+++ This bug was initially created as a clone of Bug #169260 +++ 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
(See followup from Linus; proposed patch won't be applied)
I have verified that RHEL 3 does not give access by default, both before and after X start (init 3). I have pam-0.75-58, initscripts-7.31.16.EL-1. When usbdevfs is mounted, no extra flags are supplied. Normally access is granted by giving options "devmode" or "devuid" to usbdevfs, but remember that one can do use chown(1) too. It is not persistent across reboots, but it works otherwise. Mark wrote that permissions are given, but perhaps he meant RHEL 4 and then cloned the bug into RHEL 3. I'm going to check if I have same userland as he did.
I am taking back the comment #3 for now. It is possible to open read-only, so the question is if harmful ioctls are available in such case.
The discusson on vendor-sec was also mirrored to lkml; here is the link to the most recent message (use thread previous to see the others) http://marc.theaimsgroup.com/?l=linux-kernel&m=112918286904030&w=2
This issue is on Red Hat Engineering's list of planned work items for the upcoming Red Hat Enterprise Linux 3.8 release. Engineering resources have been assigned and barring unforeseen circumstances, Red Hat intends to include this item in the 3.8 release.
Created attachment 127737 [details] Candidate #1 - Same as RHEL-4
A fix for this problem has just been committed to the RHEL3 U8 patch pool this evening (in kernel version 2.4.21-40.9.EL).
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-2006-0437.html