refcount_t: increment on 0; use-after-free.
WARNING: CPU: 1 PID: 27279 at lib/refcount.c:153 refcount_inc_checked lib/refcount.c:153 [inline]
WARNING: CPU: 1 PID: 27279 at lib/refcount.c:153 refcount_inc_checked+0x61/0x70 lib/refcount.c:151
Kernel panic - not syncing: panic_on_warn set ...
kobject: 'kvm' (000000004ca56886): kobject_uevent_env
CPU: 1 PID: 27279 Comm: syz-executor4 Not tainted 5.0.0-rc2+ #30
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+0x1db/0x2d0 lib/dump_stack.c:113
kobject: 'kvm' (000000004ca56886): fill_kobj_path: path = '/devices/virtual/misc/kvm'
 panic+0x2cb/0x65c kernel/panic.c:214
 __warn.cold+0x20/0x48 kernel/panic.c:571
 report_bug+0x263/0x2b0 lib/bug.c:186
 fixup_bug arch/x86/kernel/traps.c:178 [inline]
 fixup_bug arch/x86/kernel/traps.c:173 [inline]
 do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:271
 do_invalid_op+0x37/0x50 arch/x86/kernel/traps.c:290
 invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:973
RIP: 0010:refcount_inc_checked lib/refcount.c:153 [inline]
RIP: 0010:refcount_inc_checked+0x61/0x70 lib/refcount.c:151
Code: 1d 6c 4d c8 06 31 ff 89 de e8 db 3e f2 fd 84 db 75 dd e8 92 3d f2 fd 48 c7 c7 a0 95 81 88 c6 05 4c 4d c8 06 01 e8 3f 8c bb fd <0f> 0b eb c1 90 66 2e 0f 1f 84 00 00 00 00 00 55 48 89 e5 41 54 49
RSP: 0018:ffff88804ea8f7f8 EFLAGS: 00010286
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffc9000e66f000
RDX: 000000000001031e RSI: ffffffff81685456 RDI: 0000000000000005
RBP: ffff88804ea8f808 R08: ffff88804f73c080 R09: ffffed1015ce5021
R10: ffffed1015ce5020 R11: ffff8880ae728107 R12: ffffc9000193c6b8
R13: ffff888084996800 R14: ffffffff898bdf60 R15: ffffc90001933000
 kvm_get_kvm arch/x86/kvm/../../../virt/kvm/kvm_main.c:762 [inline]
 kvm_ioctl_create_device arch/x86/kvm/../../../virt/kvm/kvm_main.c:3012 [inline]
 kvm_vm_ioctl+0x117f/0x1fe0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3250
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:509 [inline]
 do_vfs_ioctl+0x107b/0x17d0 fs/ioctl.c:696
 ksys_ioctl+0xab/0xd0 fs/ioctl.c:713
 __do_sys_ioctl fs/ioctl.c:720 [inline]
 __se_sys_ioctl fs/ioctl.c:718 [inline]
 __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:718
 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x458099
Code: 6d b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 3b b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f1ce427ec78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000458099
RDX: 0000000020000340 RSI: 00000000c00caee0 RDI: 0000000000000007
RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f1ce427f6d4
R13: 00000000004c0b92 R14: 00000000004d2770 R15: 00000000ffffffff
Kernel Offset: disabled
Rebooting in 86400 seconds..