Description of problem:
unknown

Additional info:
reporter:       libreport-2.3.0
kernel BUG at drivers/gpu/drm/drm_crtc.c:536!
invalid opcode: 0000 [#1] SMP 
Modules linked in: binfmt_misc fuse bnep bluetooth tun ip6t_rpfilter ip6t_REJECT nf_reject_ipv6 xt_conntrack ebtable_nat ebtable_broute bridge stp llc ebtable_filter ebtables ip6table_nat nf_conntrack_ipv6 nf_defrag_ipv6 nf_nat_ipv6 ip6table_mangle ip6table_security ip6table_raw ip6table_filter ip6_tables iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack iptable_mangle iptable_security iptable_raw arc4 brcmsmac cordic brcmutil b43 mac80211 cfg80211 dell_laptop ssb rfkill dcdbas iTCO_wdt intel_rapl iosf_mbi iTCO_vendor_support dell_wmi ppdev sparse_keymap x86_pkg_temp_thermal snd_hda_codec_hdmi coretemp kvm_intel snd_hda_codec_idt snd_hda_codec_generic kvm i8k snd_hda_intel snd_hda_controller joydev snd_hda_codec serio_raw snd_hwdep snd_seq sdhci_pci snd_seq_device
 sdhci hid_logitech_hidpp snd_pcm mmc_core lpc_ich parport_pc mei_me snd_timer parport dell_smo8800 bcma mfd_core i2c_i801 wmi mei snd shpchp soundcore nfsd auth_rpcgss nfs_acl lockd grace sunrpc dm_crypt uas usb_storage i915 crct10dif_pclmul crc32_pclmul crc32c_intel i2c_algo_bit ghash_clmulni_intel drm_kms_helper tg3 drm ptp pps_core hid_logitech_dj video
CPU: 2 PID: 1476 Comm: Xorg.bin Not tainted 3.19.3-200.fc21.x86_64 #1
Hardware name: Dell Inc. Latitude E5430 non-vPro/0MYF02, BIOS A12 08/07/2013
task: ffff8802004f9360 ti: ffff8800d88e0000 task.ti: ffff8800d88e0000
RIP: 0010:[<ffffffffa0048439>]  [<ffffffffa0048439>] drm_framebuffer_free_bug+0x9/0x10 [drm]
RSP: 0000:ffff8800d88e3b18  EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff880214691000 RCX: 0000000000000000
RDX: 0000000000000040 RSI: 0000000000000000 RDI: ffff8801314e63c8
RBP: ffff8800d88e3b18 R08: ffff880174e65770 R09: 0000000000000000
R10: ffff8800316a9880 R11: ffff880213890800 R12: ffff8801314e63c0
R13: ffff880211c03000 R14: ffff880036a28378 R15: ffff880036a28088
FS:  00007f3f72c159c0(0000) GS:ffff88021e300000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000012adf20 CR3: 00000000d8019000 CR4: 00000000001407e0
Stack:
 ffff8800d88e3b38 ffffffffa004a32d ffff880214691000 ffff880036a28000
 ffff8800d88e3b78 ffffffffa00dbe01 ffff880036a280d0 ffff880211c03000
 ffff880036a28000 ffff8802138918d0 ffff8802138918c8 ffff880036a28088
Call Trace:
 [<ffffffffa004a32d>] drm_plane_force_disable+0x9d/0xd0 [drm]
 [<ffffffffa00dbe01>] restore_fbdev_mode+0x51/0xf0 [drm_kms_helper]
 [<ffffffffa00dded9>] drm_fb_helper_restore_fbdev_mode_unlocked+0x29/0x80 [drm_kms_helper]
 [<ffffffffa019220e>] intel_fbdev_restore_mode+0x1e/0x50 [i915]
 [<ffffffffa01b77ee>] i915_driver_lastclose+0xe/0x20 [i915]
 [<ffffffffa003cd0e>] drm_lastclose+0x2e/0x150 [drm]
 [<ffffffffa003d0f8>] drm_release+0x2c8/0x4b0 [drm]
 [<ffffffff8121b5af>] __fput+0xdf/0x1f0
 [<ffffffff8121b70e>] ____fput+0xe/0x10
 [<ffffffff810b8a94>] task_work_run+0xd4/0xf0
 [<ffffffff8109e492>] do_exit+0x302/0xa70
 [<ffffffffa01357b5>] ? i915_gem_execbuffer2+0x1b5/0x2b0 [i915]
 [<ffffffff8109ec95>] do_group_exit+0x45/0xb0
 [<ffffffff810aa74c>] get_signal+0x27c/0x610
 [<ffffffff81014527>] do_signal+0x37/0x750
 [<ffffffff8122e298>] ? do_vfs_ioctl+0x2f8/0x500
 [<ffffffff81014ca9>] do_notify_resume+0x69/0xb0
 [<ffffffff81774ca7>] int_signal+0x12/0x17
Code: a3 72 e1 4c 89 e7 e8 17 20 1b e1 48 83 c4 08 5b 41 5c 41 5d 5d c3 66 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 55 48 89 e5 <0f> 0b 0f 1f 44 00 00 0f 1f 44 00 00 55 48 89 e5 53 48 89 fb 48 
RIP  [<ffffffffa0048439>] drm_framebuffer_free_bug+0x9/0x10 [drm]
 RSP <ffff8800d88e3b18>
vpnagentd[1437]: segfault at 0 ip           (null) sp 00007fff8d24a320 error 14 in vpnagentd[400000+a0000]

Potential duplicate: bug 1205650