INFO: task syz-executor:6356 blocked for more than 143 seconds. Not tainted 6.6.95-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:21704 pid:6356 ppid:1 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x14e2/0x4580 kernel/sched/core.c:6700 schedule+0xbd/0x170 kernel/sched/core.c:6774 wb_wait_for_completion+0x166/0x290 fs/fs-writeback.c:192 sync_inodes_sb+0x1bc/0x9e0 fs/fs-writeback.c:2761 sync_filesystem+0x171/0x220 fs/sync.c:64 generic_shutdown_super+0x6f/0x2b0 fs/super.c:666 kill_block_super+0x44/0x90 fs/super.c:1660 deactivate_locked_super+0x97/0x100 fs/super.c:481 cleanup_mnt+0x429/0x4c0 fs/namespace.c:1250 task_work_run+0x1ce/0x250 kernel/task_work.c:239 exit_task_work include/linux/task_work.h:43 [inline] do_exit+0x90b/0x23c0 kernel/exit.c:883 do_group_exit+0x21b/0x2d0 kernel/exit.c:1024 __do_sys_exit_group kernel/exit.c:1035 [inline] __se_sys_exit_group kernel/exit.c:1033 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1033 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f5525b8e929 RSP: 002b:00007ffe6355b148 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 00007f5525c109a9 RCX: 00007f5525b8e929 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001 RBP: 0000000000000027 R08: 00007ffe63558ee6 R09: 00007ffe6355c400 R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffe6355c400 R13: 00007f5525c10925 R14: 0000555557c474a8 R15: 00007ffe6355e5c0 Showing all locks held in the system: 4 locks held by kworker/u4:0/11: #0: ffff888017873938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #0: ffff888017873938 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #1: ffffc90000107d00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #1: ffffc90000107d00 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #2: ffffffff8dfa1ed0 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x136/0xb90 net/core/net_namespace.c:606 #3: ffffffff8dfaecc8 (rtnl_mutex){+.+.}-{3:3}, at: default_device_exit_batch+0xe9/0xa60 net/core/dev.c:11594 1 lock held by khungtaskd/29: #0: ffffffff8cd2f760 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #0: ffffffff8cd2f760 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #0: ffffffff8cd2f760 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633 2 locks held by kworker/u4:2/42: #0: ffff88801a642938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #0: ffff88801a642938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #1: ffffc90000b2fd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #1: ffffc90000b2fd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 2 locks held by kworker/1:2/55: #0: ffff888017872538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #0: ffff888017872538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #1: ffffc9000130fd00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #1: ffffc9000130fd00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 3 locks held by kworker/u4:4/77: #0: ffff888017871538 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #0: ffff888017871538 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #1: ffffc900020afd00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #1: ffffc900020afd00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #2: ffffffff8dfaecc8 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:286 1 lock held by dhcpcd/5437: #0: ffffffff8dfaecc8 (rtnl_mutex){+.+.}-{3:3}, at: devinet_ioctl+0x32c/0x1c60 net/ipv4/devinet.c:1102 2 locks held by getty/5534: #0: ffff8880319410a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000325e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x425/0x1380 drivers/tty/n_tty.c:2217 3 locks held by kworker/1:4/5818: #0: ffff888017870938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #0: ffff888017870938 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #1: ffffc9000488fd00 (deferred_process_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #1: ffffc9000488fd00 (deferred_process_work){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #2: ffffffff8dfaecc8 (rtnl_mutex){+.+.}-{3:3}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104 2 locks held by syz-executor/6356: #0: ffff88802653c0e0 (&type->s_umount_key#75){++++}-{3:3}, at: __super_lock fs/super.c:56 [inline] #0: ffff88802653c0e0 (&type->s_umount_key#75){++++}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff88802653c0e0 (&type->s_umount_key#75){++++}-{3:3}, at: deactivate_super+0xa4/0xe0 fs/super.c:513 #1: ffff888140f4e7d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:364 [inline] #1: ffff888140f4e7d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x1a0/0x9e0 fs/fs-writeback.c:2759 1 lock held by segctord/6907: 2 locks held by syz-executor/8936: #0: ffffffff8dfa1ed0 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x351/0x5e0 net/core/net_namespace.c:516 #1: ffffffff8dfaecc8 (rtnl_mutex){+.+.}-{3:3}, at: wg_netns_pre_exit+0x1c/0x1d0 drivers/net/wireguard/device.c:422 2 locks held by syz-executor/8939: #0: ffffffff8dfa1ed0 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x351/0x5e0 net/core/net_namespace.c:516 #1: ffffffff8dfaecc8 (rtnl_mutex){+.+.}-{3:3}, at: setup_net+0x6a3/0xa00 net/core/net_namespace.c:365 1 lock held by syz.1.443/8950: #0: ffffffff8dfaecc8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline] #0: ffffffff8dfaecc8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x76f/0xf10 net/core/rtnetlink.c:6472 1 lock held by syz.1.443/8953: #0: ffffffff8dfaecc8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline] #0: ffffffff8dfaecc8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x76f/0xf10 net/core/rtnetlink.c:6472 1 lock held by syz.1.443/8954: #0: ffffffff8dfaecc8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline] #0: ffffffff8dfaecc8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x76f/0xf10 net/core/rtnetlink.c:6472 1 lock held by syz-executor/8963: #0: ffffffff8dfaecc8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline] #0: ffffffff8dfaecc8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x76f/0xf10 net/core/rtnetlink.c:6472 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 29 Comm: khungtaskd Not tainted 6.6.95-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106 nmi_cpu_backtrace+0x39b/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x2f0 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+0xf41/0xf80 kernel/hung_task.c:379 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 6907 Comm: segctord Not tainted 6.6.95-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:check_region_inline mm/kasan/generic.c:169 [inline] RIP: 0010:kasan_check_range+0x14/0x290 mm/kasan/generic.c:187 Code: b8 ea ff ff ff c3 0f 0b b8 ea ff ff ff c3 cc cc cc cc cc cc cc cc 66 0f 1f 00 b0 01 48 85 f6 0f 84 b8 01 00 00 55 41 57 41 56 <41> 55 41 54 53 4c 8d 04 37 49 39 f8 0f 82 5a 02 00 00 49 89 f9 49 RSP: 0018:ffffc900043cfb20 EFLAGS: 00000202 RAX: 00000000ffffff01 RBX: ffff88802f68f150 RCX: ffffffff81684972 RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffff88802f68f150 RBP: ffffc900043cfbf8 R08: dffffc0000000000 R09: 1ffffffff21b0ac0 R10: dffffc0000000000 R11: fffffbfff21b0ac1 R12: ffff88802f68f160 R13: ffff88802f68f158 R14: 1ffff11005ed1e2c R15: 1ffff11005ed1e2b FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fff08b11fac CR3: 000000000cb30000 CR4: 00000000003506f0 Call Trace: instrument_atomic_read_write include/linux/instrumented.h:96 [inline] atomic_try_cmpxchg_acquire include/linux/atomic/atomic-instrumented.h:1294 [inline] queued_spin_lock include/asm-generic/qspinlock.h:111 [inline] do_raw_spin_lock+0x112/0x2c0 kernel/locking/spinlock_debug.c:115 spin_lock include/linux/spinlock.h:351 [inline] nilfs_segctor_notify fs/nilfs2/segment.c:2417 [inline] nilfs_segctor_construct+0x393/0x690 fs/nilfs2/segment.c:2474 nilfs_segctor_thread_construct fs/nilfs2/segment.c:2562 [inline] nilfs_segctor_thread+0x4f6/0x1000 fs/nilfs2/segment.c:2646 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293