INFO: task kworker/u8:6:1160 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:kworker/u8:6 state:D stack:22200 pid:1160 tgid:1160 ppid:2 task_flags:0x4208060 flags:0x00004000 Workqueue: writeback wb_workfn (flush-7:0) 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 io_schedule+0x81/0xe0 kernel/sched/core.c:7742 f2fs_balance_fs+0x4b4/0x780 fs/f2fs/segment.c:444 f2fs_write_inode+0x49d/0x870 fs/f2fs/inode.c:812 write_inode fs/fs-writeback.c:1525 [inline] __writeback_single_inode+0x6ee/0xff0 fs/fs-writeback.c:1745 writeback_sb_inodes+0x6b5/0x1000 fs/fs-writeback.c:1976 wb_writeback+0x43b/0xaf0 fs/fs-writeback.c:2156 wb_do_writeback fs/fs-writeback.c:2303 [inline] wb_workfn+0x409/0xef0 fs/fs-writeback.c:2343 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xadb/0x17a0 kernel/workqueue.c:3319 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400 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 INFO: task syz.0.96:6842 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.0.96 state:D stack:23000 pid:6842 tgid:6838 ppid:5821 task_flags:0x400140 flags:0x00004004 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 wb_wait_for_completion+0x15f/0x260 fs/fs-writeback.c:216 __writeback_inodes_sb_nr+0x1f6/0x250 fs/fs-writeback.c:2747 sync_filesystem+0xa3/0x230 fs/sync.c:54 freeze_super+0x4f9/0xeb0 fs/super.c:2052 fs_bdev_freeze+0x19f/0x310 fs/super.c:1484 bdev_freeze+0xd5/0x220 block/bdev.c:298 f2fs_do_shutdown+0x23d/0x5c0 fs/f2fs/file.c:2367 f2fs_ioc_shutdown fs/f2fs/file.c:2459 [inline] __f2fs_ioctl+0x3de9/0xae80 fs/f2fs/file.c:4558 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: 0033:0x7efd7e18e969 RSP: 002b:00007efd7ef1a038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007efd7e3b5fa0 RCX: 00007efd7e18e969 RDX: 0000200000000080 RSI: 000000008004587d RDI: 0000000000000009 RBP: 00007efd7e210ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007efd7e3b5fa0 R15: 00007fff6748a888 Showing all locks held in the system: 1 lock held by pool_workqueue_/3: 1 lock held by khungtaskd/31: #0: ffffffff8df3b860 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6764 2 locks held by kworker/u8:5/1107: 2 locks held by kworker/u8:6/1160: #0: ffff8881412da148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff8881412da148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b1/0x17a0 kernel/workqueue.c:3319 #1: ffffc90003c2fc60 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc90003c2fc60 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319 2 locks held by getty/5572: #0: ffff888030cb20a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90002ffe2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 1 lock held by syz-executor/6487: #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 4 locks held by syz.0.96/6842: #0: ffff888148c8bb30 (&bdev->bd_fsfreeze_mutex){+.+.}-{4:4}, at: bdev_freeze+0x2a/0x220 block/bdev.c:289 #1: ffff88805ac14420 (sb_writers#15){++++}-{0:0}, at: sb_wait_write fs/super.c:1855 [inline] #1: ffff88805ac14420 (sb_writers#15){++++}-{0:0}, at: freeze_super+0x4c2/0xeb0 fs/super.c:2044 #2: ffff88805ac140e0 (&type->s_umount_key#61){++++}-{4:4}, at: __super_lock fs/super.c:56 [inline] #2: ffff88805ac140e0 (&type->s_umount_key#61){++++}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline] #2: ffff88805ac140e0 (&type->s_umount_key#61){++++}-{4:4}, at: freeze_super+0x4ca/0xeb0 fs/super.c:2045 #3: ffff88805ac14518 (sb_pagefaults#2){+.+.}-{0:0}, at: sb_wait_write fs/super.c:1855 [inline] #3: ffff88805ac14518 (sb_pagefaults#2){+.+.}-{0:0}, at: freeze_super+0x4f1/0xeb0 fs/super.c:2049 3 locks held by kworker/u8:10/7840: 1 lock held by syz.2.262/8480: #0: ffff88805ac140e0 (&type->s_umount_key#61){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff88805ac140e0 (&type->s_umount_key#61){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:120 1 lock held by syz.0.265/8514: #0: ffff88805ac140e0 (&type->s_umount_key#61){++++}-{4:4}, at: __super_lock fs/super.c:56 [inline] #0: ffff88805ac140e0 (&type->s_umount_key#61){++++}-{4:4}, at: super_lock+0x25c/0x3b0 fs/super.c:120 2 locks held by syz.7.317/9242: #0: ffff88814d87c0e0 (&type->s_umount_key#65){++++}-{4:4}, at: do_remount fs/namespace.c:3365 [inline] #0: ffff88814d87c0e0 (&type->s_umount_key#65){++++}-{4:4}, at: path_mount+0xcd2/0xfe0 fs/namespace.c:4203 #1: ffff888045080278 (&c->state_lock){++++}-{4:4}, at: bch2_fs_reconfigure+0x17e/0x400 fs/bcachefs/fs.c:2670 4 locks held by dhcpcd-run-hook/9279: ============================================= NMI backtrace for cpu 1 CPU: 1 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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 7840 Comm: kworker/u8:10 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 Workqueue: bat_events batadv_nc_worker RIP: 0010:check_preemption_disabled+0x17/0x120 lib/smp_processor_id.c:14 Code: 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 55 41 57 41 56 53 48 83 ec 10 65 48 8b 05 4e 1e 23 07 48 89 44 24 08 <65> 8b 05 56 1e 23 07 65 8b 0d 4b 1e 23 07 f7 c1 ff ff ff 7f 74 23 RSP: 0018:ffffc90004e9f9b0 EFLAGS: 00000082 RAX: 4c7a69d935304d00 RBX: 0000000000000206 RCX: 4c7a69d935304d00 RDX: 0000000000000002 RSI: ffffffff8d9208d6 RDI: ffffffff8bc0fa60 RBP: ffff888061a6c740 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: ffffffff8b1d352a R12: 0000000000000002 R13: 0000000000000002 R14: ffffffff8df3b860 R15: ffff888061a6bc00 FS: 0000000000000000(0000) GS:ffff888126100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000558d37234950 CR3: 000000000dd36000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lockdep_recursion_finish kernel/locking/lockdep.c:472 [inline] lock_release+0x27a/0x3e0 kernel/locking/lockdep.c:5889 rcu_lock_release include/linux/rcupdate.h:341 [inline] rcu_read_unlock include/linux/rcupdate.h:871 [inline] batadv_nc_process_nc_paths+0x2f9/0x3a0 net/batman-adv/network-coding.c:699 batadv_nc_worker+0x429/0x610 net/batman-adv/network-coding.c:728 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xadb/0x17a0 kernel/workqueue.c:3319 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400 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