.}-{4:4}, at: netfs_writepages+0x12b/0x9e0 fs/netfs/write_issue.c:564 1 lock held by syz.7.409/7927: #0: ffff88807bb70500 (&ctx->wb_lock){+.+.}-{4:4}, at: netfs_writepages+0x12b/0x9e0 fs/netfs/write_issue.c:564 1 lock held by syz.7.409/7933: #0: ffff88807bb70500 (&ctx->wb_lock){+.+.}-{4:4}, at: netfs_writepages+0xcf/0x9e0 fs/netfs/write_issue.c:558 3 locks held by syz.7.409/7937: #0: ffff88804ae00420 (sb_writers#30){.+.+}-{0:0}, at: mnt_want_write+0x3f/0x90 fs/namespace.c:547 #1: ffff88807bb70148 (&sb->s_type->i_mutex_key#34){++++}-{4:4}, at: inode_lock include/linux/fs.h:865 [inline] #1: ffff88807bb70148 (&sb->s_type->i_mutex_key#34){++++}-{4:4}, at: vfs_utimes+0x44d/0x770 fs/utimes.c:65 #2: ffff88807bb70500 (&ctx->wb_lock){+.+.}-{4:4}, at: netfs_writepages+0x12b/0x9e0 fs/netfs/write_issue.c:564 2 locks held by syz.6.421/7980: #0: ffff88804ae000e0 (&type->s_umount_key#104){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff88804ae000e0 (&type->s_umount_key#104){++++}-{4:4}, at: super_lock+0x27c/0x400 fs/super.c:120 #1: ffff8880292587d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline] #1: ffff8880292587d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x26f/0xbd0 fs/fs-writeback.c:2822 2 locks held by syz.6.421/7983: #0: ffff88804ae000e0 (&type->s_umount_key#104){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff88804ae000e0 (&type->s_umount_key#104){++++}-{4:4}, at: super_lock+0x27c/0x400 fs/super.c:120 #1: ffff8880292587d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline] #1: ffff8880292587d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x26f/0xbd0 fs/fs-writeback.c:2822 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.13.0-rc6-next-20250107-syzkaller #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+0x7a9/0x920 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148 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 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline] NMI backtrace for cpu 0 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:106 [inline] NMI backtrace for cpu 0 skipped: idling at acpi_safe_halt+0x21/0x30 drivers/acpi/processor_idle.c:111