Hi, I was out for holiday last week and came back to my SL 7.1 desktop needing a slew of updates. I had been running VirtualBox-5.0-5.0.10_104061_el7-1.x86_64 against kernel-3.10.0-229.14.1.el7.x86_64 with out issue. After installing the latest kernel mentioned by Etienne, and attempting to rebuild the vboxdrv modules, I had similar failures. Afterward, I attempted to upgrade to VirtualBox-5.0-5.0.12_104815_el7-1.x86_64, I discovered the libdevmapper issue noted in the previous post which prevented the newer version from installing.
It seems that there is a VirtualBox bug filed against the EL7.2 3.10.0-327 kernel noted here: https://www.virtualbox.org/ticket/14866 which may be causing the issues you are encountering. Unfortunately, the testing build for EL7: https://www.virtualbox.org/download/testcase/VirtualBox-5.0-5.0.11_104721_el7-1.x86_64.rpm, does not install due to the same libdevmapper issue. I had hoped maybe the devmapper issue was introduced in builds between the latest testbuild and the release build for 5.0.12, no such luck. I have device-mapper-libs-1.02.93-3.el7_1.1.x86_64 installed, but it seems that the VirtualBox package is calling for device-mapper-libs-1.02.97, which doesn't seem to be available for SL7. The CentOS and Oracle Linux public yum repo's latest version is device-mapper-libs-1.02.107-5.el7.x86_64. Is that in the pipeline for release to SL7 soon? Thanks!