L1TF CPU bug present and SMT on, data leak possible. See CVE-2018-3646 and https://www.kernel.org/doc/html/latest/admin-guide/l1tf.html for details.
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refcount_t: increment on 0; use-after-free.
WARNING: CPU: 0 PID: 12014 at lib/refcount.c:153 refcount_inc_checked+0x5d/0x70 lib/refcount.c:153
Kernel panic - not syncing: panic_on_warn set ...
kobject: 'kvm' (00000000653b8b5d): kobject_uevent_env
CPU: 0 PID: 12014 Comm: syz-executor5 Not tainted 4.20.0-rc5+ #265
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x244/0x39d lib/dump_stack.c:113
 panic+0x2ad/0x55c kernel/panic.c:188
kobject: 'kvm' (00000000653b8b5d): fill_kobj_path: path = '/devices/virtual/misc/kvm'
 __warn.cold.8+0x20/0x45 kernel/panic.c:540
 report_bug+0x254/0x2d0 lib/bug.c:186
kobject: 'kvm' (00000000653b8b5d): kobject_uevent_env
 fixup_bug arch/x86/kernel/traps.c:178 [inline]
 do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:271
 do_invalid_op+0x36/0x40 arch/x86/kernel/traps.c:290
 invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:969
RIP: 0010:refcount_inc_checked+0x5d/0x70 lib/refcount.c:153
kobject: 'kvm' (00000000653b8b5d): fill_kobj_path: path = '/devices/virtual/misc/kvm'
Code: 1d 00 32 80 06 31 ff 89 de e8 df 08 ed fd 84 db 75 df e8 06 08 ed fd 48 c7 c7 e0 b7 60 88 c6 05 e0 31 80 06 01 e8 03 68 b6 fd <0f> 0b eb c3 0f 1f 44 00 00 66 2e 0f 1f 84 00 00 00 00 00 55 48 89
RSP: 0018:ffff8881c1e6f780 EFLAGS: 00010286
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff8165fbe5 RDI: 0000000000000005
RBP: ffff8881c1e6f788 R08: ffff8881d702c400 R09: ffffed103b5c5020
R10: ffffed103b5c5020 R11: ffff8881dae28107 R12: 0000000020000340
R13: ffff8881c1e6f838 R14: ffffffff894b6e20 R15: ffff8881bddee500
 kvm_get_kvm arch/x86/kvm/../../../virt/kvm/kvm_main.c:763 [inline]
 kvm_ioctl_create_device arch/x86/kvm/../../../virt/kvm/kvm_main.c:2930 [inline]
 kvm_vm_ioctl+0xedf/0x1d60 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3122
 kvm_vm_compat_ioctl+0x143/0x430 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3178
 __do_compat_sys_ioctl fs/compat_ioctl.c:1052 [inline]
 __se_compat_sys_ioctl fs/compat_ioctl.c:998 [inline]
 __ia32_compat_sys_ioctl+0x20e/0x630 fs/compat_ioctl.c:998
 do_syscall_32_irqs_on arch/x86/entry/common.c:326 [inline]
 do_fast_syscall_32+0x34d/0xfb2 arch/x86/entry/common.c:397
 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139
RIP: 0023:0xf7fbea29
Code: 85 d2 74 02 89 0a 5b 5d c3 8b 04 24 c3 8b 14 24 c3 8b 3c 24 c3 90 90 90 90 90 90 90 90 90 90 90 90 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 eb 0d 90 90 90 90 90 90 90 90 90 90 90 90
RSP: 002b:00000000f7fba0cc EFLAGS: 00000296 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000007 RCX: 00000000c00caee0
RDX: 0000000020000340 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
Kernel Offset: disabled
Rebooting in 86400 seconds..