INFO: task syz.5.5524:30872 blocked for more than 143 seconds. Tainted: G U W L XTNJ syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.5.5524 state:D stack:26072 pid:30872 tgid:30865 ppid:25431 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0xfee/0x6120 kernel/sched/core.c:6911 __schedule_loop kernel/sched/core.c:6993 [inline] schedule+0xdd/0x390 kernel/sched/core.c:7008 kvm_swap_active_memslots+0x2e0/0x7c0 virt/kvm/kvm_main.c:1627 kvm_activate_memslot virt/kvm/kvm_main.c:1786 [inline] kvm_create_memslot virt/kvm/kvm_main.c:1852 [inline] kvm_set_memslot+0xbde/0x1740 virt/kvm/kvm_main.c:1964 kvm_set_memory_region+0xe1c/0x1570 virt/kvm/kvm_main.c:2120 kvm_set_internal_memslot+0x9f/0xf0 virt/kvm/kvm_main.c:2143 __x86_set_memory_region+0x2f6/0x730 arch/x86/kvm/x86.c:13355 kvm_alloc_apic_access_page+0xc5/0x140 arch/x86/kvm/lapic.c:2861 vmx_vcpu_create+0x79b/0xb90 arch/x86/kvm/vmx/vmx.c:7830 kvm_arch_vcpu_create+0x683/0xac0 arch/x86/kvm/x86.c:12803 kvm_vm_ioctl_create_vcpu virt/kvm/kvm_main.c:4207 [inline] kvm_vm_ioctl+0x756/0x4080 virt/kvm/kvm_main.c:5165 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl fs/ioctl.c:583 [inline] __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff47199c819 RSP: 002b:00007ff4727df028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007ff471c16360 RCX: 00007ff47199c819 RDX: 0000000000000004 RSI: 000000000000ae41 RDI: 0000000000000003 RBP: 00007ff471a32c91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ff471c163f8 R14: 00007ff471c16360 R15: 00007ffd71b1e2a8 Showing all locks held in the system: 1 lock held by pool_workqueue_/3: #0: ffffffff8e7f32b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x19e/0x3c0 kernel/rcu/tree_exp.h:343 1 lock held by khungtaskd/30: #0: ffffffff8e7e7760 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8e7e7760 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8e7e7760 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775 1 lock held by udevd/5195: 6 locks held by kworker/u10:10/26531: #0: ffff88801c6b6948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x1310/0x19a0 kernel/workqueue.c:3251 #1: ffffc90003cbfd08 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x988/0x19a0 kernel/workqueue.c:3252 #2: ffffffff905fe850 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xb8/0x920 net/core/net_namespace.c:675 #3: ffffffff906170a8 (rtnl_mutex){+.+.}-{4:4}, at: caif_exit_net+0x60/0x3a0 net/caif/caif_dev.c:528 #4: ffff8880376ae080 (&caifn->caifdevs.lock){+.+.}-{4:4}, at: caif_exit_net+0x77/0x3a0 net/caif/caif_dev.c:529 #5: ffffffff8e7f32b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x19e/0x3c0 kernel/rcu/tree_exp.h:343 2 locks held by syz-executor/27058: 3 locks held by kworker/0:7/27552: #0: ffff88813fe63148 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x1310/0x19a0 kernel/workqueue.c:3251 #1: ffffc90004737d08 ((fqdir_free_work).work){+.+.}-{0:0}, at: process_one_work+0x988/0x19a0 kernel/workqueue.c:3252 #2: ffffffff8e7f3180 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x48/0x6d0 kernel/rcu/tree.c:3828 2 locks held by syz.5.5524/30872: #0: ffff88805e9640a8 (&kvm->slots_lock){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline] #0: ffff88805e9640a8 (&kvm->slots_lock){+.+.}-{4:4}, at: kvm_alloc_apic_access_page+0x27/0x140 arch/x86/kvm/lapic.c:2855 #1: ffff88805e964138 (&kvm->slots_arch_lock){+.+.}-{4:4}, at: kvm_set_memslot+0x34/0x1740 virt/kvm/kvm_main.c:1915 3 locks held by syz.2.5911/32678: 2 locks held by syz.1.5919/32709: 2 locks held by syz.2.5940/32764: #0: ffffffff905fe850 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x451/0x7c0 net/core/net_namespace.c:577 #1: ffffffff906170a8 (rtnl_mutex){+.+.}-{4:4}, at: fib6_rules_net_exit_batch+0x15/0xe0 net/ipv6/fib6_rules.c:641 2 locks held by syz.6.5935/317: #0: ffffffff905fe850 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x451/0x7c0 net/core/net_namespace.c:577 #1: ffffffff906170a8 (rtnl_mutex){+.+.}-{4:4}, at: ip_tunnel_init_net+0x21e/0x780 net/ipv4/ip_tunnel.c:1146 1 lock held by syz.9.5939/329: #0: ffffffff8e7f3180 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x48/0x6d0 kernel/rcu/tree.c:3828 2 locks held by syz.9.5939/330: #0: ffffffff905fe850 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x451/0x7c0 net/core/net_namespace.c:577 #1: ffffffff906170a8 (rtnl_mutex){+.+.}-{4:4}, at: register_nexthop_notifier+0x1b/0x70 net/ipv4/nexthop.c:3976 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Tainted: G U W L XTNJ syzkaller #0 PREEMPT(full) Tainted: [U]=USER, [W]=WARN, [L]=SOFTLOCKUP, [X]=AUX, [T]=RANDSTRUCT, [N]=TEST, [J]=FWCTL Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x1d7/0x230 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+0x141/0x190 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline] watchdog+0xd25/0x1050 kernel/hung_task.c:515 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245