INFO: task syz-executor:4786 blocked for more than 143 seconds. Not tainted 5.15.186-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:22016 pid: 4786 ppid: 1 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5030 [inline] __schedule+0x11b8/0x43b0 kernel/sched/core.c:6376 schedule+0x11b/0x1e0 kernel/sched/core.c:6459 wb_wait_for_completion+0x164/0x290 fs/fs-writeback.c:191 __writeback_inodes_sb_nr+0x1f3/0x240 fs/fs-writeback.c:2684 sync_filesystem+0x9f/0x220 fs/sync.c:54 generic_shutdown_super+0x6b/0x300 fs/super.c:448 kill_block_super+0x7c/0xe0 fs/super.c:1427 kill_f2fs_super+0x2ed/0x3a0 fs/f2fs/super.c:4559 deactivate_locked_super+0x93/0xf0 fs/super.c:335 cleanup_mnt+0x418/0x4d0 fs/namespace.c:1139 task_work_run+0x125/0x1a0 kernel/task_work.c:188 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop+0x10f/0x130 kernel/entry/common.c:181 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:214 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f8d11706497 RSP: 002b:00007ffc041f4518 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007f8d1178608c RCX: 00007f8d11706497 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffc041f45d0 RBP: 00007ffc041f45d0 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffc041f5660 R13: 00007f8d1178608c R14: 000000000001b71d R15: 00007ffc041f56a0 Showing all locks held in the system: 4 locks held by kworker/u4:0/9: 1 lock held by khungtaskd/27: #0: ffffffff8c11bfa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 5 locks held by kworker/u4:1/144: 4 locks held by kworker/u4:2/154: 2 locks held by kworker/u4:3/155: #0: ffff8880b913a318 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:475 #1: ffff8880b9127848 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x4d6/0x810 kernel/sched/psi.c:891 2 locks held by getty/3933: #0: ffff88802b365098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252 #1: ffffc900025d62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5ba/0x1a30 drivers/tty/n_tty.c:2158 2 locks held by kworker/0:17/4256: 5 locks held by kworker/u4:5/4620: 1 lock held by syz-executor/4786: #0: ffff88807c2e60e0 (&type->s_umount_key#54){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365 1 lock held by syz-executor/5061: #0: ffff88807d9900e0 (&type->s_umount_key#54){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365 1 lock held by syz-executor/5088: #0: ffff88801e6aa0e0 (&type->s_umount_key#54){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365 5 locks held by kworker/u4:6/5106: 1 lock held by syz-executor/5121: #0: ffff8880779780e0 (&type->s_umount_key#54){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365 6 locks held by kworker/u4:7/5127: 1 lock held by syz-executor/5157: #0: ffff88807175c0e0 (&type->s_umount_key#54){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365 1 lock held by syz-executor/5217: #0: ffff888054bf80e0 (&type->s_umount_key#54){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365 2 locks held by syz-executor/5276: #0: ffff88801fad3118 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0xf9/0x7d0 block/bdev.c:915 #1: ffff88801fcba468 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0xaa/0xb90 drivers/block/loop.c:1366 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 27 Comm: khungtaskd Not tainted 5.15.186-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106 nmi_cpu_backtrace+0x397/0x3d0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline] watchdog+0xe0f/0xe50 kernel/hung_task.c:369 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 1176 Comm: kworker/u4:4 Not tainted 5.15.186-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Workqueue: bat_events batadv_nc_worker RIP: 0010:__raw_callee_save___pv_queued_spin_unlock+0xc/0x12 Code: 56 57 41 50 41 51 41 52 41 53 e8 2f 08 00 00 41 5b 41 5a 41 59 41 58 5f 5e 5a 59 c3 90 90 52 b8 01 00 00 00 31 d2 f0 0f b0 17 <3c> 01 75 02 5a c3 56 0f b6 f0 e8 c5 ff ff ff 5e 5a c3 66 90 55 48 RSP: 0018:ffffc900047f7ae8 EFLAGS: 00000246 RAX: 0000000000000001 RBX: ffff88807e591400 RCX: 0000000000000001 RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff88807e591400 RBP: 1ffff1100fcb2281 R08: dffffc0000000000 R09: ffffed100fcb2281 R10: ffffed100fcb2281 R11: 1ffff1100fcb2280 R12: dffffc0000000000 R13: 1ffff1100fcb2282 R14: ffff88807e591410 R15: ffff88807e591408 FS: 0000000000000000(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000555f86729030 CR3: 000000007a20c000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: pv_queued_spin_unlock arch/x86/include/asm/paravirt.h:590 [inline] queued_spin_unlock arch/x86/include/asm/qspinlock.h:56 [inline] do_raw_spin_unlock+0x11d/0x230 kernel/locking/spinlock_debug.c:141 __raw_spin_unlock_bh include/linux/spinlock_api_smp.h:175 [inline] _raw_spin_unlock_bh+0x1f/0x30 kernel/locking/spinlock.c:210 spin_unlock_bh include/linux/spinlock.h:408 [inline] batadv_nc_purge_paths+0x316/0x3b0 net/batman-adv/network-coding.c:475 batadv_nc_worker+0x327/0x5c0 net/batman-adv/network-coding.c:726 process_one_work+0x863/0x1000 kernel/workqueue.c:2310 worker_thread+0xaa8/0x12a0 kernel/workqueue.c:2457 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287