INFO: task syz-executor:8885 blocked for more than 143 seconds. Not tainted 6.15.0-rc4-syzkaller-00147-gebd297a2affa #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:16680 pid:8885 tgid:8885 ppid:1 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 generic_shutdown_super+0x6f/0x2c0 fs/super.c:621 kill_block_super+0x44/0x90 fs/super.c:1710 kill_f2fs_super+0x390/0x6c0 fs/f2fs/super.c:5032 deactivate_locked_super+0xb9/0x130 fs/super.c:473 cleanup_mnt+0x425/0x4c0 fs/namespace.c:1435 task_work_run+0x1d1/0x260 kernel/task_work.c:227 resume_user_mode_work+0x5e/0x80 include/linux/resume_user_mode.h:50 exit_to_user_mode_loop kernel/entry/common.c:114 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x9a/0x120 kernel/entry/common.c:218 do_syscall_64+0x103/0x210 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd47958fc97 RSP: 002b:00007ffe4829e248 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007fd47961089d RCX: 00007fd47958fc97 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffe4829e300 RBP: 00007ffe4829e300 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffe4829f390 R13: 00007fd47961089d R14: 000000000008dd7f R15: 00007ffe4829f3d0 Showing all locks held in the system: 3 locks held by kworker/u8:0/12: #0: ffff88814d944948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88814d944948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9b1/0x17a0 kernel/workqueue.c:3319 #1: ffffc90000117c60 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc90000117c60 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319 #2: ffffffff8f2e1fc8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff8f2e1fc8 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x112/0x14b0 net/ipv6/addrconf.c:4195 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 3 locks held by kworker/u8:4/68: 3 locks held by kworker/u8:5/996: #0: ffff88801a089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801a089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b1/0x17a0 kernel/workqueue.c:3319 #1: ffffc90003a7fc60 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc90003a7fc60 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319 #2: ffffffff8f2e1fc8 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303 5 locks held by kworker/u8:7/3505: #0: ffff88801aef3948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801aef3948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b1/0x17a0 kernel/workqueue.c:3319 #1: ffffc9000c817c60 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc9000c817c60 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319 #2: ffffffff8f2d5490 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0x145/0xbd0 net/core/net_namespace.c:608 #3: ffffffff8f2e1fc8 (rtnl_mutex){+.+.}-{4:4}, at: default_device_exit_batch+0xdc/0x890 net/core/dev.c:12524 #4: ffffffff8df41338 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:336 [inline] #4: ffffffff8df41338 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b7/0x730 kernel/rcu/tree_exp.h:998 2 locks held by dhcpcd/5483: #0: ffff8880319436d0 (nlk_cb_mutex-ROUTE){+.+.}-{4:4}, at: netlink_dump+0xcd/0xe70 net/netlink/af_netlink.c:2255 #1: ffffffff8f2e1fc8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8f2e1fc8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dumpit+0x92/0x200 net/core/rtnetlink.c:6823 2 locks held by getty/5565: #0: ffff8880345920a0 (&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/8885: #0: ffff88807dbd60e0 (&type->s_umount_key#68){++++}-{4:4}, at: __super_lock fs/super.c:56 [inline] #0: ffff88807dbd60e0 (&type->s_umount_key#68){++++}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff88807dbd60e0 (&type->s_umount_key#68){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:505 3 locks held by kworker/1:8/9679: #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: ffffc90002f27c60 (free_ipc_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc90002f27c60 (free_ipc_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 3 locks held by kworker/u9:0/14151: #0: ffff888033e2e948 ((wq_completion)hci6){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff888033e2e948 ((wq_completion)hci6){+.+.}-{0:0}, at: process_scheduled_works+0x9b1/0x17a0 kernel/workqueue.c:3319 #1: ffffc9000439fc60 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc9000439fc60 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319 #2: ffff88804d190d80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x1d4/0x3a0 net/bluetooth/hci_sync.c:331 1 lock held by syz.9.973/15197: #0: ffff88807dbd60e0 (&type->s_umount_key#68){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff88807dbd60e0 (&type->s_umount_key#68){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:120 1 lock held by syz.1.985/15339: #0: ffff88807dbd60e0 (&type->s_umount_key#68){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff88807dbd60e0 (&type->s_umount_key#68){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:120 1 lock held by syz-executor/16341: #0: ffffffff8f2e1fc8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8f2e1fc8 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x3b0/0x18b0 net/ipv4/devinet.c:979 1 lock held by syz-executor/16471: #0: ffffffff8f2e1fc8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8f2e1fc8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #0: ffffffff8f2e1fc8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8db/0x1c70 net/core/rtnetlink.c:4064 1 lock held by syz-executor/16920: #0: ffffffff8f2e1fc8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8f2e1fc8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #0: ffffffff8f2e1fc8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8db/0x1c70 net/core/rtnetlink.c:4064 4 locks held by syz.2.1164/17017: #0: ffff88801d7e4d80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close net/bluetooth/hci_core.c:481 [inline] #0: ffff88801d7e4d80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x1fe/0x500 net/bluetooth/hci_core.c:2678 #1: ffff88801d7e4078 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x66a/0x1330 net/bluetooth/hci_sync.c:5213 #2: ffffffff8f4481c8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2064 [inline] #2: ffffffff8f4481c8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xa1/0x230 net/bluetooth/hci_conn.c:2534 #3: ffff88807b228b38 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x70/0x680 net/bluetooth/l2cap_core.c:1761 1 lock held by syz-executor/17020: #0: ffffffff8f2e1fc8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8f2e1fc8 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x3b0/0x18b0 net/ipv4/devinet.c:979 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-rc4-syzkaller-00147-gebd297a2affa #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: 68 Comm: kworker/u8:4 Not tainted 6.15.0-rc4-syzkaller-00147-gebd297a2affa #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025 Workqueue: writeback wb_workfn (flush-7:5) RIP: 0010:filter_irq_stacks+0x32/0xa0 kernel/stacktrace.c:397 Code: 41 55 41 54 53 85 f6 74 70 49 89 fe 41 89 f4 31 db 49 bd 00 00 00 00 00 fc ff df 49 89 ff 4c 89 f8 48 c1 e8 03 42 80 3c 28 00 <74> 08 4c 89 ff e8 d4 d7 72 00 49 8b 04 de 48 3d 30 02 00 81 0f 93 RSP: 0018:ffffc90001596590 EFLAGS: 00000246 RAX: 1ffff920002b2cce RBX: 0000000000000008 RCX: 0000000000000001 RDX: 0000000000002800 RSI: 0000000000000014 RDI: ffffc90001596630 RBP: ffffc90001596860 R08: 000000000000000f R09: 0000000000000000 R10: 0000000000000000 R11: ffffffff817199f5 R12: 0000000000000014 R13: dffffc0000000000 R14: ffffc90001596630 R15: ffffc90001596670 FS: 0000000000000000(0000) GS:ffff888126200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000056088eeed088 CR3: 000000000dd36000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: stack_depot_save_flags+0x40/0x910 lib/stackdepot.c:610 kasan_save_stack mm/kasan/common.c:48 [inline] kasan_save_track+0x4f/0x80 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:377 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:394 kasan_kmalloc include/linux/kasan.h:260 [inline] __kmalloc_cache_noprof+0x230/0x3d0 mm/slub.c:4372 kmalloc_noprof include/linux/slab.h:905 [inline] slab_free_hook mm/slub.c:2350 [inline] slab_free mm/slub.c:4656 [inline] kmem_cache_free+0x169/0x3f0 mm/slub.c:4758 f2fs_submit_page_read+0x116/0x190 fs/f2fs/data.c:1113 f2fs_get_read_data_folio+0x393/0x690 fs/f2fs/data.c:1271 f2fs_get_lock_data_folio+0x54/0x1f0 fs/f2fs/data.c:1322 move_data_page fs/f2fs/gc.c:1457 [inline] gc_data_segment fs/f2fs/gc.c:1681 [inline] do_garbage_collect+0x37d0/0x78c0 fs/f2fs/gc.c:1825 f2fs_gc+0xc69/0x2540 fs/f2fs/gc.c:1929 f2fs_balance_fs+0x55b/0x780 fs/f2fs/segment.c:456 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