INFO: task syz.0.425:7375 blocked for more than 143 seconds. Not tainted 6.13.0-syzkaller-04117-g9e6c4e6b605c #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.425 state:D stack:25984 pid:7375 tgid:7371 ppid:5855 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5373 [inline] __schedule+0x186c/0x4be0 kernel/sched/core.c:6760 __schedule_loop kernel/sched/core.c:6837 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6852 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6909 __mutex_lock_common kernel/locking/mutex.c:662 [inline] __mutex_lock+0x817/0x1010 kernel/locking/mutex.c:730 nfsd_nl_listener_get_doit+0x115/0x5e0 fs/nfsd/nfsctl.c:2121 genl_family_rcv_msg_doit net/netlink/genetlink.c:1115 [inline] genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline] genl_rcv_msg+0xb14/0xec0 net/netlink/genetlink.c:1210 netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2543 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219 netlink_unicast_kernel net/netlink/af_netlink.c:1322 [inline] netlink_unicast+0x7f6/0x990 net/netlink/af_netlink.c:1348 netlink_sendmsg+0x8e4/0xcb0 net/netlink/af_netlink.c:1892 sock_sendmsg_nosec net/socket.c:713 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:728 ____sys_sendmsg+0x52a/0x7e0 net/socket.c:2568 ___sys_sendmsg net/socket.c:2622 [inline] __sys_sendmsg+0x269/0x350 net/socket.c:2654 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: 0033:0x7f6cba98cda9 RSP: 002b:00007f6cbb882038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f6cbaba5fa0 RCX: 00007f6cba98cda9 RDX: 0000000024000100 RSI: 0000000020001740 RDI: 0000000000000003 RBP: 00007f6cbaa0e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f6cbaba5fa0 R15: 00007ffd6a8de328 Showing all locks held in the system: 1 lock held by khungtaskd/30: #0: ffffffff8e93a3e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8e93a3e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8e93a3e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6746 3 locks held by kworker/u8:7/1152: #0: ffff88801ac89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff88801ac89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1840 kernel/workqueue.c:3317 #1: ffffc90003f2fc60 ((work_completion)(&map->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc90003f2fc60 ((work_completion)(&map->work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1840 kernel/workqueue.c:3317 #2: ffffffff8e93f8b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:334 [inline] #2: ffffffff8e93f8b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x451/0x830 kernel/rcu/tree_exp.h:996 2 locks held by getty/5595: #0: ffff888035f490a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90002fde2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x6a6/0x1e00 drivers/tty/n_tty.c:2211 2 locks held by syz.3.242/6723: #0: ffffffff8fd298b0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8ec07548 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x12d/0x1a90 fs/nfsd/nfsctl.c:1964 2 locks held by syz.0.425/7375: #0: ffffffff8fd298b0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8ec07548 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_get_doit+0x115/0x5e0 fs/nfsd/nfsctl.c:2121 2 locks held by syz.1.1030/9355: #0: ffffffff8fd298b0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8ec07548 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x12d/0x1a90 fs/nfsd/nfsctl.c:1964 2 locks held by syz.4.1170/9810: #0: ffffffff8fd298b0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8ec07548 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_get_doit+0x1c5/0x7b0 fs/nfsd/nfsctl.c:1755 2 locks held by syz.6.1576/11177: #0: ffffffff8fd298b0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8ec07548 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_get_doit+0x1c5/0x7b0 fs/nfsd/nfsctl.c:1755 2 locks held by syz.7.1676/11497: #0: ffffffff8fcc5c08 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:702 [inline] #0: ffffffff8fcc5c08 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3b/0x1b0 drivers/net/tun.c:3521 #1: ffffffff8e93f8b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:302 [inline] #1: ffffffff8e93f8b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x381/0x830 kernel/rcu/tree_exp.h:996 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.13.0-syzkaller-04117-g9e6c4e6b605c #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 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:234 [inline] watchdog+0xff6/0x1040 kernel/hung_task.c:397 kthread+0x7a9/0x920 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148 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 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline] NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:106 [inline] NMI backtrace for cpu 1 skipped: idling at acpi_safe_halt+0x21/0x30 drivers/acpi/processor_idle.c:111