On 1 Dec 2007 at 16:17, René Rhéaume wrote: > When I try to start a virtual machine VirtualBox 1.5.2 OSE and the > host kernel is ~hardened-sources-2.6.23, the virtual machine window > freezes and I find the following in dmesg :
so i've dug into the code a bit more and found out something. look at the following part of the register dump, in particular edi: > esi: 4bea5000 edi: 00084400 ebp: 00000000 esp: d5cf3ec4 00084400 = VM_IO | VM_RESERVED | VM_PFNMAP which in turn looks familiar to anyone who's seen the remap_pfn_range() function which sets these exact flags on the vma. now what happens is that virtualbox developers have apparently their own idea about how to do memory/vma allocation and population in the linux kernel and screw it up quite badly. i guess someone was a bit lazy and didn't want to implement a small filesystem to do it right but instead he opted for some really bad hacks and the new vma mirroring code in PaX detects it. while i could add a workaround (heck, you can remove the BUGs in pax_find_mirror_vma if you really want to), i won't do it as it's really a bug in virtualbox and they'd better fix it properly. on another note, i also tracked down why it failed here and it turns out they also have their own kernel module loader for god knows what reason, and that of course doesn't play well at all with KERNEXEC. -- [EMAIL PROTECTED] mailing list
