INFO: task syz.3.3230:18997 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.3230 state:D stack:25312 pid:18997 tgid:18996 ppid:18423 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5260 [inline] __schedule+0x14ea/0x5050 kernel/sched/core.c:6867 __schedule_loop kernel/sched/core.c:6949 [inline] schedule+0x164/0x360 kernel/sched/core.c:6964 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7021 __mutex_lock_common kernel/locking/mutex.c:692 [inline] __mutex_lock+0x7fe/0x1300 kernel/locking/mutex.c:776 nfsd_nl_version_get_doit+0x17c/0xc40 fs/nfsd/nfsctl.c:1811 genl_family_rcv_msg_doit+0x22a/0x330 net/netlink/genetlink.c:1115 genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline] genl_rcv_msg+0x61c/0x7a0 net/netlink/genetlink.c:1210 netlink_rcv_skb+0x232/0x4b0 net/netlink/af_netlink.c:2550 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x80f/0x9b0 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg net/socket.c:742 [inline] ____sys_sendmsg+0xa68/0xad0 net/socket.c:2592 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2646 __sys_sendmsg net/socket.c:2678 [inline] __do_sys_sendmsg net/socket.c:2683 [inline] __se_sys_sendmsg net/socket.c:2681 [inline] __x64_sys_sendmsg+0x1bd/0x2a0 net/socket.c:2681 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ffa43f9aeb9 RSP: 002b:00007ffa44ee2028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007ffa44215fa0 RCX: 00007ffa43f9aeb9 RDX: 0000000000000000 RSI: 00002000000032c0 RDI: 0000000000000005 RBP: 00007ffa44008c1f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffa44216038 R14: 00007ffa44215fa0 R15: 00007fff70f5d108 Showing all locks held in the system: 3 locks held by rcu_exp_gp_kthr/18: #0: ffff8880b863a918 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:639 #1: ffff8880b8624588 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880 kernel/sched/psi.c:933 #2: ffff88807b93c768 (&p->pi_lock){-.-.}-{2:2}, at: class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:557 [inline] #2: ffff88807b93c768 (&p->pi_lock){-.-.}-{2:2}, at: try_to_wake_up+0x66/0x1380 kernel/sched/core.c:4106 1 lock held by khungtaskd/31: #0: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by getty/5580: #0: ffff88814e2910a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900036c62f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13c0 drivers/tty/n_tty.c:2211 3 locks held by kworker/u8:28/10996: #0: ffff88813fe69948 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff88813fe69948 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3340 #1: ffffc90004a3fbc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc90004a3fbc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3340 #2: ffffffff8f9abf08 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:313 2 locks held by syz.1.2288/15053: #0: ffffffff8fa19af0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8e879428 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x141/0x16c0 fs/nfsd/nfsctl.c:1886 1 lock held by udevd/18428: #0: ffff888025394358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:962 2 locks held by syz.3.3230/18997: #0: ffffffff8fa19af0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8e879428 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_version_get_doit+0x17c/0xc40 fs/nfsd/nfsctl.c:1811 2 locks held by syz.4.4193/22646: #0: ffffffff8f99d690 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x4f7/0x730 net/core/net_namespace.c:577 #1: ffffffff8f705a90 (rdma_nets_rwsem){++++}-{4:4}, at: rdma_dev_exit_net+0x92/0x350 drivers/infiniband/core/device.c:1159 5 locks held by syz.4.4193/22647: #0: ffffffff8f99d690 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x4f7/0x730 net/core/net_namespace.c:577 #1: ffffffff8f7058d0 (devices_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x200/0x2f0 drivers/infiniband/core/device.c:1215 #2: ffffffff8f705a90 (rdma_nets_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x238/0x2f0 drivers/infiniband/core/device.c:1220 #3: ffff8880345d8f98 (&device->compat_devs_mutex){+.+.}-{4:4}, at: add_one_compat_dev+0xf0/0x650 drivers/infiniband/core/device.c:979 #4: ffffffff8f9abf08 (rtnl_mutex){+.+.}-{4:4}, at: ib_get_eth_speed+0x173/0x7f0 drivers/infiniband/core/verbs.c:1998 3 locks held by syz.0.4205/22686: #0: ffffffff8f99d690 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x4f7/0x730 net/core/net_namespace.c:577 #1: ffffffff8f7058d0 (devices_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x200/0x2f0 drivers/infiniband/core/device.c:1215 #2: ffffffff8f705a90 (rdma_nets_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x238/0x2f0 drivers/infiniband/core/device.c:1220 1 lock held by syz.2.4215/22719: #0: ffffffff8f9abf08 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline] #0: ffffffff8f9abf08 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3436 3 locks held by syz.6.4223/22752: #0: ffffffff8ff14dd8 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8ff14dd8 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8ff14dd8 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570 #1: ffffffff8f9abf08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8f9abf08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff8f9abf08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8a1/0x1be0 net/core/rtnetlink.c:4071 #2: ffffffff8e560c78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline] #2: ffffffff8e560c78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2d0/0x770 kernel/rcu/tree_exp.h:956 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:161 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x135/0x170 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline] watchdog+0xf90/0xfe0 kernel/hung_task.c:515 kthread+0x726/0x8b0 kernel/kthread.c:463 ret_from_fork+0x51b/0xa40 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 22686 Comm: syz.0.4205 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026 RIP: 0010:deref_stack_reg arch/x86/kernel/unwind_orc.c:422 [inline] RIP: 0010:unwind_next_frame+0xbfd/0x23c0 arch/x86/kernel/unwind_orc.c:588 Code: 0f 97 c2 20 c2 20 ca 80 fa 01 0f 85 31 0e 00 00 48 8d 43 08 4c 39 f8 0f 97 c1 4c 39 e0 0f 96 c0 20 c8 3c 01 0f 85 17 0e 00 00 <48> 89 df e8 0b 24 00 00 49 89 c4 48 8b 34 24 48 8d 5e 01 48 bd 00 RSP: 0018:ffffc90000007778 EFLAGS: 00000002 RAX: ffffc90000008001 RBX: ffffc90000007ff8 RCX: 1ffff92000000f01 RDX: ffffffff9129ac22 RSI: ffffffff9129ac26 RDI: ffffffff8c0739a0 RBP: 1ffff92000000f0b R08: 000000000000000e R09: ffffffff8e55a360 R10: ffffc90000007898 R11: ffffffff81af9170 R12: 1ffff92000000f0a R13: ffffc90000008000 R14: ffffc90000007848 R15: ffffc90000000000 FS: 00007f5e3edd56c0(0000) GS:ffff8881256ea000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f871bbe12f8 CR3: 0000000036a6e000 CR4: 00000000003526f0 Call Trace: arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 kasan_save_stack+0x3e/0x60 mm/kasan/common.c:57 kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556 insert_work+0x3d/0x330 kernel/workqueue.c:2180 __queue_work+0xccf/0xf90 kernel/workqueue.c:2335 call_timer_fn+0x192/0x5a0 kernel/time/timer.c:1748 expire_timers kernel/time/timer.c:1794 [inline] __run_timers kernel/time/timer.c:2373 [inline] __run_timer_base+0x67e/0x8b0 kernel/time/timer.c:2385 run_timer_base kernel/time/timer.c:2394 [inline] run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2404 handle_softirqs+0x22a/0x7c0 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0x5f/0x150 kernel/softirq.c:723 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1056 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:console_trylock_spinning kernel/printk/printk.c:2037 [inline] RIP: 0010:vprintk_emit+0x45d/0x560 kernel/printk/printk.c:2425 Code: 0f 84 44 ff ff ff e8 e2 45 21 00 fb eb 44 e8 da 45 21 00 e8 a5 fd f4 09 4d 85 f6 74 94 e8 cb 45 21 00 fb 48 c7 c7 60 c7 54 8e <31> f6 ba 01 00 00 00 31 c9 41 b8 01 00 00 00 45 31 c9 53 e8 3b 1b RSP: 0018:ffffc9001b7974a0 EFLAGS: 00000246 RAX: ffffffff81a31185 RBX: ffffffff81a30fff RCX: 0000000000080000 RDX: ffffc9000cb7c000 RSI: 000000000007ffff RDI: ffffffff8e54c760 RBP: ffffc9001b797550 R08: ffffffff8fef4977 R09: 1ffffffff1fde92e R10: dffffc0000000000 R11: fffffbfff1fde92f R12: 0000000000000000 R13: 000000000000002f R14: 0000000000000200 R15: 1ffff920036f2e98 _printk+0xdd/0x130 kernel/printk/printk.c:2451 ib_get_eth_speed+0x468/0x7f0 drivers/infiniband/core/verbs.c:2009 siw_query_port+0x3c/0x4a0 drivers/infiniband/sw/siw/siw_verbs.c:179 ib_setup_port_attrs+0x26e/0x2140 drivers/infiniband/core/sysfs.c:1429 add_one_compat_dev+0x448/0x650 drivers/infiniband/core/device.c:1005 rdma_dev_init_net+0x243/0x2f0 drivers/infiniband/core/device.c:1221 ops_init+0x35c/0x5c0 net/core/net_namespace.c:137 setup_net+0x118/0x340 net/core/net_namespace.c:446 copy_net_ns+0x50e/0x730 net/core/net_namespace.c:581 create_new_namespaces+0x3e7/0x6a0 kernel/nsproxy.c:130 unshare_nsproxy_namespaces+0x11a/0x160 kernel/nsproxy.c:226 ksys_unshare+0x4f4/0x900 kernel/fork.c:3171 __do_sys_unshare kernel/fork.c:3242 [inline] __se_sys_unshare kernel/fork.c:3240 [inline] __x64_sys_unshare+0x38/0x50 kernel/fork.c:3240 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f5e40b9aeb9 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f5e3edd5028 EFLAGS: 00000246 ORIG_RAX: 0000000000000110 RAX: ffffffffffffffda RBX: 00007f5e40e16090 RCX: 00007f5e40b9aeb9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000006a040000 RBP: 00007f5e40c08c1f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f5e40e16128 R14: 00007f5e40e16090 R15: 00007fff21c73dc8