INFO: task kworker/u4:7:3732 blocked for more than 143 seconds. Not tainted 5.15.109-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:7 state:D stack:22712 pid: 3732 ppid: 2 flags:0x00004000 Workqueue: writeback wb_workfn (flush-7:5) Call Trace: context_switch kernel/sched/core.c:5026 [inline] __schedule+0x12c4/0x4590 kernel/sched/core.c:6372 schedule+0x11b/0x1f0 kernel/sched/core.c:6455 rwsem_down_write_slowpath+0xebb/0x15c0 kernel/locking/rwsem.c:1157 __down_write_common kernel/locking/rwsem.c:1284 [inline] __down_write kernel/locking/rwsem.c:1293 [inline] down_write+0x164/0x170 kernel/locking/rwsem.c:1542 f2fs_balance_fs+0x4d4/0x6a0 fs/f2fs/segment.c:529 f2fs_write_inode+0x4c3/0x540 fs/f2fs/inode.c:727 write_inode fs/fs-writeback.c:1475 [inline] __writeback_single_inode+0x644/0xe30 fs/fs-writeback.c:1680 writeback_sb_inodes+0xbf0/0x1a50 fs/fs-writeback.c:1905 __writeback_inodes_wb+0x114/0x400 fs/fs-writeback.c:1976 wb_writeback+0x465/0xc50 fs/fs-writeback.c:2081 wb_check_old_data_flush fs/fs-writeback.c:2181 [inline] wb_do_writeback fs/fs-writeback.c:2234 [inline] wb_workfn+0xc55/0x1130 fs/fs-writeback.c:2263 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2306 worker_thread+0xaca/0x1280 kernel/workqueue.c:2453 kthread+0x3f6/0x4f0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8c91c4e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 4 locks held by kworker/u4:5/1246: #0: ffff8880147cc938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2279 #1: ffffc900053cfd20 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2281 #2: ffff8880785cc0e0 (&type->s_umount_key#52){++++}-{3:3}, at: trylock_super+0x1b/0xf0 fs/super.c:418 #3: ffff88808b205108 (&sbi->gc_lock){+.+.}-{3:3}, at: f2fs_balance_fs+0x4d4/0x6a0 fs/f2fs/segment.c:529 1 lock held by udevd/2962: #0: ffff8880b9b39698 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:475 2 locks held by getty/3258: #0: ffff88814afaf098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252 #1: ffffc90002bb32e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6af/0x1da0 drivers/tty/n_tty.c:2147 2 locks held by kworker/0:10/3721: #0: ffff888011c66538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2279 #1: ffffc900049f7d20 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2281 4 locks held by kworker/u4:7/3732: #0: ffff8880147cc938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2279 #1: ffffc90004ad7d20 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2281 #2: ffff8880886700e0 (&type->s_umount_key#52){++++}-{3:3}, at: trylock_super+0x1b/0xf0 fs/super.c:418 #3: ffff888022eed108 (&sbi->gc_lock){+.+.}-{3:3}, at: f2fs_balance_fs+0x4d4/0x6a0 fs/f2fs/segment.c:529 2 locks held by syz-executor.4/9977: 5 locks held by syz-executor.5/10010: 3 locks held by kworker/u4:17/11720: #0: ffff8880b9b39698 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:475 #1: ffff8880b9b27848 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x53d/0x810 kernel/sched/psi.c:891 #2: ffff888077348d40 (&wdev->mtx){+.+.}-{3:3}, at: sdata_lock net/mac80211/ieee80211_i.h:1033 [inline] #2: ffff888077348d40 (&wdev->mtx){+.+.}-{3:3}, at: ieee80211_ibss_work+0xa0/0x1480 net/mac80211/ibss.c:1685 2 locks held by syz-executor.4/13549: #0: ffffffff8d9dbc28 (rtnl_mutex){+.+.}-{3:3}, at: dev_ioctl+0x346/0xf60 net/core/dev_ioctl.c:540 #1: ffffffff8c920a28 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:322 [inline] #1: ffffffff8c920a28 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x350/0x740 kernel/rcu/tree_exp.h:840 1 lock held by syz-executor.2/13546: #0: ffffffff8c920a28 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline] #0: ffffffff8c920a28 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x280/0x740 kernel/rcu/tree_exp.h:840 1 lock held by syz-executor.0/13556: #0: ffffffff8d9dbc28 (rtnl_mutex){+.+.}-{3:3}, at: __netlink_dump_start+0x12e/0x6f0 net/netlink/af_netlink.c:2376 1 lock held by syz-executor.1/13557: #0: ffffffff8d9dbc28 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:698 [inline] #0: ffffffff8d9dbc28 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x3a/0x1b0 drivers/net/tun.c:3431 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 27 Comm: khungtaskd Not tainted 5.15.109-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/14/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106 nmi_cpu_backtrace+0x46a/0x4a0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x181/0x2a0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:210 [inline] watchdog+0xe72/0xeb0 kernel/hung_task.c:295 kthread+0x3f6/0x4f0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 11720 Comm: kworker/u4:17 Not tainted 5.15.109-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/14/2023 Workqueue: bat_events batadv_nc_worker RIP: 0010:check_wait_context kernel/locking/lockdep.c:4690 [inline] RIP: 0010:__lock_acquire+0x5ef/0x1ff0 kernel/locking/lockdep.c:4961 Code: 48 8d 84 e8 20 0a 00 00 48 89 44 24 08 45 84 f6 0f 84 0c 04 00 00 0f b6 1b 48 8b 44 24 38 0f b6 04 10 84 c0 0f 85 6b 12 00 00 <41> f6 47 01 80 0f 85 ed 03 00 00 84 db 41 0f b6 c6 0f b6 f3 0f 44 RSP: 0018:ffffc90004c6f900 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff88805b49a720 RDX: dffffc0000000000 RSI: 0000000000000008 RDI: ffffffff8fbc71e0 RBP: 000000000000000a R08: dffffc0000000000 R09: fffffbfff1f78e3d R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000002 R13: ffff88805b49a718 R14: 0000000000000002 R15: ffff88805b49a790 FS: 0000000000000000(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000555557420708 CR3: 0000000083581000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5622 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline] _raw_spin_lock_bh+0x31/0x40 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:368 [inline] batadv_nc_purge_paths+0xe8/0x3b0 net/batman-adv/network-coding.c:446 batadv_nc_worker+0x30b/0x5b0 net/batman-adv/network-coding.c:726 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2306 worker_thread+0xaca/0x1280 kernel/workqueue.c:2453 kthread+0x3f6/0x4f0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298