INFO: task syz.5.3968:14271 blocked for more than 143 seconds. Not tainted 6.16.0-rc3-syzkaller-00837-g28aa52b6189f #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.5.3968 state:D stack:27528 pid:14271 tgid:14270 ppid:13186 task_flags:0x400040 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x16f5/0x4d00 kernel/sched/core.c:6785 __schedule_loop kernel/sched/core.c:6863 [inline] schedule+0x165/0x360 kernel/sched/core.c:6878 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6935 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0x724/0xe80 kernel/locking/mutex.c:747 nfsd_nl_listener_get_doit+0x10a/0x5e0 fs/nfsd/nfsctl.c:2076 genl_family_rcv_msg_doit+0x215/0x300 net/netlink/genetlink.c:1115 genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline] genl_rcv_msg+0x60e/0x790 net/netlink/genetlink.c:1210 netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2534 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219 netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline] netlink_unicast+0x75b/0x8d0 net/netlink/af_netlink.c:1339 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1883 sock_sendmsg_nosec net/socket.c:714 [inline] __sock_sendmsg+0x219/0x270 net/socket.c:729 ____sys_sendmsg+0x505/0x830 net/socket.c:2614 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2668 __sys_sendmsg net/socket.c:2700 [inline] __do_sys_sendmsg net/socket.c:2705 [inline] __se_sys_sendmsg net/socket.c:2703 [inline] __x64_sys_sendmsg+0x19b/0x260 net/socket.c:2703 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f8327b8e929 RSP: 002b:00007f8328ac2038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f8327db5fa0 RCX: 00007f8327b8e929 RDX: 0000000000000010 RSI: 0000200000001540 RDI: 0000000000000003 RBP: 00007f8327c10b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f8327db5fa0 R15: 00007ffc131ba108 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e13ee60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e13ee60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e13ee60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770 4 locks held by kworker/u8:3/43: 2 locks held by getty/5590: #0: ffff888034f920a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 1 lock held by syz-executor/5850: 3 locks held by kworker/0:4/5904: 2 locks held by kworker/0:5/5925: #0: ffff88801a480d48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801a480d48 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321 #1: ffffc90004ef7bc0 (free_ipc_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc90004ef7bc0 (free_ipc_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321 2 locks held by syz.1.3148/12430: #0: ffffffff8f5777f0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8e41cf48 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x12a/0x1650 fs/nfsd/nfsctl.c:1922 2 locks held by syz.5.3968/14271: #0: ffffffff8f5777f0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8e41cf48 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_get_doit+0x10a/0x5e0 fs/nfsd/nfsctl.c:2076 4 locks held by syz-executor/15021: 2 locks held by syz.0.6913/20455: #0: ffffffff8f5777f0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8e41cf48 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x12a/0x1650 fs/nfsd/nfsctl.c:1922 2 locks held by dhcpcd/21270: #0: ffff888059f85c08 (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:869 [inline] #0: ffff888059f85c08 (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: __sock_release net/socket.c:648 [inline] #0: ffff888059f85c08 (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: sock_close+0x9b/0x240 net/socket.c:1439 #1: ffffffff8e144978 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:336 [inline] #1: ffffffff8e144978 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:998 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc3-syzkaller-00837-g28aa52b6189f #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 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:307 [inline] watchdog+0xfee/0x1030 kernel/hung_task.c:470 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 21271 Comm: kworker/0:0 Not tainted 6.16.0-rc3-syzkaller-00837-g28aa52b6189f #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Workqueue: events destroy_super_work RIP: 0010:__bfs kernel/locking/lockdep.c:1818 [inline] RIP: 0010:__bfs_backwards kernel/locking/lockdep.c:1863 [inline] RIP: 0010:check_irq_usage kernel/locking/lockdep.c:2799 [inline] RIP: 0010:check_prev_add kernel/locking/lockdep.c:3172 [inline] RIP: 0010:check_prevs_add kernel/locking/lockdep.c:3287 [inline] RIP: 0010:validate_chain+0xfd7/0x2140 kernel/locking/lockdep.c:3911 Code: 25 ff 0f 00 00 39 05 d4 bf 06 12 73 06 89 05 cc bf 06 12 49 8b 04 24 48 89 de 48 39 e8 0f 84 33 fe ff ff 4c 89 68 30 48 8b 00 <48> 39 e8 75 f4 48 89 de e9 1f fe ff ff 48 c7 c7 70 fd 00 8e 48 89 RSP: 0018:ffffc90003a17608 EFLAGS: 00000002 RAX: ffffffff963b6908 RBX: 0000000000000155 RCX: 0000000000000004 RDX: 0000000000000008 RSI: 0000000000000155 RDI: ffff888052871e00 RBP: ffffffff93466df8 R08: ffffc90003a175d0 R09: 0000000000000020 R10: dffffc0000000000 R11: ffffffff819e9310 R12: ffffffff9628cd88 R13: ffffffff9628cdf8 R14: ffff888052872968 R15: 0000000000000003 FS: 0000000000000000(0000) GS:ffff888125c48000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffeaf23c4b8 CR3: 000000000df38000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5240 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 class_raw_spinlock_constructor include/linux/spinlock.h:535 [inline] pcpu_free lib/debugobjects.c:311 [inline] __free_object+0x260/0x6c0 lib/debugobjects.c:521 __debug_check_no_obj_freed lib/debugobjects.c:1104 [inline] debug_check_no_obj_freed+0x1dc/0x470 lib/debugobjects.c:1129 slab_free_hook mm/slub.c:2312 [inline] slab_free mm/slub.c:4643 [inline] kfree+0x112/0x440 mm/slub.c:4842 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3321 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245