INFO: task syz-executor:6243 blocked for more than 143 seconds. Not tainted 6.16.0-rc3-next-20250627-syzkaller #0 Blocked by coredump. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:21704 pid:6243 tgid:6243 ppid:1 task_flags:0x40014c flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5313 [inline] __schedule+0x16f5/0x4d00 kernel/sched/core.c:6696 __schedule_loop kernel/sched/core.c:6774 [inline] schedule+0x165/0x360 kernel/sched/core.c:6789 wb_wait_for_completion+0x15f/0x260 fs/fs-writeback.c:216 sync_inodes_sb+0x1bb/0xa10 fs/fs-writeback.c:2833 sync_filesystem+0x17a/0x230 fs/sync.c:64 generic_shutdown_super+0x6f/0x2c0 fs/super.c:622 kill_block_super+0x44/0x90 fs/super.c:1755 deactivate_locked_super+0xb9/0x130 fs/super.c:474 cleanup_mnt+0x425/0x4c0 fs/namespace.c:1417 task_work_run+0x1d4/0x260 kernel/task_work.c:227 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x6b5/0x2300 kernel/exit.c:959 do_group_exit+0x21c/0x2d0 kernel/exit.c:1100 __do_sys_exit_group kernel/exit.c:1111 [inline] __se_sys_exit_group kernel/exit.c:1109 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1109 x64_sys_call+0x21ba/0x21c0 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fbc8518e929 RSP: 002b:00007fffa03eba78 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 00007fbc852109a9 RCX: 00007fbc8518e929 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001 RBP: 0000000000000027 R08: 00007fffa03e9816 R09: 00007fffa03ecd30 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fffa03ecd30 R13: 00007fbc85210925 R14: 000055558596d4a8 R15: 00007fffa03eeef0 INFO: task syz.0.83:6297 blocked for more than 144 seconds. Not tainted 6.16.0-rc3-next-20250627-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.83 state:D stack:21320 pid:6297 tgid:6296 ppid:5835 task_flags:0x400140 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5313 [inline] __schedule+0x16f5/0x4d00 kernel/sched/core.c:6696 __schedule_loop kernel/sched/core.c:6774 [inline] schedule+0x165/0x360 kernel/sched/core.c:6789 schedule_timeout+0x9a/0x270 kernel/time/sleep_timeout.c:75 ___down_common kernel/locking/semaphore.c:268 [inline] __down_common+0x319/0x6a0 kernel/locking/semaphore.c:293 down+0x80/0xd0 kernel/locking/semaphore.c:100 bch2_run_recovery_passes+0x177/0x210 fs/bcachefs/recovery_passes.c:609 bch2_fs_recovery+0x28c9/0x3a50 fs/bcachefs/recovery.c:1039 bch2_fs_start+0xa99/0xd90 fs/bcachefs/super.c:1211 bch2_fs_get_tree+0xafc/0x14f0 fs/bcachefs/fs.c:2490 vfs_get_tree+0x8f/0x2b0 fs/super.c:1804 do_new_mount+0x24a/0xa40 fs/namespace.c:3902 do_mount fs/namespace.c:4239 [inline] __do_sys_mount fs/namespace.c:4450 [inline] __se_sys_mount+0x317/0x410 fs/namespace.c:4427 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe12e9900ca RSP: 002b:00007fe12f720e68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007fe12f720ef0 RCX: 00007fe12e9900ca RDX: 00002000000058c0 RSI: 0000200000005900 RDI: 00007fe12f720eb0 RBP: 00002000000058c0 R08: 00007fe12f720ef0 R09: 0000000002808040 R10: 0000000002808040 R11: 0000000000000246 R12: 0000200000005900 R13: 00007fe12f720eb0 R14: 0000000000005901 R15: 0000200000000200 Showing all locks held in the system: 1 lock held by pool_workqueue_/3: #0: ffffffff8e141a38 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline] #0: ffffffff8e141a38 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730 kernel/rcu/tree_exp.h:967 1 lock held by khungtaskd/31: #0: ffffffff8e13bf20 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e13bf20 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e13bf20 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770 2 locks held by kworker/u8:6/1089: #0: ffff88801ea9c948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #0: ffff88801ea9c948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3322 #1: ffffc90003d87bc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3215 [inline] #1: ffffc90003d87bc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3322 2 locks held by kworker/u8:11/3498: 2 locks held by getty/5593: #0: ffff88814dfd10a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000331b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 2 locks held by syz-executor/6243: #0: ffff888023c3c0e0 (&type->s_umount_key#85){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff888023c3c0e0 (&type->s_umount_key#85){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff888023c3c0e0 (&type->s_umount_key#85){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506 #1: ffff888024d807d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline] #1: ffff888024d807d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19f/0xa10 fs/fs-writeback.c:2831 2 locks held by syz-executor/6299: #0: ffff8880771b40e0 (&type->s_umount_key#85){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff8880771b40e0 (&type->s_umount_key#85){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff8880771b40e0 (&type->s_umount_key#85){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506 #1: ffff888024d867d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline] #1: ffff888024d867d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19f/0xa10 fs/fs-writeback.c:2831 1 lock held by syz-executor/6506: #0: ffffffff8e141a38 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline] #0: ffffffff8e141a38 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:967 2 locks held by segctord/7106: 2 locks held by syz.8.492/8203: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc3-next-20250627-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline] watchdog+0xfee/0x1030 kernel/hung_task.c:470 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 7106 Comm: segctord Not tainted 6.16.0-rc3-next-20250627-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:arch_irqs_disabled_flags arch/x86/include/asm/irqflags.h:146 [inline] RIP: 0010:check_preemption_disabled+0x5c/0x120 lib/smp_processor_id.c:19 Code: fd 30 07 48 3b 4c 24 08 0f 85 cc 00 00 00 48 83 c4 10 5b 41 5e 41 5f 5d e9 c1 bf 02 00 cc 48 c7 04 24 00 00 00 00 9c 8f 04 24 04 24 00 02 00 00 74 c8 65 4c 8b 3c 25 08 20 a0 92 41 f6 47 2f RSP: 0018:ffffc90003106fc0 EFLAGS: 00000046 RAX: 0000000000000001 RBX: 00000000ffffffff RCX: 0000000080000000 RDX: 0000000000000000 RSI: ffffffff8d9a62ad RDI: ffffffff8be31f80 RBP: 00000000ffffffff R08: ffff88804a3cad13 R09: 1ffff110094795a2 R10: dffffc0000000000 R11: ffffed10094795a3 R12: 0000000000000246 R13: ffff88802f910000 R14: ffffffff8e13bf80 R15: ffff88804a3cacb0 FS: 0000000000000000(0000) GS:ffff888125d1e000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f99ed77e2d8 CR3: 0000000075814000 CR4: 00000000003526f0 Call Trace: lockdep_recursion_inc kernel/locking/lockdep.c:468 [inline] lock_is_held_type+0x79/0x190 kernel/locking/lockdep.c:5942 lock_is_held include/linux/lockdep.h:249 [inline] __might_resched+0xa6/0x610 kernel/sched/core.c:8649 wait_on_buffer include/linux/buffer_head.h:418 [inline] __nilfs_get_folio_block fs/nilfs2/page.c:42 [inline] nilfs_grab_buffer+0x329/0x490 fs/nilfs2/page.c:60 nilfs_mdt_submit_block+0xaf/0x830 fs/nilfs2/mdt.c:123 nilfs_mdt_read_block+0x46/0x320 fs/nilfs2/mdt.c:178 nilfs_mdt_get_block+0x14b/0xb30 fs/nilfs2/mdt.c:254 nilfs_sufile_get_segment_usage_block fs/nilfs2/sufile.c:108 [inline] nilfs_sufile_set_segment_usage+0x147/0x410 fs/nilfs2/sufile.c:578 nilfs_cancel_segusage fs/nilfs2/segment.c:1504 [inline] nilfs_segctor_abort_construction+0x72c/0xdd0 fs/nilfs2/segment.c:1873 nilfs_segctor_do_construct+0x60df/0x6a40 fs/nilfs2/segment.c:2186 nilfs_segctor_construct+0x17b/0x690 fs/nilfs2/segment.c:2462 nilfs_segctor_thread_construct fs/nilfs2/segment.c:2570 [inline] nilfs_segctor_thread+0x6f7/0xe00 fs/nilfs2/segment.c:2684 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245