Description of problem:
Install f21-(rawhide) 

Additional info:
reporter:       libreport-2.1.12
WARNING: CPU: 0 PID: 1015 at mm/slub.c:1007 deactivate_slab+0x4e0/0x590()
Modules linked in: 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 snd_intel8x0 snd_ac97_codec ppdev ac97_bus snd_seq joydev snd_seq_device snd_pcm microcode serio_raw snd_timer i2c_piix4 parport_pc snd parport i2c_core soundcore nfsd auth_rpcgss nfs_acl lockd isofs squashfs e1000 ata_generic pata_acpi sunrpc loop
CPU: 0 PID: 1015 Comm: rpm Not tainted 3.14.0-0.rc1.git0.2.fc21.x86_64 #1
Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
 0000000000000000 000000003bbf1f0e ffff880036129ad8 ffffffff817cef2d
 0000000000000000 ffff880036129b10 ffffffff810967cd 0000000000000002
 ffff88003d431f00 ffff88003d43c780 0000000000000000 ffffea0000dc3340
Call Trace:
 [<ffffffff817cef2d>] dump_stack+0x4d/0x66
 [<ffffffff810967cd>] warn_slowpath_common+0x7d/0xa0
 [<ffffffff810968fa>] warn_slowpath_null+0x1a/0x20
 [<ffffffff8120d850>] deactivate_slab+0x4e0/0x590
 [<ffffffff81202140>] ? alloc_pages_current+0x120/0x210
 [<ffffffff8120ba8d>] ? new_slab+0x2dd/0x390
 [<ffffffff8120b9e6>] ? new_slab+0x236/0x390
 [<ffffffff817cd1ef>] __slab_alloc+0x392/0x5a7
 [<ffffffff81210d74>] ? kmem_cache_alloc+0x264/0x300
 [<ffffffff81234fc1>] ? get_empty_filp+0x61/0x240
 [<ffffffff81210d74>] kmem_cache_alloc+0x264/0x300
 [<ffffffff81234fc1>] ? get_empty_filp+0x61/0x240
 [<ffffffff81234fc1>] get_empty_filp+0x61/0x240
 [<ffffffff810dd26d>] ? sched_clock_local+0x1d/0x80
 [<ffffffff812448bd>] path_openat+0x4d/0x6c0
 [<ffffffff810dd26d>] ? sched_clock_local+0x1d/0x80
 [<ffffffff810dd26d>] ? sched_clock_local+0x1d/0x80
 [<ffffffff812457ad>] do_filp_open+0x4d/0xb0
 [<ffffffff810f5d4f>] ? lock_release_holdtime.part.29+0xf/0x190
 [<ffffffff817d8097>] ? _raw_spin_unlock+0x27/0x40
 [<ffffffff8125549f>] ? __alloc_fd+0xaf/0x1f0
 [<ffffffff81232197>] do_sys_open+0x137/0x240
 [<ffffffff812322be>] SyS_open+0x1e/0x20
 [<ffffffff817e2da9>] system_call_fastpath+0x16/0x1b