INFO: task syz-executor.1:22258 blocked for more than 143 seconds. Not tainted 6.4.0-syzkaller-01554-g6f612579be9d #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.1 state:D stack:21072 pid:22258 ppid:10202 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x187b/0x4900 kernel/sched/core.c:6707 schedule+0xc3/0x180 kernel/sched/core.c:6783 wb_wait_for_completion+0x166/0x290 fs/fs-writeback.c:192 sync_inodes_sb+0x297/0xab0 fs/fs-writeback.c:2730 sync_filesystem+0x16f/0x220 fs/sync.c:64 generic_shutdown_super+0x6f/0x340 fs/super.c:473 kill_block_super+0x68/0xa0 fs/super.c:1418 deactivate_locked_super+0xa4/0x110 fs/super.c:331 cleanup_mnt+0x426/0x4c0 fs/namespace.c:1254 task_work_run+0x24a/0x300 kernel/task_work.c:179 exit_task_work include/linux/task_work.h:38 [inline] do_exit+0x68f/0x2290 kernel/exit.c:874 do_group_exit+0x206/0x2c0 kernel/exit.c:1024 get_signal+0x1709/0x17e0 kernel/signal.c:2876 arch_do_signal_or_restart+0x91/0x670 arch/x86/kernel/signal.c:308 exit_to_user_mode_loop+0x6a/0x100 kernel/entry/common.c:168 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:204 irqentry_exit_to_user_mode+0x9/0x40 kernel/entry/common.c:310 exc_page_fault+0x71e/0x910 arch/x86/mm/fault.c:1593 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:570 RIP: 0033:0x3ff318bce8 RSP: 002b:0000000020000298 EFLAGS: 00010217 RAX: 0000000000000000 RBX: 00007fe2cf9abf80 RCX: 00007fe2cf88c389 RDX: 00000000200001c0 RSI: 0000000020000290 RDI: 0000000000100000 RBP: 00007fe2cf8d7493 R08: 0000000020000300 R09: 0000000020000300 R10: 00000000200002c0 R11: 0000000000000206 R12: 0000000000000000 R13: 00007fff3ce4243f R14: 00007fe2d06ac300 R15: 0000000000022000 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/13: #0: ffffffff8cf272b0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xd20 kernel/rcu/tasks.h:522 1 lock held by rcu_tasks_trace/14: #0: ffffffff8cf27670 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xd20 kernel/rcu/tasks.h:522 1 lock held by khungtaskd/28: #0: ffffffff8cf270e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 2 locks held by getty/4748: #0: ffff88802cd02098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900015a02f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6b1/0x1db0 drivers/tty/n_tty.c:2176 2 locks held by kworker/1:6/5086: 3 locks held by kworker/0:7/5087: #0: ffff88802803dd38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x77e/0x10e0 kernel/workqueue.c:2381 #1: ffffc9000443fd20 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7c8/0x10e0 kernel/workqueue.c:2383 #2: ffffffff8e0a6688 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xd0/0x16b0 net/ipv6/addrconf.c:4088 4 locks held by kworker/u4:1/13774: #0: ffff888012aee138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x77e/0x10e0 kernel/workqueue.c:2381 #1: ffffc9000a70fd20 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x7c8/0x10e0 kernel/workqueue.c:2383 #2: ffff8880b983bfd8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:558 #3: ffffffff8cf270e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x40 include/linux/rcupdate.h:301 3 locks held by kworker/u4:12/15153: 2 locks held by kworker/0:0/17419: #0: ffff888012472538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x77e/0x10e0 kernel/workqueue.c:2381 #1: ffffc9000bd2fd20 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x7c8/0x10e0 kernel/workqueue.c:2383 2 locks held by syz-executor.1/22258: #0: ffff888020bbe0e0 (&type->s_umount_key#56){++++}-{3:3}, at: deactivate_super+0xad/0xf0 fs/super.c:361 #1: ffff8881417027d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:364 [inline] #1: ffff8881417027d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x278/0xab0 fs/fs-writeback.c:2728 2 locks held by syz-executor.1/25755: #0: ffffffff8e0a6688 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline] #0: ffffffff8e0a6688 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7ce/0xf40 net/core/rtnetlink.c:6414 #1: ffffffff8cf2c778 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:293 [inline] #1: ffffffff8cf2c778 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3a3/0x890 kernel/rcu/tree_exp.h:992 1 lock held by syz-executor.2/25791: #0: ffff88808a614000 (&sb->s_type->i_mutex_key#7){++++}-{3:3}, at: inode_lock_shared include/linux/fs.h:781 [inline] #0: ffff88808a614000 (&sb->s_type->i_mutex_key#7){++++}-{3:3}, at: ext4_dio_read_iter fs/ext4/file.c:78 [inline] #0: ffff88808a614000 (&sb->s_type->i_mutex_key#7){++++}-{3:3}, at: ext4_file_read_iter+0x297/0x670 fs/ext4/file.c:145 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 28 Comm: khungtaskd Not tainted 6.4.0-syzkaller-01554-g6f612579be9d #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106 nmi_cpu_SeaBIOS (version 1.8.2-google)