L1TF CPU bug present and SMT on, data leak possible. See CVE-2018-3646 and https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/l1tf.html for details. ============================= WARNING: suspicious RCU usage 5.15.104-syzkaller #0 Not tainted ----------------------------- include/linux/kvm_host.h:880 suspicious rcu_dereference_check() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 1 lock held by syz-executor272/3583: #0: ffff888023cf40c8 (&vcpu->mutex){+.+.}-{3:3}, at: kvm_vcpu_ioctl+0x1d4/0xcf0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3840 stack backtrace: CPU: 1 PID: 3583 Comm: syz-executor272 Not tainted 5.15.104-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/02/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106 __kvm_memslots include/linux/kvm_host.h:878 [inline] kvm_vcpu_memslots+0x1b7/0x200 include/linux/kvm_host.h:892 kvm_vcpu_gfn_to_memslot+0x2b/0x390 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2140 kvm_vcpu_unmap+0x5d/0x80 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2755 nested_vmx_vmexit+0x1451/0x2b50 arch/x86/kvm/vmx/nested.c:4662 vmx_leave_nested+0x7d/0xb0 arch/x86/kvm/vmx/nested.c:6322 kvm_leave_nested arch/x86/kvm/x86.c:618 [inline] kvm_vcpu_ioctl_x86_set_vcpu_events+0x8d8/0x10e0 arch/x86/kvm/x86.c:4793 kvm_arch_vcpu_ioctl+0x120e/0x1d40 arch/x86/kvm/x86.c:5278 kvm_vcpu_ioctl+0x6db/0xcf0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:4019 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:874 [inline] __se_sys_ioctl+0xf1/0x160 fs/ioctl.c:860 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7feb3d7f9ed9 Code: 28 c3 e8 2a 14 00 00 66 2e 0f 1f 84 00 00 00 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 c0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fff7fd5cd28 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007feb3d7f9ed9 RDX: 00000000200000c0 RSI: 000000004040aea0 RDI: 0000000000000005 RBP: 00007feb3d7bd9d0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007feb3d7bda60 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000