INFO: task syz.2.365:7762 blocked for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.365 state:D stack:25720 pid:7762 tgid:7761 ppid:5833 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x1139/0x6150 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6960 kvm_swap_active_memslots+0x2ea/0x7d0 virt/kvm/kvm_main.c:1643 kvm_activate_memslot virt/kvm/kvm_main.c:1787 [inline] kvm_create_memslot virt/kvm/kvm_main.c:1853 [inline] kvm_set_memslot+0xd84/0x1450 virt/kvm/kvm_main.c:1965 kvm_set_memory_region+0xe4a/0x15e0 virt/kvm/kvm_main.c:2121 kvm_set_internal_memslot+0x9f/0xe0 virt/kvm/kvm_main.c:2144 __x86_set_memory_region+0x2f6/0x740 arch/x86/kvm/x86.c:13278 kvm_alloc_apic_access_page+0xc5/0x140 arch/x86/kvm/lapic.c:2806 vmx_vcpu_create+0x503/0xbd0 arch/x86/kvm/vmx/vmx.c:7646 kvm_arch_vcpu_create+0x688/0xb20 arch/x86/kvm/x86.c:12726 kvm_vm_ioctl_create_vcpu virt/kvm/kvm_main.c:4208 [inline] kvm_vm_ioctl+0x105e/0x4090 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+0xcd/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd036d8f7c9 RSP: 002b:00007fd034fee038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fd036fe5fa0 RCX: 00007fd036d8f7c9 RDX: 0000000000000000 RSI: 000000000000ae41 RDI: 0000000000000003 RBP: 00007fd036e13f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fd036fe6038 R14: 00007fd036fe5fa0 R15: 00007ffc41f9d3b8 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e3c94a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e3c94a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8e3c94a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6775 2 locks held by getty/6130: #0: ffff888033dd00a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc900043fd2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x1510 drivers/tty/n_tty.c:2211 4 locks held by kworker/u8:23/7351: #0: ffff88813ff69948 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work+0x128d/0x1b20 kernel/workqueue.c:3232 #1: ffffc9000b71fc90 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x914/0x1b20 kernel/workqueue.c:3233 #2: ffffffff90144ea8 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0x51/0xc0 net/core/link_watch.c:303 #3: ffffffff8e3d4bf8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x284/0x3c0 kernel/rcu/tree_exp.h:311 2 locks held by syz.2.365/7762: #0: ffff88814eb4c0a8 (&kvm->slots_lock){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline] #0: ffff88814eb4c0a8 (&kvm->slots_lock){+.+.}-{4:4}, at: kvm_alloc_apic_access_page+0x27/0x140 arch/x86/kvm/lapic.c:2800 #1: ffff88814eb4c138 (&kvm->slots_arch_lock){+.+.}-{4:4}, at: kvm_set_memslot+0x34/0x1450 virt/kvm/kvm_main.c:1916 1 lock held by syz.1.794/10104: #0: ffffffff90144ea8 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline] #0: ffffffff90144ea8 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x38/0x230 drivers/net/tun.c:3436 2 locks held by syz.0.839/10271: #0: ffffffff9012e6d0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x333/0x7c0 net/core/net_namespace.c:577 #1: ffffffff90144ea8 (rtnl_mutex){+.+.}-{4:4}, at: fib6_rules_net_exit_batch+0x15/0xe0 net/ipv6/fib6_rules.c:641 2 locks held by syz.4.840/10276: #0: ffffffff9012e6d0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x333/0x7c0 net/core/net_namespace.c:577 #1: ffffffff90144ea8 (rtnl_mutex){+.+.}-{4:4}, at: caif_exit_net+0x64/0x3c0 net/caif/caif_dev.c:528 1 lock held by syz-executor/10273: #0: ffffffff8e3d4bf8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x1a3/0x3c0 kernel/rcu/tree_exp.h:343 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP 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] __sys_info lib/sys_info.c:157 [inline] sys_info+0x133/0x180 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline] watchdog+0xe66/0x1180 kernel/hung_task.c:515 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 10299 Comm: syz.5.844 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:26 [inline] RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:109 [inline] RIP: 0010:check_preemption_disabled+0x2d/0xe0 lib/smp_processor_id.c:19 Code: 53 48 83 ec 08 65 8b 1d d5 c1 3c 08 65 8b 05 ca c1 3c 08 a9 ff ff ff 7f 74 0f 48 83 c4 08 89 d8 5b 5d 41 5c c3 cc cc cc cc 9c <58> f6 c4 02 74 ea 48 89 fd 65 48 8b 05 8a c1 3c 08 f6 40 2f 04 74 RSP: 0018:ffffc900033a75f8 EFLAGS: 00000046 RAX: 0000000080000000 RBX: 0000000000000001 RCX: ffffc900033a7634 RDX: 0000000000000000 RSI: ffffffff8daa411c RDI: ffffffff8bf2b480 RBP: 0000000000000001 R08: 0000000000000001 R09: 00000000ffffffff R10: 0000000000000002 R11: 0000000000007d3c R12: ffffffff816c79a4 R13: 0000000000000206 R14: ffff88802f918000 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8881249fd000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f7300ae9f98 CR3: 000000000e184000 CR4: 00000000003526f0 Call Trace: lockdep_recursion_finish kernel/locking/lockdep.c:470 [inline] lock_release+0x153/0x2d0 kernel/locking/lockdep.c:5891 rcu_lock_release include/linux/rcupdate.h:341 [inline] rcu_read_unlock include/linux/rcupdate.h:897 [inline] class_rcu_destructor include/linux/rcupdate.h:1195 [inline] unwind_next_frame+0x3f9/0x20a0 arch/x86/kernel/unwind_orc.c:479 arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 save_stack+0x160/0x1f0 mm/page_owner.c:165 __reset_page_owner+0x84/0x1a0 mm/page_owner.c:320 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1395 [inline] __free_frozen_pages+0x7df/0x1170 mm/page_alloc.c:2943 vfree+0x1fd/0xb50 mm/vmalloc.c:3466 kcov_put kernel/kcov.c:439 [inline] kcov_put kernel/kcov.c:435 [inline] kcov_close+0x34/0x60 kernel/kcov.c:535 __fput+0x402/0xb70 fs/file_table.c:468 task_work_run+0x150/0x240 kernel/task_work.c:233 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x87f/0x2bd0 kernel/exit.c:971 do_group_exit+0xd3/0x2a0 kernel/exit.c:1112 get_signal+0x2671/0x26d0 kernel/signal.c:3034 arch_do_signal_or_restart+0x8f/0x7a0 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:41 [inline] exit_to_user_mode_loop+0x8c/0x540 kernel/entry/common.c:75 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline] do_syscall_64+0x4ee/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f72ffb8f7c9 Code: Unable to access opcode bytes at 0x7f72ffb8f79f. RSP: 002b:00007f7300b0b038 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 RAX: 0000000000000002 RBX: 00007f72ffde5fa0 RCX: 00007f72ffb8f7c9 RDX: 0000000000000007 RSI: 0000200000000200 RDI: 0000000000000003 RBP: 00007f72ffc13f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000004008 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f72ffde6038 R14: 00007f72ffde5fa0 R15: 00007ffc5fbf7978