With -next-20130204+ in ubuntu 12.10 VM (so the 80x25 VGA device/console): [ 0.666410] udevd[97]: starting version 175 [ 0.674043] udevd[97]: udevd:[97]: segfault at ffffffffff5fd020 ip 00007fff069e277f sp 00007fff068c9ef8 error d and boots to an initramfs prompt. git bisect (log attached) blames: commit 7b5c4a65cc27f017c170b025f8d6d75dabb11c6f Merge: 3596f5b 949db15 Author: H. Peter Anvin Date: Fri Jan 25 16:31:21 2013 -0800 Merge tag 'v3.8-rc5' into x86/mm The __pa() fixup series that follows touches KVM code that is not present in the existing branch based on v3.7-rc5, so merge in the current upstream from Linus. Signed-off-by: H. Peter Anvin This only happens with the VGA device/console but that is the default configuration for Ubuntu/KVM because it blacklists pretty much every fb driver. I can confirm this _does not_ happen with same config on mainline 3.8-rc7. Just confirmed that the same fault occurs with next-20130211. Regards, Peter Hurley