------------[ cut here ]------------
WARNING: CPU: 0 PID: 21621 at lib/idr.c:157 idr_replace+0x1d8/0x240 lib/idr.c:157
Kernel panic - not syncing: panic_on_warn set ...

CPU: 0 PID: 21621 Comm: syz-executor1 Not tainted 4.13.0-rc5-next-20170817+ #5
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:16 [inline]
 dump_stack+0x194/0x257 lib/dump_stack.c:52
 panic+0x1e4/0x417 kernel/panic.c:180
 __warn+0x1c4/0x1d9 kernel/panic.c:541
 report_bug+0x211/0x2d0 lib/bug.c:183
 fixup_bug+0x40/0x90 arch/x86/kernel/traps.c:190
 do_trap_no_signal arch/x86/kernel/traps.c:224 [inline]
 do_trap+0x260/0x390 arch/x86/kernel/traps.c:273
 do_error_trap+0x120/0x390 arch/x86/kernel/traps.c:310
 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:323
 invalid_op+0x18/0x20 arch/x86/entry/entry_64.S:929
RIP: 0010:idr_replace+0x1d8/0x240 lib/idr.c:157
RSP: 0018:ffff880059af79f8 EFLAGS: 00010216
RAX: 0000000000010000 RBX: 1ffff1000b35ef43 RCX: ffffc90001116000
RDX: 000000000000007e RSI: ffffffff84d0b858 RDI: ffff880059af7a78
RBP: ffff880059af7ae0 R08: ffffffff8285aca7 R09: 0000000000000000
R10: ffff880059af79a8 R11: ffff88003e3c0068 R12: ffffffffffffffff
R13: ffff880059af7ab8 R14: dffffc0000000000 R15: ffff880059af7bc8
 drm_gem_handle_delete+0x33/0xa0 drivers/gpu/drm/drm_gem.c:297
 drm_gem_close_ioctl+0xa1/0xe0 drivers/gpu/drm/drm_gem.c:671
 drm_ioctl_kernel+0x1e7/0x2e0 drivers/gpu/drm/drm_ioctl.c:729
 drm_ioctl+0x72e/0xa50 drivers/gpu/drm/drm_ioctl.c:825
 vfs_ioctl fs/ioctl.c:45 [inline]
 do_vfs_ioctl+0x1b1/0x1520 fs/ioctl.c:685
 SYSC_ioctl fs/ioctl.c:700 [inline]
 SyS_ioctl+0x8f/0xc0 fs/ioctl.c:691
 entry_SYSCALL_64_fastpath+0x1f/0xbe
RIP: 0033:0x446739
RSP: 002b:00007f9c28750c08 EFLAGS: 00000282 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 0000000000446739
RDX: 000000002091aff8 RSI: 0000000040086409 RDI: 0000000000000005
RBP: 0000000000708000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000282 R12: 00000000ffffffff
R13: 0000000000005640 R14: 00000000006e7700 R15: 0000000000000000
Dumping ftrace buffer:
   (ftrace buffer empty)
Kernel Offset: disabled
Rebooting in 86400 seconds..