BUG: Bad page map in process xfdesktop  pte:347e5ea724d8d93b pmd:0008f067
addr:00007f548d23b000 vm_flags:08000071 anon_vma:          (null) mapping:ffff880068356980 index:618b
vma->vm_ops->fault: filemap_fault+0x0/0x3e0
vma->vm_file->f_op->mmap: generic_file_mmap+0x0/0x60
Pid: 6832, comm: xfdesktop Tainted: P    B      O 3.2.0-20-generic #32-Ubuntu
Call Trace:
 [<ffffffff81139bb9>] print_bad_pte+0x1d9/0x270
 [<ffffffff8113b5dc>] vm_normal_page+0x7c/0x80
 [<ffffffff8113c48b>] zap_pte_range+0x13b/0x3c0
 [<ffffffff8113c8ba>] unmap_page_range+0x1aa/0x2f0
 [<ffffffff8113cf8a>] unmap_vmas+0xca/0x160
 [<ffffffff81132971>] ? kzfree+0x31/0x40
 [<ffffffff81141ac9>] unmap_region+0xb9/0x130
 [<ffffffff81161fc4>] ? kmem_cache_free+0x104/0x110
 [<ffffffff81141602>] ? detach_vmas_to_be_unmapped+0x92/0xe0
 [<ffffffff81142d05>] do_munmap+0x295/0x2f0
 [<ffffffff811443f3>] sys_munmap+0x53/0x80
 [<ffffffff81664502>] system_call_fastpath+0x16/0x1b