Additional info:
reporter:       libreport-2.3.0
WARNING: CPU: 1 PID: 278 at drivers/gpu/drm/qxl/qxl_ttm.c:414 qxl_sync_obj_wait+0x188/0x210 [qxl]()
sync obj 301 still has outstanding releases 0 0 0 4096 1
Modules linked in: rpcsec_gss_krb5 auth_rpcgss nfsv4 dns_resolver nfs lockd sunrpc fscache cfg80211 rfkill xfs libcrc32c btrfs snd_hda_codec_generic xor snd_hda_intel snd_hda_controller snd_hda_codec snd_hwdep snd_seq snd_seq_device raid6_pq ppdev crct10dif_pclmul snd_pcm crc32_pclmul crc32c_intel ghash_clmulni_intel joydev snd_timer snd parport_pc serio_raw virtio_console virtio_balloon soundcore parport i2c_piix4 pvpanic qxl drm_kms_helper ttm virtio_net virtio_scsi virtio_blk drm virtio_pci virtio_ring virtio ata_generic pata_acpi
CPU: 1 PID: 278 Comm: plymouthd Not tainted 3.17.6-300.fc21.x86_64 #1
Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
 0000000000000000 000000008bc70f7c ffff8800367fb738 ffffffff8173f8aa
 ffff8800367fb780 ffff8800367fb770 ffffffff810970bd 0000000000000001
 ffff8800b99f4360 0000000000000001 ffff8800b99f4378 0000000000000000
Call Trace:
 [<ffffffff8173f8aa>] dump_stack+0x45/0x56
 [<ffffffff810970bd>] warn_slowpath_common+0x7d/0xa0
 [<ffffffff8109713c>] warn_slowpath_fmt+0x5c/0x80
 [<ffffffff81745be3>] ? schedule_hrtimeout_range+0x13/0x20
 [<ffffffffa00cf1e8>] qxl_sync_obj_wait+0x188/0x210 [qxl]
 [<ffffffffa009773d>] ttm_bo_wait+0xad/0x1b0 [ttm]
 [<ffffffff810c7668>] ? __enqueue_entity+0x78/0x80
 [<ffffffffa0099399>] ttm_bo_evict+0x59/0x3a0 [ttm]
 [<ffffffffa005982e>] ? drm_mm_insert_node_in_range_generic+0x28e/0x3a0 [drm]
 [<ffffffffa009980d>] ttm_mem_evict_first+0x12d/0x1c0 [ttm]
 [<ffffffffa0099b65>] ttm_bo_mem_space+0x2c5/0x350 [ttm]
 [<ffffffffa009a082>] ttm_bo_validate+0x1d2/0x250 [ttm]
 [<ffffffffa009a369>] ttm_bo_init+0x269/0x3c0 [ttm]
 [<ffffffffa00d13af>] qxl_bo_create+0x13f/0x1b0 [qxl]
 [<ffffffffa00d1120>] ? qxl_fbdev_qobj_is_fb+0x30/0x30 [qxl]
 [<ffffffffa00d27f6>] qxl_alloc_bo_reserved+0x46/0xc0 [qxl]
 [<ffffffffa00d36ab>] qxl_image_alloc_objects+0xab/0x150 [qxl]
 [<ffffffffa00d41aa>] qxl_draw_dirty_fb+0x15a/0x470 [qxl]
 [<ffffffffa0069ed9>] ? drm_modeset_lock_all_crtcs+0x49/0x70 [drm]
 [<ffffffffa00ccda1>] qxl_framebuffer_surface_dirty+0xa1/0xf0 [qxl]
 [<ffffffff811ee6a2>] ? __kmalloc+0x242/0x260
 [<ffffffffa005f9e5>] drm_mode_dirtyfb_ioctl+0x145/0x170 [drm]
 [<ffffffffa0050e6f>] drm_ioctl+0x1df/0x680 [drm]
 [<ffffffff812531c5>] ? ep_poll+0x295/0x440
 [<ffffffff81220910>] do_vfs_ioctl+0x2d0/0x4b0
 [<ffffffff810c2860>] ? wake_up_state+0x20/0x20
 [<ffffffff81220b71>] SyS_ioctl+0x81/0xa0
 [<ffffffff81746a69>] system_call_fastpath+0x16/0x1b

Potential duplicate: bug 1050142