INFO: task syz-executor.4:16997 blocked for more than 143 seconds. Not tainted 6.10.0-rc3-syzkaller-00044-g2ccbdf43d5e7 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.4 state:D stack:24192 pid:16997 tgid:16997 ppid:1 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5408 [inline] __schedule+0xf15/0x5d00 kernel/sched/core.c:6745 __schedule_loop kernel/sched/core.c:6822 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6837 wb_wait_for_completion+0x1b2/0x270 fs/fs-writeback.c:216 __writeback_inodes_sb_nr+0x1d8/0x280 fs/fs-writeback.c:2706 sync_filesystem+0xba/0x290 fs/sync.c:54 generic_shutdown_super+0x7e/0x3d0 fs/super.c:621 bch2_kill_sb+0x3b/0x50 fs/bcachefs/fs.c:2037 deactivate_locked_super+0xbe/0x1a0 fs/super.c:473 deactivate_super+0xde/0x100 fs/super.c:506 cleanup_mnt+0x222/0x450 fs/namespace.c:1267 task_work_run+0x14e/0x250 kernel/task_work.c:180 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop kernel/entry/common.c:114 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x278/0x2a0 kernel/entry/common.c:218 do_syscall_64+0xda/0x250 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f4a2067e1d7 RSP: 002b:00007ffd4f62a468 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f4a2067e1d7 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffd4f62a520 RBP: 00007ffd4f62a520 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffd4f62b5d0 R13: 00007f4a206d9636 R14: 00007f4a206cad68 R15: 0000000000000019 Showing all locks held in the system: no locks held by ksoftirqd/1/24. 1 lock held by khungtaskd/30: #0: ffffffff8dbb1920 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #0: ffffffff8dbb1920 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #0: ffffffff8dbb1920 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x75/0x340 kernel/locking/lockdep.c:6614 2 locks held by kworker/u8:2/35: #0: ffff888019ac9148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x12bf/0x1b60 kernel/workqueue.c:3206 #1: ffffc90000ab7d80 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x957/0x1b60 kernel/workqueue.c:3207 2 locks held by kworker/u8:4/61: #0: ffff888019bf2948 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work+0x12bf/0x1b60 kernel/workqueue.c:3206 #1: ffffc900015c7d80 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x957/0x1b60 kernel/workqueue.c:3207 2 locks held by getty/4845: #0: ffff88802a9550a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc90002f062f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xfc8/0x1490 drivers/tty/n_tty.c:2201 2 locks held by syz-fuzzer/5093: 1 lock held by syz-executor.4/16997: #0: ffff8880226a20e0 (&type->s_umount_key#118){+.+.}-{3:3}, at: __super_lock fs/super.c:56 [inline] #0: ffff8880226a20e0 (&type->s_umount_key#118){+.+.}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff8880226a20e0 (&type->s_umount_key#118){+.+.}-{3:3}, at: deactivate_super+0xd6/0x100 fs/super.c:505 1 lock held by syz-executor.2/17069: #0: ffffffff8dbbd0b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock+0x1a4/0x3b0 kernel/rcu/tree_exp.h:323 1 lock held by syz-executor.1/17810: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 30 Comm: khungtaskd Not tainted 6.10.0-rc3-syzkaller-00044-g2ccbdf43d5e7 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:114 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline] watchdog+0xf86/0x1240 kernel/hung_task.c:379 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 17069 Comm: syz-executor.2 Not tainted 6.10.0-rc3-syzkaller-00044-g2ccbdf43d5e7 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024 RIP: 0010:visit_lock_entry kernel/locking/lockdep.c:1520 [inline] RIP: 0010:__bfs+0x3e7/0x670 kernel/locking/lockdep.c:1800 Code: 89 05 8d bf 27 12 eb 26 48 8b 1b 4c 39 cb 0f 84 4e fe ff ff 48 8d 7b 30 48 89 f8 48 c1 e8 03 42 80 3c 30 00 0f 85 fb 00 00 00 <4c> 89 7b 30 48 89 d8 48 c1 e8 03 42 80 3c 30 00 74 cc 48 89 df 4c RSP: 0018:ffffc90003286a70 EFLAGS: 00000046 RAX: 1ffffffff288306c RBX: ffffffff94418330 RCX: ffffffff816b2408 RDX: 1ffffffff2881b68 RSI: 1ffffffff2725c0e RDI: ffffffff94418360 RBP: ffffffff9440db40 R08: 0000000000000000 R09: ffffffff942743f8 R10: 0000000000000002 R11: 0000000000000002 R12: 0000000000000000 R13: ffffffff9440db60 R14: dffffc0000000000 R15: ffffffff9440db30 FS: 0000000000000000(0000) GS:ffff8880b9300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000000d97a000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __bfs_forwards kernel/locking/lockdep.c:1832 [inline] check_path.constprop.0+0x24/0x50 kernel/locking/lockdep.c:2143 check_noncircular+0x160/0x400 kernel/locking/lockdep.c:2172 check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain kernel/locking/lockdep.c:3869 [inline] __lock_acquire+0x2478/0x3b30 kernel/locking/lockdep.c:5137 lock_acquire kernel/locking/lockdep.c:5754 [inline] lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5719 local_lock_acquire include/linux/local_lock_internal.h:29 [inline] __radix_tree_preload+0x94/0x850 lib/radix-tree.c:334 alloc_extent_buffer+0x1e61/0x2560 fs/btrfs/extent_io.c:3978 btrfs_init_new_buffer fs/btrfs/extent-tree.c:5036 [inline] btrfs_alloc_tree_block+0x301/0x1190 fs/btrfs/extent-tree.c:5150 btrfs_force_cow_block+0x3e5/0x19e0 fs/btrfs/ctree.c:568 btrfs_cow_block+0x2b6/0xb70 fs/btrfs/ctree.c:746 btrfs_search_slot+0x11bd/0x3010 fs/btrfs/ctree.c:2101 update_dev_stat_item fs/btrfs/volumes.c:7781 [inline] btrfs_run_dev_stats+0x29c/0xe80 fs/btrfs/volumes.c:7858 commit_cowonly_roots+0x208/0xa60 fs/btrfs/transaction.c:1345 btrfs_commit_transaction+0x1384/0x3b30 fs/btrfs/transaction.c:2429 btrfs_commit_super+0xc9/0x110 fs/btrfs/disk-io.c:4173 close_ctree+0xcb0/0xf90 fs/btrfs/disk-io.c:4324 generic_shutdown_super+0x159/0x3d0 fs/super.c:642 kill_anon_super+0x3a/0x60 fs/super.c:1226 btrfs_kill_super+0x3b/0x50 fs/btrfs/super.c:2096 deactivate_locked_super+0xbe/0x1a0 fs/super.c:473 deactivate_super+0xde/0x100 fs/super.c:506 cleanup_mnt+0x222/0x450 fs/namespace.c:1267 task_work_run+0x14e/0x250 kernel/task_work.c:180 exit_task_work include/linux/task_work.h:38 [inline] do_exit+0xa9b/0x2ba0 kernel/exit.c:874 do_group_exit+0xd3/0x2a0 kernel/exit.c:1023 get_signal+0x2616/0x2710 kernel/signal.c:2909 arch_do_signal_or_restart+0x90/0x7e0 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x14a/0x2a0 kernel/entry/common.c:218 do_syscall_64+0xda/0x250 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff76a4a82b5 Code: Unable to access opcode bytes at 0x7ff76a4a828b. RSP: 002b:00007ffd8a66cf00 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6 RAX: 0000000000000000 RBX: 00000000000001a5 RCX: 00007ff76a4a82b5 RDX: 00007ffd8a66cf40 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007ffd8a66cfbc R08: 0000000000000000 R09: 00007ff76b1d9080 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000032 R13: 0000000000161af1 R14: 00000000001618ca R15: 000000000000000f