------------[ cut here ]------------
WARNING: CPU: 2 PID: 19899 at drivers/gpu/drm/drm_modeset_lock.c:97 drm_modeset_lock_all+0x1fa/0x2d0 drivers/gpu/drm/drm_modeset_lock.c:97
Kernel panic - not syncing: panic_on_warn set ...

CPU: 2 PID: 19899 Comm: syz-executor5 Not tainted 4.14.0-rc5-next-20171018+ #8
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+0x1e4/0x41c kernel/panic.c:183
 __warn+0x1c4/0x1e0 kernel/panic.c:546
 report_bug+0x211/0x2d0 lib/bug.c:183
 fixup_bug+0x40/0x90 arch/x86/kernel/traps.c:177
 do_trap_no_signal arch/x86/kernel/traps.c:211 [inline]
 do_trap+0x260/0x390 arch/x86/kernel/traps.c:260
 do_error_trap+0x120/0x390 arch/x86/kernel/traps.c:297
 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:310
 invalid_op+0x18/0x20 arch/x86/entry/entry_64.S:905
RIP: 0010:drm_modeset_lock_all+0x1fa/0x2d0 drivers/gpu/drm/drm_modeset_lock.c:97
RSP: 0018:ffff88005ad7f808 EFLAGS: 00010216
RAX: 0000000000010000 RBX: ffff88006bb404c0 RCX: ffffffff829aef2a
RDX: 000000000000ed4f RSI: ffffc900026f2000 RDI: 0000000000000282
RBP: ffff88005ad7f820 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: ffff88003ca76280 R14: ffff88006bb404c8 R15: 0000000000000000
 pan_display_legacy drivers/gpu/drm/drm_fb_helper.c:1660 [inline]
 drm_fb_helper_pan_display+0x59b/0xa30 drivers/gpu/drm/drm_fb_helper.c:1704
 fb_pan_display+0x2a3/0x640 drivers/video/fbdev/core/fbmem.c:911
 do_fb_ioctl+0x692/0xc80 drivers/video/fbdev/core/fbmem.c:1157
 fb_ioctl+0xdd/0x120 drivers/video/fbdev/core/fbmem.c:1235
 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
 do_syscall_64+0x26c/0x8d0 arch/x86/entry/common.c:287
 entry_SYSCALL64_slow_path+0x25/0x25
RIP: 0033:0x447c89
RSP: 002b:00007f9b94bb7bd8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f9b94bb86cc RCX: 0000000000447c89
RDX: 0000000020008ff0 RSI: 0000000000004606 RDI: 0000000000000013
RBP: 0000000000748020 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000014
R13: 0000000000003558 R14: 00000000006e75f8 R15: 0000000000000001
Dumping ftrace buffer:
   (ftrace buffer empty)
Kernel Offset: disabled
Rebooting in 86400 seconds..