INFO: task syz.2.2617:11342 blocked for more than 143 seconds. Not tainted 6.12.0-rc1-syzkaller-00031-ge32cde8d2bd7 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.2617 state:D stack:23808 pid:11342 tgid:11342 ppid:5229 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5315 [inline] __schedule+0x1843/0x4ae0 kernel/sched/core.c:6675 __schedule_loop kernel/sched/core.c:6752 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6767 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6824 __mutex_lock_common kernel/locking/mutex.c:684 [inline] __mutex_lock+0x6a7/0xd70 kernel/locking/mutex.c:752 nfsd_shutdown_threads+0x4e/0xd0 fs/nfsd/nfssvc.c:625 nfsd_umount+0x43/0xd0 fs/nfsd/nfsctl.c:1428 deactivate_locked_super+0xc4/0x130 fs/super.c:473 cleanup_mnt+0x41f/0x4b0 fs/namespace.c:1373 task_work_run+0x24f/0x310 kernel/task_work.c:228 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop kernel/entry/common.c:114 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x168/0x370 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fee4697dff9 RSP: 002b:00007ffea1f93c58 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 000000000003ecfc RCX: 00007fee4697dff9 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007fee46b37a80 R08: 0000000000000001 R09: 00007ffea1f93f4f R10: 00007fee46800000 R11: 0000000000000246 R12: 000000000003ed46 R13: 00007ffea1f93d60 R14: 0000000000000032 R15: ffffffffffffffff Showing all locks held in the system: 3 locks held by kworker/0:0/8: #0: ffff88801ac80948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff88801ac80948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310 #1: ffffc900000d7d00 (deferred_process_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc900000d7d00 (deferred_process_work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310 #2: ffffffff8fcbf248 (rtnl_mutex){+.+.}-{3:3}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104 1 lock held by khungtaskd/30: #0: ffffffff8e937de0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8e937de0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8e937de0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6720 2 locks held by kworker/u8:3/52: 3 locks held by kworker/u8:5/2622: #0: ffff88802e15b948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff88802e15b948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310 #1: ffffc90009457d00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc90009457d00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310 #2: ffffffff8fcbf248 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xd0/0x16f0 net/ipv6/addrconf.c:4196 5 locks held by kworker/u8:6/2674: #0: ffff88801baeb148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff88801baeb148 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310 #1: ffffc90009807d00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc90009807d00 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310 #2: ffffffff8fcb2750 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x16a/0xcc0 net/core/net_namespace.c:580 #3: ffffffff8fcbf248 (rtnl_mutex){+.+.}-{3:3}, at: cleanup_net+0x6af/0xcc0 net/core/net_namespace.c:616 #4: ffffffff8e93d378 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:297 [inline] #4: ffffffff8e93d378 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x381/0x830 kernel/rcu/tree_exp.h:976 3 locks held by kworker/u8:7/3628: #0: ffff88801ac89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff88801ac89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310 #1: ffffc9000afa7d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc9000afa7d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310 #2: ffffffff8fcbf248 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:276 2 locks held by dhcpcd/4887: #0: ffff888059e116c8 (nlk_cb_mutex-ROUTE){+.+.}-{3:3}, at: __netlink_dump_start+0x119/0x790 net/netlink/af_netlink.c:2404 #1: ffffffff8fcbf248 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #1: ffffffff8fcbf248 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_dumpit+0x99/0x200 net/core/rtnetlink.c:6505 2 locks held by getty/4975: #0: ffff88802ec540a0 (&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+0x6a6/0x1e00 drivers/tty/n_tty.c:2211 1 lock held by syz.3.1120/7847: 2 locks held by syz.4.2515/11100: #0: ffffffff8fd24fb0 (cb_lock){++++}-{3:3}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8ec176e8 (nfsd_mutex){+.+.}-{3:3}, at: nfsd_nl_listener_set_doit+0x12d/0x1a90 fs/nfsd/nfsctl.c:1964 2 locks held by syz.2.2617/11342: #0: ffff8880617ae0e0 (&type->s_umount_key#85){++++}-{3:3}, at: __super_lock fs/super.c:56 [inline] #0: ffff8880617ae0e0 (&type->s_umount_key#85){++++}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff8880617ae0e0 (&type->s_umount_key#85){++++}-{3:3}, at: deactivate_super+0xb5/0xf0 fs/super.c:505 #1: ffffffff8ec176e8 (nfsd_mutex){+.+.}-{3:3}, at: nfsd_shutdown_threads+0x4e/0xd0 fs/nfsd/nfssvc.c:625 2 locks held by syz.1.2878/12133: #0: ffff888062ebc0e0 (&type->s_umount_key#85){++++}-{3:3}, at: __super_lock fs/super.c:56 [inline] #0: ffff888062ebc0e0 (&type->s_umount_key#85){++++}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff888062ebc0e0 (&type->s_umount_key#85){++++}-{3:3}, at: deactivate_super+0xb5/0xf0 fs/super.c:505 #1: ffffffff8ec176e8 (nfsd_mutex){+.+.}-{3:3}, at: nfsd_shutdown_threads+0x4e/0xd0 fs/nfsd/nfssvc.c:625 1 lock held by syz.3.3248/13725: #0: ffff8880617ae0e0 (&type->s_umount_key#85){++++}-{3:3}, at: __super_lock fs/super.c:58 [inline] #0: ffff8880617ae0e0 (&type->s_umount_key#85){++++}-{3:3}, at: super_lock+0x27c/0x400 fs/super.c:120 1 lock held by syz-executor/13797: #0: ffffffff8fcbf248 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #0: ffffffff8fcbf248 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6e6/0xcf0 net/core/rtnetlink.c:6643 2 locks held by syz.1.3270/13849: #0: ffff88807b190420 (sb_writers#3){.+.+}-{0:0}, at: direct_splice_actor+0x49/0x220 fs/splice.c:1163 #1: ffff8880617ae0e0 (&type->s_umount_key#85){++++}-{3:3}, at: __super_lock fs/super.c:58 [inline] #1: ffff8880617ae0e0 (&type->s_umount_key#85){++++}-{3:3}, at: super_lock+0x27c/0x400 fs/super.c:120 1 lock held by syz-executor/13864: #0: ffffffff8fcbf248 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #0: ffffffff8fcbf248 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6e6/0xcf0 net/core/rtnetlink.c:6643 2 locks held by syz-executor/13944: #0: ffffffff8fcb2750 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x328/0x570 net/core/net_namespace.c:490 #1: ffffffff8fcbf248 (rtnl_mutex){+.+.}-{3:3}, at: ip_tunnel_init_net+0x20e/0x720 net/ipv4/ip_tunnel.c:1159 1 lock held by syz-executor/13954: #0: ffffffff8fcbf248 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #0: ffffffff8fcbf248 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6e6/0xcf0 net/core/rtnetlink.c:6643 1 lock held by syz.2.3294/13989: #0: ffffffff8fcbf248 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:698 [inline] #0: ffffffff8fcbf248 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x3b/0x1b0 drivers/net/tun.c:3517 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.12.0-rc1-syzkaller-00031-ge32cde8d2bd7 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 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:162 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline] watchdog+0xff4/0x1040 kernel/hung_task.c:379 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 7847 Comm: syz.3.1120 Not tainted 6.12.0-rc1-syzkaller-00031-ge32cde8d2bd7 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:io_cqring_wait_schedule io_uring/io_uring.c:2486 [inline] RIP: 0010:io_cqring_wait io_uring/io_uring.c:2588 [inline] RIP: 0010:__do_sys_io_uring_enter io_uring/io_uring.c:3384 [inline] RIP: 0010:__se_sys_io_uring_enter+0x185d/0x2bb0 io_uring/io_uring.c:3276 Code: 89 ef be 04 00 00 00 e8 11 35 52 fd b8 01 00 00 00 41 87 45 00 48 8b 9c 24 90 00 00 00 48 8b 84 24 10 01 00 00 42 80 3c 38 00 <74> 08 48 89 df e8 49 32 52 fd 48 8b 1b 31 ff 48 89 de e8 3c a9 eb RSP: 0018:ffffc90017b9fba0 EFLAGS: 00000246 RAX: 1ffff11008484c59 RBX: ffff8880424262c8 RCX: 0000000000000001 RDX: dffffc0000000000 RSI: ffffffff8c0acac0 RDI: 0000000000000001 RBP: ffffc90017b9ff00 R08: ffffffff901bba2f R09: 1ffffffff2037745 R10: dffffc0000000000 R11: fffffbfff2037746 R12: ffff888042426000 R13: ffff8880267d5a18 R14: ffff8880424262d4 R15: dffffc0000000000 FS: 00007fc3eff866c0(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fcd48513ff8 CR3: 00000000246c4000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fc3ef17dff9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fc3eff86038 EFLAGS: 00000246 ORIG_RAX: 00000000000001aa RAX: ffffffffffffffda RBX: 00007fc3ef335f80 RCX: 00007fc3ef17dff9 RDX: 0000000000400000 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 00007fc3ef1f0296 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fc3ef335f80 R15: 00007ffee57881a8