INFO: task syz.2.38:6101 blocked for more than 143 seconds. Not tainted 6.15.0-rc4-syzkaller-00042-gb6ea1680d0ac #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.38 state:D stack:24976 pid:6101 tgid:6099 ppid:5830 task_flags:0x400140 flags:0x00024006 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x168f/0x4c70 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0x165/0x360 kernel/sched/core.c:6860 schedule_timeout+0x9a/0x270 kernel/time/sleep_timeout.c:75 do_wait_for_common kernel/sched/completion.c:95 [inline] __wait_for_common kernel/sched/completion.c:116 [inline] wait_for_common kernel/sched/completion.c:127 [inline] wait_for_completion+0x2bf/0x5d0 kernel/sched/completion.c:148 f2fs_issue_checkpoint+0x2f2/0x490 fs/f2fs/checkpoint.c:-1 f2fs_do_sync_file+0x86a/0x1860 fs/f2fs/file.c:330 generic_write_sync include/linux/fs.h:2976 [inline] f2fs_file_write_iter+0x78e/0x2340 fs/f2fs/file.c:5189 new_sync_write fs/read_write.c:591 [inline] vfs_write+0x548/0xa90 fs/read_write.c:684 ksys_write+0x145/0x250 fs/read_write.c:736 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f7cc9b8e969 RSP: 002b:00007f7cca942038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f7cc9db5fa0 RCX: 00007f7cc9b8e969 RDX: 00000000ffffff71 RSI: 0000200000000400 RDI: 0000000000000004 RBP: 00007f7cc9c10ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f7cc9db5fa0 R15: 00007ffe5ee66338 INFO: task syz.2.38:6128 blocked for more than 144 seconds. Not tainted 6.15.0-rc4-syzkaller-00042-gb6ea1680d0ac #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.38 state:D stack:28952 pid:6128 tgid:6099 ppid:5830 task_flags:0x400040 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x168f/0x4c70 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0x165/0x360 kernel/sched/core.c:6860 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6917 __mutex_lock_common kernel/locking/mutex.c:678 [inline] __mutex_lock+0x724/0xe80 kernel/locking/mutex.c:746 fdget_pos+0x247/0x320 fs/file.c:1213 class_fd_pos_constructor include/linux/file.h:85 [inline] ksys_write+0x79/0x250 fs/read_write.c:727 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f7cc9b8e969 RSP: 002b:00007f7cca921038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f7cc9db6080 RCX: 00007f7cc9b8e969 RDX: 0000000000000020 RSI: 0000200000000100 RDI: 0000000000000004 RBP: 00007f7cc9c10ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007f7cc9db6080 R15: 00007ffe5ee66338 INFO: task syz.2.38:6129 blocked for more than 145 seconds. Not tainted 6.15.0-rc4-syzkaller-00042-gb6ea1680d0ac #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.38 state:D stack:24824 pid:6129 tgid:6099 ppid:5830 task_flags:0x400040 flags:0x00000006 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x168f/0x4c70 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0x165/0x360 kernel/sched/core.c:6860 schedule_timeout+0x9a/0x270 kernel/time/sleep_timeout.c:75 do_wait_for_common kernel/sched/completion.c:95 [inline] __wait_for_common kernel/sched/completion.c:116 [inline] wait_for_common kernel/sched/completion.c:127 [inline] wait_for_completion+0x2bf/0x5d0 kernel/sched/completion.c:148 f2fs_issue_checkpoint+0x2f2/0x490 fs/f2fs/checkpoint.c:-1 f2fs_do_sync_file+0x86a/0x1860 fs/f2fs/file.c:330 f2fs_ioc_commit_atomic_write fs/f2fs/file.c:2320 [inline] __f2fs_ioctl+0x483a/0xae80 fs/f2fs/file.c:4551 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:906 [inline] __se_sys_ioctl+0xf9/0x170 fs/ioctl.c:892 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f7cc9b8e969 RSP: 002b:00007f7cc79f6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f7cc9db6160 RCX: 00007f7cc9b8e969 RDX: 0000000000000000 RSI: 000000000000f502 RDI: 0000000000000004 RBP: 00007f7cc9c10ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f7cc9db6160 R15: 00007ffe5ee66338 Showing all locks held in the system: 1 lock held by pool_workqueue_/3: #0: ffffffff8df41338 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:336 [inline] #0: ffffffff8df41338 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b7/0x730 kernel/rcu/tree_exp.h:998 2 locks held by kworker/u8:1/13: #0: ffff888147ae9948 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff888147ae9948 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_scheduled_works+0x9b1/0x17a0 kernel/workqueue.c:3319 #1: ffffc90000127c60 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc90000127c60 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319 1 lock held by khungtaskd/31: #0: ffffffff8df3b860 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8df3b860 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8df3b860 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6764 2 locks held by kworker/u8:3/54: #0: ffff8880b89399d8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:605 #1: ffffc90000bf7c60 ((work_completion)(&(&bat_priv->nc.work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc90000bf7c60 ((work_completion)(&(&bat_priv->nc.work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319 3 locks held by kworker/u8:7/3029: #0: ffff88814428a148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88814428a148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b1/0x17a0 kernel/workqueue.c:3319 #1: ffffc9000c1d7c60 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc9000c1d7c60 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319 #2: ffff88802f6f20e0 (&type->s_umount_key#53){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:562 2 locks held by getty/5576: #0: ffff88803146c0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90002fee2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 3 locks held by kworker/1:5/5885: #0: ffff88801a080d48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801a080d48 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b1/0x17a0 kernel/workqueue.c:3319 #1: ffffc9000435fc60 (key_gc_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc9000435fc60 (key_gc_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319 #2: ffffffff8df41338 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:336 [inline] #2: ffffffff8df41338 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b7/0x730 kernel/rcu/tree_exp.h:998 2 locks held by syz.2.38/6101: #0: ffff888030273cf8 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x247/0x320 fs/file.c:1213 #1: ffff88802f6f2420 (sb_writers#12){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3041 [inline] #1: ffff88802f6f2420 (sb_writers#12){.+.+}-{0:0}, at: vfs_write+0x211/0xa90 fs/read_write.c:680 1 lock held by syz.2.38/6128: #0: ffff888030273cf8 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x247/0x320 fs/file.c:1213 2 locks held by syz.2.38/6129: #0: ffff88802f6f2420 (sb_writers#12){.+.+}-{0:0}, at: mnt_want_write_file+0x60/0x200 fs/namespace.c:600 #1: ffff88805fedd1b8 (&sb->s_type->i_mutex_key#26){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:867 [inline] #1: ffff88805fedd1b8 (&sb->s_type->i_mutex_key#26){+.+.}-{4:4}, at: f2fs_ioc_commit_atomic_write fs/f2fs/file.c:2315 [inline] #1: ffff88805fedd1b8 (&sb->s_type->i_mutex_key#26){+.+.}-{4:4}, at: __f2fs_ioctl+0x39c5/0xae80 fs/f2fs/file.c:4551 2 locks held by f2fs_ckpt-7:2/6124: 2 locks held by syz.3.210/8009: #0: ffff88802f6f20e0 (&type->s_umount_key#53){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff88802f6f20e0 (&type->s_umount_key#53){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:120 #1: ffff888143f787d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline] #1: ffff888143f787d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19f/0xa10 fs/fs-writeback.c:2831 2 locks held by dhcpcd-run-hook/8713: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-rc4-syzkaller-00042-gb6ea1680d0ac #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025 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:158 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:274 [inline] watchdog+0xfee/0x1030 kernel/hung_task.c:437 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153 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: 8658 Comm: syz.9.273 Not tainted 6.15.0-rc4-syzkaller-00042-gb6ea1680d0ac #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025 RIP: 0010:io_serial_in+0x77/0xc0 drivers/tty/serial/8250/8250_port.c:409 Code: e8 6e 4d 89 fc 44 89 f9 d3 e3 49 83 c6 40 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 af 1c e9 fc 41 03 1e 89 da ec <0f> b6 c0 5b 41 5c 41 5e 41 5f c3 cc cc cc cc cc 44 89 f9 80 e1 07 RSP: 0018:ffffc9000423f3b8 EFLAGS: 00000006 RAX: 1ffffffff3362f05 RBX: 00000000000003f9 RCX: 0000000000000000 RDX: 00000000000003f9 RSI: 000000000007875b RDI: 000000000007875c RBP: ffffc9000423f590 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: ffffffff85367020 R12: dffffc0000000000 R13: dffffc0000000000 R14: ffffffff99b17980 R15: 0000000000000000 FS: 00007f4ffafbe6c0(0000) GS:ffff888126200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f76b9ad2378 CR3: 000000005cb76000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: serial_port_in include/linux/serial_core.h:791 [inline] serial8250_console_write+0x581/0x1ba0 drivers/tty/serial/8250/8250_port.c:3420 console_emit_next_record kernel/printk/printk.c:3138 [inline] console_flush_all+0x725/0xc40 kernel/printk/printk.c:3226 __console_flush_and_unlock kernel/printk/printk.c:3285 [inline] console_unlock+0xc4/0x270 kernel/printk/printk.c:3325 vprintk_emit+0x5b7/0x7a0 kernel/printk/printk.c:2450 bch2_print_maybe_redirect fs/bcachefs/super.c:110 [inline] __bch2_print+0x176/0x220 fs/bcachefs/super.c:129 bch2_fs_free+0x37e/0x400 fs/bcachefs/super.c:670 deactivate_locked_super+0xb9/0x130 fs/super.c:473 bch2_fs_get_tree+0xe07/0x1340 fs/bcachefs/fs.c:2612 vfs_get_tree+0x8f/0x2b0 fs/super.c:1759 do_new_mount+0x24a/0xa40 fs/namespace.c:3884 do_mount fs/namespace.c:4224 [inline] __do_sys_mount fs/namespace.c:4435 [inline] __se_sys_mount+0x317/0x410 fs/namespace.c:4412 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f4ffa19010a Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 1a 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f4ffafbde68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f4ffafbdef0 RCX: 00007f4ffa19010a RDX: 0000200000000140 RSI: 0000200000000100 RDI: 00007f4ffafbdeb0 RBP: 0000200000000140 R08: 00007f4ffafbdef0 R09: 0000000000000010 R10: 0000000000000010 R11: 0000000000000246 R12: 0000200000000100 R13: 00007f4ffafbdeb0 R14: 0000000000005a76 R15: 0000200000000080