INFO: task kworker/u4:5:1032 blocked for more than 143 seconds. Not tainted 6.14.0-rc1-syzkaller-g0de63bb7d919 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:5 state:D stack:19128 pid:1032 tgid:1032 ppid:2 task_flags:0x4208060 flags:0x00004000 Workqueue: events_unbound netfs_write_collection_worker Call Trace: context_switch kernel/sched/core.c:5377 [inline] __schedule+0x190e/0x4c90 kernel/sched/core.c:6764 __schedule_loop kernel/sched/core.c:6841 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6856 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:3236 [inline] process_scheduled_works+0xa66/0x1840 kernel/workqueue.c:3317 worker_thread+0x870/0xd30 kernel/workqueue.c:3398 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 Showing all locks held in the system: 2 locks held by kworker/u4:1/12: #0: ffff88801ac79148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff88801ac79148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1840 kernel/workqueue.c:3317 #1: ffffc900001e7c60 ((work_completion)(&rreq->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc900001e7c60 ((work_completion)(&rreq->work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1840 kernel/workqueue.c:3317 1 lock held by khungtaskd/25: #0: ffffffff8e9387e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8e9387e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8e9387e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6746 2 locks held by kworker/u4:5/1032: #0: ffff88801ac79148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff88801ac79148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1840 kernel/workqueue.c:3317 #1: ffffc900024bfc60 ((work_completion)(&rreq->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc900024bfc60 ((work_completion)(&rreq->work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1840 kernel/workqueue.c:3317 2 locks held by kworker/u4:9/1044: #0: ffff88801ac79148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff88801ac79148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1840 kernel/workqueue.c:3317 #1: ffffc9000254fc60 ((work_completion)(&rreq->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc9000254fc60 ((work_completion)(&rreq->work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1840 kernel/workqueue.c:3317 2 locks held by kworker/u4:10/1048: #0: ffff88801ac79148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff88801ac79148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1840 kernel/workqueue.c:3317 #1: ffffc9000257fc60 ((work_completion)(&rreq->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc9000257fc60 ((work_completion)(&rreq->work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1840 kernel/workqueue.c:3317 2 locks held by kworker/u4:12/3055: #0: ffff88801ac79148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff88801ac79148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1840 kernel/workqueue.c:3317 #1: ffffc9000da1fc60 ((work_completion)(&rreq->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc9000da1fc60 ((work_completion)(&rreq->work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1840 kernel/workqueue.c:3317 2 locks held by getty/5104: #0: ffff88801ce890a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000019b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x6a6/0x1e00 drivers/tty/n_tty.c:2211 3 locks held by syz.0.15/5886: #0: ffff888033b11d38 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x254/0x320 fs/file.c:1192 #1: ffff888043ade420 (sb_writers#13){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3023 [inline] #1: ffff888043ade420 (sb_writers#13){.+.+}-{0:0}, at: vfs_write+0x225/0xd10 fs/read_write.c:675 #2: ffff888000af0500 (&ctx->wb_lock){+.+.}-{4:4}, at: netfs_writepages+0xcf/0x9e0 fs/netfs/write_issue.c:558 3 locks held by syz.1.19/5918: #0: ffff88801f489d38 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x254/0x320 fs/file.c:1192 #1: ffff8880346a4420 (sb_writers#13){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3023 [inline] #1: ffff8880346a4420 (sb_writers#13){.+.+}-{0:0}, at: vfs_write+0x225/0xd10 fs/read_write.c:675 #2: ffff888000af1ec0 (&ctx->wb_lock){+.+.}-{4:4}, at: netfs_writepages+0xcf/0x9e0 fs/netfs/write_issue.c:558 3 locks held by syz.2.31/5966: #0: ffff888058ab8ef8 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x254/0x320 fs/file.c:1192 #1: ffff888058a42420 (sb_writers#13){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3023 [inline] #1: ffff888058a42420 (sb_writers#13){.+.+}-{0:0}, at: vfs_write+0x225/0xd10 fs/read_write.c:675 #2: ffff888000af58b0 (&ctx->wb_lock){+.+.}-{4:4}, at: netfs_writepages+0xcf/0x9e0 fs/netfs/write_issue.c:558 3 locks held by syz.3.36/6000: #0: ffff888040d47d38 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x254/0x320 fs/file.c:1192 #1: ffff888012a44420 (sb_writers#13){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3023 [inline] #1: ffff888012a44420 (sb_writers#13){.+.+}-{0:0}, at: vfs_write+0x225/0xd10 fs/read_write.c:675 #2: ffff888000af3880 (&ctx->wb_lock){+.+.}-{4:4}, at: netfs_writepages+0xcf/0x9e0 fs/netfs/write_issue.c:558 3 locks held by syz.4.72/6102: #0: ffff88801eddf9b8 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x254/0x320 fs/file.c:1192 #1: ffff888000faa420 (sb_writers#13){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3023 [inline] #1: ffff888000faa420 (sb_writers#13){.+.+}-{0:0}, at: vfs_write+0x225/0xd10 fs/read_write.c:675 #2: ffff888000af2ba0 (&ctx->wb_lock){+.+.}-{4:4}, at: netfs_writepages+0xcf/0x9e0 fs/netfs/write_issue.c:558 1 lock held by syz.5.210/6420: #0: ffff888012232288 (&ima_iint_mutex_key[depth]){+.+.}-{4:4}, at: ima_check_last_writer security/integrity/ima/ima_main.c:166 [inline] #0: ffff888012232288 (&ima_iint_mutex_key[depth]){+.+.}-{4:4}, at: ima_file_free+0x17f/0x4d0 security/integrity/ima/ima_main.c:205 1 lock held by syz-executor/6422: #0: ffffffff8e93dcb8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:302 [inline] #0: ffffffff8e93dcb8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x381/0x830 kernel/rcu/tree_exp.h:996 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 25 Comm: khungtaskd Not tainted 6.14.0-rc1-syzkaller-g0de63bb7d919 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 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:236 [inline] watchdog+0x1058/0x10a0 kernel/hung_task.c:399 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