Harald Welte mailed the lkml on 20050925 with a report of how to cause a local oops if a user has permissions to access an arbitrary usb device. I've rated this as 'moderate' instead of 'important' due to that requirement. Although usb permissions will be given automatically to console users, a DOS from a user who has physical access to a machine is little extra risk and we ignore that from the severity calculation. See the following URL for the description and patch http://marc.theaimsgroup.com/?l=linux-kernel&m=112766129313883
Created attachment 120010 [details] Candidate #1 - Linus' patch adapted to RHEL 4
Regarding my proposal of checking if we still belong to the same process group (or equivalent), it probably is not worth pursuing. Even if I were able to work out kinks, it does not offer any decisive advantages over Linus' idea of checking UID/EUID (as implemented by Harald).
committed in stream U4 build 34.11. A test kernel with this patch is available from http://people.redhat.com/~jbaron/rhel4/
This issue is on Red Hat Engineering's list of planned work items for the upcoming Red Hat Enterprise Linux 4.4 release. Engineering resources have been assigned and barring unforeseen circumstances, Red Hat intends to include this item in the 4.4 release.
An advisory has been issued which should help the problem described in this bug report. This report is therefore being closed with a resolution of ERRATA. For more information on the solution and/or where to find the updated files, please follow the link below. You may reopen this bug report if the solution does not work for you. http://rhn.redhat.com/errata/RHSA-2006-0575.html