INFO: task syz-executor.0:5137 blocked for more than 143 seconds. Not tainted 6.3.0-rc6-syzkaller-00138-g44149752e998 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.0 state:D stack:20440 pid:5137 ppid:1 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5307 [inline] __schedule+0x173b/0x4630 kernel/sched/core.c:6625 schedule+0xc3/0x180 kernel/sched/core.c:6701 wb_wait_for_completion+0x166/0x290 fs/fs-writeback.c:192 sync_inodes_sb+0x297/0xab0 fs/fs-writeback.c:2727 sync_filesystem+0x16f/0x220 fs/sync.c:64 generic_shutdown_super+0x6f/0x340 fs/super.c:473 kill_block_super+0x7e/0xe0 fs/super.c:1407 deactivate_locked_super+0xa4/0x110 fs/super.c:331 cleanup_mnt+0x426/0x4c0 fs/namespace.c:1177 task_work_run+0x24a/0x300 kernel/task_work.c:179 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0xd9/0x100 kernel/entry/common.c:171 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:204 __syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline] syscall_exit_to_user_mode+0x64/0x280 kernel/entry/common.c:297 do_syscall_64+0x4d/0xc0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x466c67 RSP: 002b:00007fff3e995c38 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000466c67 RDX: 00007fff3e995d09 RSI: 0000000000000002 RDI: 00007fff3e995d00 RBP: 00007fff3e995d00 R08: 00000000ffffffff R09: 00007fff3e995ad0 R10: 0000000003438893 R11: 0000000000000246 R12: 00000000004ae4c5 R13: 00007fff3e996db0 R14: 0000000003438810 R15: 0000000000000002 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8cf25570 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xd20 kernel/rcu/tasks.h:510 1 lock held by rcu_tasks_trace/13: #0: ffffffff8cf25d70 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xd20 kernel/rcu/tasks.h:510 1 lock held by khungtaskd/28: #0: ffffffff8cf253a0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 2 locks held by kworker/u4:4/56: #0: ffff8880177f4138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x77e/0x10e0 kernel/workqueue.c:2363 #1: ffffc90001577d20 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x7c8/0x10e0 kernel/workqueue.c:2365 2 locks held by kworker/u4:6/1136: 2 locks held by getty/4743: #0: ffff88802ba4c098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:244 #1: ffffc900015902f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6ab/0x1db0 drivers/tty/n_tty.c:2177 2 locks held by syz-executor.0/5137: #0: ffff8880794ea0e0 (&type->s_umount_key#48){+.+.}-{3:3}, at: deactivate_super+0xad/0xf0 fs/super.c:361 #1: ffff888146dc27d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:364 [inline] #1: ffff888146dc27d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x278/0xab0 fs/fs-writeback.c:2725 1 lock held by segctord/5159: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 28 Comm: khungtaskd Not tainted 6.3.0-rc6-syzkaller-00138-g44149752e998 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/30/2023 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+0x270/0x300 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 5159 Comm: segctord Not tainted 6.3.0-rc6-syzkaller-00138-g44149752e998 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/30/2023 RIP: 0010:stack_trace_consume_entry+0xe6/0x280 kernel/stacktrace.c:93 Code: 89 f0 4c 8b 0c 24 4c 89 ee 48 ba 00 00 00 00 00 fc ff df 48 8b 1b 45 8d 70 01 41 0f b6 04 17 84 c0 0f 85 2d 01 00 00 45 89 31 <4a> 8d 1c c3 48 89 d8 48 c1 e8 03 80 3c 10 00 74 1a 4d 89 cf 48 89 RSP: 0018:ffffc9000500ef10 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffffc9000500f0e0 RCX: ffffffff8f92e000 RDX: dffffc0000000000 RSI: ffffffff81e0094f RDI: ffffc9000500f04c RBP: ffffc9000500f048 R08: 0000000000000000 R09: ffffc9000500f050 R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff92000a01e09 R13: 1ffff92000a01e09 R14: 0000000000000001 R15: 1ffff92000a01e0a FS: 0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005612f2e5ac20 CR3: 000000000cd30000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: arch_stack_walk+0x105/0x140 arch/x86/kernel/stacktrace.c:27 stack_trace_save+0x117/0x1c0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4f/0x70 mm/kasan/common.c:52 kasan_save_free_info+0x2b/0x40 mm/kasan/generic.c:521 ____kasan_slab_free+0xd6/0x120 mm/kasan/common.c:236 kasan_slab_free include/linux/kasan.h:162 [inline] slab_free_hook mm/slub.c:1781 [inline] slab_free_freelist_hook mm/slub.c:1807 [inline] slab_free mm/slub.c:3787 [inline] kmem_cache_free+0x297/0x520 mm/slub.c:3809 nilfs_btree_propagate+0xacb/0xde0 fs/nilfs2/btree.c:2101 nilfs_bmap_propagate+0x71/0x120 fs/nilfs2/bmap.c:337 nilfs_collect_dat_data+0x4d/0xc0 fs/nilfs2/segment.c:625 nilfs_segctor_apply_buffers+0x180/0x330 fs/nilfs2/segment.c:1020 nilfs_segctor_scan_file+0x76a/0xa10 fs/nilfs2/segment.c:1069 nilfs_segctor_collect_blocks fs/nilfs2/segment.c:1235 [inline] nilfs_segctor_collect fs/nilfs2/segment.c:1505 [inline] nilfs_segctor_do_construct+0x2254/0x6f70 fs/nilfs2/segment.c:2047 nilfs_segctor_construct+0x145/0x8c0 fs/nilfs2/segment.c:2381 nilfs_segctor_thread_construct fs/nilfs2/segment.c:2489 [inline] nilfs_segctor_thread+0x53a/0x1140 fs/nilfs2/segment.c:2572 kthread+0x270/0x300 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308