Additional info:
reporter:       libreport-2.6.4
BUG: unable to handle kernel NULL pointer dereference at 0000000000000060
IP: [<ffffffff817814cc>] _raw_spin_lock+0xc/0x30
PGD 1c88ba067 PUD 1c8aef067 PMD 0 
Oops: 0002 [#1] SMP 
Modules linked in: mptctl mptbase nfnetlink_queue nfnetlink_log nfnetlink bluetooth rfkill ip6t_rt nf_conntrack_ftp ip6t_REJECT nf_reject_ipv6 xt_limit nf_conntrack_ipv6 nf_defrag_ipv6 nf_conntrack_ipv4 nf_defrag_ipv4 xt_connlimit xt_multiport xt_recent xt_conntrack nf_conntrack ip6table_filter ip6_tables intel_rapl iosf_mbi x86_pkg_temp_thermal coretemp kvm_intel hpwdt kvm hpilo joydev iTCO_wdt iTCO_vendor_support ie31200_edac crct10dif_pclmul crc32_pclmul crc32c_intel shpchp edac_core pcc_cpufreq ipmi_ssif lpc_ich ipmi_si acpi_cpufreq ipmi_msghandler tpm_tis acpi_power_meter tpm binfmt_misc mgag200 i2c_algo_bit drm_kms_helper ttm drm tg3 serio_raw ptp hpsa pps_core fjes
CPU: 4 PID: 6283 Comm: plymouthd Not tainted 4.3.4-200.fc22.x86_64 #1
Hardware name: HP ProLiant DL320e Gen8 v2, BIOS P80 04/02/2015
task: ffff8800ec600000 ti: ffff8801d72a0000 task.ti: ffff8801d72a0000
RIP: 0010:[<ffffffff817814cc>]  [<ffffffff817814cc>] _raw_spin_lock+0xc/0x30
RSP: 0018:ffff8801d72a3938  EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000001
RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000000000000060
RBP: ffff8801d72a3958 R08: 0000000000000000 R09: ffff8801fe3e7680
R10: ffff8801fe3e7680 R11: 0000000000000000 R12: 0000000000000000
R13: ffff8801fe10b028 R14: ffff8801fe10f800 R15: 0000000000000001
FS:  00007f78ad127700(0000) GS:ffff880202300000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000060 CR3: 00000001c8873000 CR4: 00000000001406e0
Stack:
 ffffffffa00ab6bf 0000000000000141 ffff8801fc93b800 0000000000000000
 ffff8801d72a3a48 ffffffffa007a60c ffff8800ec600000 0000000000000000
 ffffffff820029c0 ffff8801e6de32c0 ffff8801d72a3ab8 ffff8801fc93b800
Call Trace:
 [<ffffffffa00ab6bf>] ? drm_gem_object_lookup+0x1f/0xa0 [drm]
 [<ffffffffa007a60c>] mga_crtc_cursor_set+0xdc/0xab0 [mgag200]
 [<ffffffff813bab85>] ? find_next_bit+0x15/0x20
 [<ffffffff813a5fe1>] ? cpumask_next_and+0x31/0x50
 [<ffffffff8177f399>] ? __ww_mutex_lock+0x19/0xa0
 [<ffffffffa00c6011>] ? drm_modeset_lock+0x81/0xd0 [drm]
 [<ffffffffa01368b6>] restore_fbdev_mode+0xf6/0x110 [drm_kms_helper]
 [<ffffffffa0138735>] drm_fb_helper_restore_fbdev_mode_unlocked+0x25/0x70 [drm_kms_helper]
 [<ffffffffa01387ad>] drm_fb_helper_set_par+0x2d/0x50 [drm_kms_helper]
 [<ffffffff8141cfe6>] fb_set_var+0x236/0x460
 [<ffffffff8141318f>] fbcon_blank+0x30f/0x350
 [<ffffffff81497d03>] do_unblank_screen+0xd3/0x1a0
 [<ffffffff8148d44a>] vt_ioctl+0x50a/0x12e0
 [<ffffffff817807ce>] ? schedule_hrtimeout_range_clock.part.23+0xbe/0x150
 [<ffffffff81480a4a>] tty_ioctl+0x35a/0xc00
 [<ffffffff810146f1>] ? __switch_to+0x261/0x4b0
 [<ffffffff8133572c>] ? ioctl_has_perm+0xbc/0xf0
 [<ffffffff81236bd5>] do_vfs_ioctl+0x295/0x470
 [<ffffffff813357b0>] ? selinux_file_ioctl+0x50/0xd0
 [<ffffffff813298e3>] ? security_file_ioctl+0x43/0x60
 [<ffffffff81236e29>] SyS_ioctl+0x79/0x90
 [<ffffffff81003c35>] ? syscall_return_slowpath+0x55/0x150
 [<ffffffff8178182e>] entry_SYSCALL_64_fastpath+0x12/0x71
Code: 00 00 f0 0f b1 17 85 c0 75 01 c3 55 89 c6 48 89 e5 e8 e9 7b 96 ff 5d c3 0f 1f 80 00 00 00 00 0f 1f 44 00 00 31 c0 ba 01 00 00 00 <f0> 0f b1 17 85 c0 75 01 c3 55 89 c6 48 89 e5 e8 c0 7b 96 ff 5d 
RIP  [<ffffffff817814cc>] _raw_spin_lock+0xc/0x30
 RSP <ffff8801d72a3938>