INFO: task syz.1.578:8179 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.578 state:D stack:26312 pid:8179 tgid:8175 ppid:5831 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1190/0x5de0 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:7026 kvm_swap_active_memslots+0x2ea/0x7d0 virt/kvm/kvm_main.c:1642 kvm_activate_memslot virt/kvm/kvm_main.c:1786 [inline] kvm_create_memslot virt/kvm/kvm_main.c:1852 [inline] kvm_set_memslot+0xd3b/0x1380 virt/kvm/kvm_main.c:1964 kvm_set_memory_region+0xe53/0x1610 virt/kvm/kvm_main.c:2120 kvm_set_internal_memslot+0x9f/0xe0 virt/kvm/kvm_main.c:2143 __x86_set_memory_region+0x2f6/0x740 arch/x86/kvm/x86.c:13252 kvm_alloc_apic_access_page+0xc5/0x140 arch/x86/kvm/lapic.c:2788 vmx_vcpu_create+0x503/0xbd0 arch/x86/kvm/vmx/vmx.c:7607 kvm_arch_vcpu_create+0x688/0xb20 arch/x86/kvm/x86.c:12705 kvm_vm_ioctl_create_vcpu virt/kvm/kvm_main.c:4207 [inline] kvm_vm_ioctl+0xfec/0x3fd0 virt/kvm/kvm_main.c:5158 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+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7efcadb8f7c9 RSP: 002b:00007efcaea86038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007efcadde6180 RCX: 00007efcadb8f7c9 RDX: 0000000000000000 RSI: 000000000000ae41 RDI: 0000000000000003 RBP: 00007efcadc13f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007efcadde6218 R14: 00007efcadde6180 R15: 00007ffe4ac83bd8 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e3c45e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e3c45e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8e3c45e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6775 2 locks held by getty/5590: #0: ffff88814dc0e0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222 2 locks held by syz.1.578/8179: #0: ffff88807b97c0a8 (&kvm->slots_lock){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:228 [inline] #0: ffff88807b97c0a8 (&kvm->slots_lock){+.+.}-{4:4}, at: kvm_alloc_apic_access_page+0x27/0x140 arch/x86/kvm/lapic.c:2782 #1: ffff88807b97c138 (&kvm->slots_arch_lock){+.+.}-{4:4}, at: kvm_set_memslot+0x34/0x1380 virt/kvm/kvm_main.c:1915 1 lock held by syz.3.1064/10075: #0: ffff8880b843a4d8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x29/0x130 kernel/sched/core.c:638 3 locks held by syz.2.1096/10173: 2 locks held by syz.3.1127/10295: #0: ffffffff900eb4c8 (rtnl_mutex){+.+.}-{4:4}, at: ppp_release+0x167/0x230 drivers/net/ppp/ppp_generic.c:413 #1: ffffffff8e3cfb78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x284/0x3c0 kernel/rcu/tree_exp.h:311 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:332 [inline] watchdog+0xf3f/0x1170 kernel/hung_task.c:495 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x675/0x7d0 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245