------------[ cut here ]------------
WARNING: CPU: 1 PID: 9404 at drivers/gpu/drm/vkms/vkms_gem.c:37 vkms_gem_free_object+0x92/0xb0 drivers/gpu/drm/vkms/vkms_gem.c:37
Kernel panic - not syncing: panic_on_warn set ...
CPU: 1 PID: 9404 Comm: syz-executor903 Not tainted 5.5.0-rc2-next-20191218-syzkaller #0
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+0x197/0x210 lib/dump_stack.c:118
 panic+0x2e3/0x75c kernel/panic.c:221
 __warn.cold+0x2f/0x3e kernel/panic.c:582
 report_bug+0x289/0x300 lib/bug.c:195
 fixup_bug arch/x86/kernel/traps.c:174 [inline]
 fixup_bug arch/x86/kernel/traps.c:169 [inline]
 do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:267
 do_invalid_op+0x37/0x50 arch/x86/kernel/traps.c:286
 invalid_op+0x23/0x30 arch/x86/entry/entry_64.S:1027
RIP: 0010:vkms_gem_free_object+0x92/0xb0 drivers/gpu/drm/vkms/vkms_gem.c:37
Code: a4 08 24 fd 49 8d bc 24 00 02 00 00 e8 d7 c6 08 fd 4c 89 e7 e8 5f 0d aa ff 4c 89 e7 e8 27 a3 61 fd 41 5c 5d c3 e8 7e 08 24 fd <0f> 0b eb a2 e8 75 08 24 fd 0f 0b eb c8 e8 7c f2 61 fd eb b6 e8 75
RSP: 0018:ffffc90001f979f0 EFLAGS: 00010293
RAX: ffff8880a6468440 RBX: ffffffff8a00c540 RCX: ffffffff83fb6567
RDX: 0000000000000000 RSI: ffffffff845144e2 RDI: ffff8880a0121280
RBP: ffffc90001f979f8 R08: ffff8880a6468440 R09: ffffed1014024201
R10: ffffed1014024200 R11: ffff8880a0121003 R12: ffff8880a0121000
R13: ffff8880a271c000 R14: ffffffff84514450 R15: ffff8880a271c020
 drm_gem_object_free+0x100/0x220 drivers/gpu/drm/drm_gem.c:983
 kref_put include/linux/kref.h:65 [inline]
 drm_gem_object_put_unlocked drivers/gpu/drm/drm_gem.c:1017 [inline]
 drm_gem_object_put_unlocked+0x196/0x1c0 drivers/gpu/drm/drm_gem.c:1002
 drm_gem_object_handle_put_unlocked+0x1ad/0x2d0 drivers/gpu/drm/drm_gem.c:239
 drm_gem_object_release_handle+0x102/0x1c0 drivers/gpu/drm/drm_gem.c:261
 idr_for_each+0x138/0x250 lib/idr.c:208
 drm_gem_release+0x27/0x40 drivers/gpu/drm/drm_gem.c:939
 drm_file_free.part.0+0x7f4/0xc00 drivers/gpu/drm/drm_file.c:246
 drm_file_free drivers/gpu/drm/drm_file.c:215 [inline]
 drm_close_helper drivers/gpu/drm/drm_file.c:273 [inline]
 drm_release+0x286/0x3f0 drivers/gpu/drm/drm_file.c:445
 __fput+0x2ff/0x890 fs/file_table.c:280
 ____fput+0x16/0x20 fs/file_table.c:313
 task_work_run+0x145/0x1c0 kernel/task_work.c:113
 exit_task_work include/linux/task_work.h:22 [inline]
 do_exit+0x909/0x2f20 kernel/exit.c:797
 do_group_exit+0x135/0x360 kernel/exit.c:895
 __do_sys_exit_group kernel/exit.c:906 [inline]
 __se_sys_exit_group kernel/exit.c:904 [inline]
 __x64_sys_exit_group+0x44/0x50 kernel/exit.c:904
 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x442bb8
Code: Bad RIP value.
RSP: 002b:00007ffc6a0e9a68 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000442bb8
RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000
RBP: 00000000004c24c8 R08: 00000000000000e7 R09: ffffffffffffffd0
R10: 00000000004002e0 R11: 0000000000000246 R12: 0000000000000001
R13: 00000000006d41a0 R14: 0000000000000000 R15: 0000000000000000
Kernel Offset: disabled
Rebooting in 86400 seconds..