INFO: task kworker/u4:3:49 blocked for more than 143 seconds. Not tainted 6.8.0-rc5-syzkaller-00329-gab0a97cffa0b #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:3 state:D stack:20056 pid:49 tgid:49 ppid:2 flags:0x00004000 Workqueue: writeback wb_workfn (flush-7:2) Call Trace: context_switch kernel/sched/core.c:5400 [inline] __schedule+0x177f/0x49a0 kernel/sched/core.c:6727 __schedule_loop kernel/sched/core.c:6802 [inline] schedule+0x149/0x260 kernel/sched/core.c:6817 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6874 rwsem_down_write_slowpath+0xeea/0x13b0 kernel/locking/rwsem.c:1178 __down_write_common+0x1ae/0x200 kernel/locking/rwsem.c:1306 f2fs_down_write fs/f2fs/f2fs.h:2138 [inline] f2fs_balance_fs+0x500/0x730 fs/f2fs/segment.c:437 f2fs_write_inode+0x3f0/0x470 fs/f2fs/inode.c:794 write_inode fs/fs-writeback.c:1473 [inline] __writeback_single_inode+0x69f/0xfd0 fs/fs-writeback.c:1690 writeback_sb_inodes+0x8e3/0x1220 fs/fs-writeback.c:1916 __writeback_inodes_wb+0x11b/0x260 fs/fs-writeback.c:1987 wb_writeback+0x461/0xc80 fs/fs-writeback.c:2094 wb_check_old_data_flush fs/fs-writeback.c:2198 [inline] wb_do_writeback fs/fs-writeback.c:2251 [inline] wb_workfn+0xb7c/0xfb0 fs/fs-writeback.c:2279 process_one_work kernel/workqueue.c:2633 [inline] process_scheduled_works+0x913/0x1420 kernel/workqueue.c:2706 worker_thread+0xa5f/0x1000 kernel/workqueue.c:2787 kthread+0x2ef/0x390 kernel/kthread.c:388 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1b/0x30 arch/x86/entry/entry_64.S:242 Showing all locks held in the system: 1 lock held by khungtaskd/29: #0: ffffffff8e130c60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline] #0: ffffffff8e130c60 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:750 [inline] #0: ffffffff8e130c60 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6614 4 locks held by kworker/u4:3/49: #0: ffff8880192e5538 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2608 [inline] #0: ffff8880192e5538 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x825/0x1420 kernel/workqueue.c:2706 #1: ffffc90000b9fd20 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2608 [inline] #1: ffffc90000b9fd20 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x825/0x1420 kernel/workqueue.c:2706 #2: ffff8880163100e0 (&type->s_umount_key#58){++++}-{3:3}, at: super_trylock_shared+0x22/0xf0 fs/super.c:566 #3: ffff88802f3f92a8 (&sbi->gc_lock){+.+.}-{3:3}, at: f2fs_down_write fs/f2fs/f2fs.h:2138 [inline] #3: ffff88802f3f92a8 (&sbi->gc_lock){+.+.}-{3:3}, at: f2fs_balance_fs+0x500/0x730 fs/f2fs/segment.c:437 2 locks held by getty/4806: #0: ffff88802fcd20a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90002f062f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6b4/0x1e10 drivers/tty/n_tty.c:2201 1 lock held by syz-executor.1/5081: 1 lock held by syz-executor.0/5084: #0: ffffffff8e1365f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:292 [inline] #0: ffffffff8e1365f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3a3/0x890 kernel/rcu/tree_exp.h:995 5 locks held by syz-executor.2/7161: 2 locks held by udevd/7410: #0: ffff8880b943c918 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:559 #1: ffff8880b9428988 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x441/0x770 kernel/sched/psi.c:988 1 lock held by syz-executor.3/9811: #0: ffff8880332e8ef0 (&iint_mutex_key[depth]){+.+.}-{3:3}, at: ima_check_last_writer security/integrity/ima/ima_main.c:165 [inline] #0: ffff8880332e8ef0 (&iint_mutex_key[depth]){+.+.}-{3:3}, at: ima_file_free+0x17c/0x4b0 security/integrity/ima/ima_main.c:204 2 locks held by syz-executor.3/9822: 1 lock held by syz-executor.2/9842: 2 locks held by syz-executor.1/9843: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 29 Comm: khungtaskd Not tainted 6.8.0-rc5-syzkaller-00329-gab0a97cffa0b #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e7/0x2e0 lib/dump_stack.c:106 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline] watchdog+0xfaf/0xff0 kernel/hung_task.c:379 kthread+0x2ef/0x390 kernel/kthread.c:388 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1b/0x30 arch/x86/entry/entry_64.S:242 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 158 Comm: kworker/u4:5 Not tainted 6.8.0-rc5-syzkaller-00329-gab0a97cffa0b #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024 Workqueue: writeback wb_workfn (flush-7:4) RIP: 0010:check_kcov_mode kernel/kcov.c:184 [inline] RIP: 0010:write_comp_data kernel/kcov.c:236 [inline] RIP: 0010:__sanitizer_cov_trace_cmp8+0x34/0x90 kernel/kcov.c:284 Code: 8b 0d 00 50 70 7e 65 8b 05 01 50 70 7e a9 00 01 ff 00 74 10 a9 00 01 00 00 74 57 83 b9 fc 15 00 00 00 74 4e 8b 81 d8 15 00 00 <83> f8 03 75 43 48 8b 91 e0 15 00 00 44 8b 89 dc 15 00 00 49 c1 e1 RSP: 0018:ffffc90002fce940 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffffffff81000000 RCX: ffff88801cf09dc0 RDX: ffffc90002fcea55 RSI: ffffffff81000000 RDI: ffffffff81e6c9ae RBP: ffffffff81e6c9ae R08: ffffffff81404f2e R09: ffffc90002fceb10 R10: 0000000000000003 R11: ffffffff818043c0 R12: ffffc90002fcea20 R13: ffffc90002fcea70 R14: dffffc0000000000 R15: ffffffff81e6c9af FS: 0000000000000000(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f37339cb000 CR3: 000000002a39a000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: orc_find arch/x86/kernel/unwind_orc.c:206 [inline] unwind_next_frame+0x1de/0x29e0 arch/x86/kernel/unwind_orc.c:494 arch_stack_walk+0x150/0x1b0 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x117/0x1d0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 unpoison_slab_object mm/kasan/common.c:314 [inline] __kasan_slab_alloc+0x66/0x80 mm/kasan/common.c:340 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook mm/slub.c:3813 [inline] slab_alloc_node mm/slub.c:3860 [inline] kmem_cache_alloc+0x16f/0x340 mm/slub.c:3867 f2fs_kmem_cache_alloc_nofail fs/f2fs/f2fs.h:2800 [inline] f2fs_kmem_cache_alloc fs/f2fs/f2fs.h:2810 [inline] add_free_nid+0xdd/0x830 fs/f2fs/node.c:2297 scan_free_nid_bits fs/f2fs/node.c:2448 [inline] __f2fs_build_free_nids fs/f2fs/node.c:2482 [inline] f2fs_build_free_nids+0x514/0x11e0 fs/f2fs/node.c:2547 f2fs_balance_fs_bg+0x167/0x950 fs/f2fs/segment.c:484 f2fs_write_node_pages+0x146/0x6a0 fs/f2fs/node.c:2118 do_writepages+0x3aa/0x680 mm/page-writeback.c:2553 __writeback_single_inode+0x155/0xfd0 fs/fs-writeback.c:1625 writeback_sb_inodes+0x8e3/0x1220 fs/fs-writeback.c:1916 wb_writeback+0x44d/0xc80 fs/fs-writeback.c:2092 wb_do_writeback fs/fs-writeback.c:2239 [inline] wb_workfn+0x400/0xfb0 fs/fs-writeback.c:2279 process_one_work kernel/workqueue.c:2633 [inline] process_scheduled_works+0x913/0x1420 kernel/workqueue.c:2706 worker_thread+0xa5f/0x1000 kernel/workqueue.c:2787 kthread+0x2ef/0x390 kernel/kthread.c:388 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1b/0x30 arch/x86/entry/entry_64.S:242