Red Hat Bugzilla – Bug 197673
CVE-2006-2935 Possible buffer overflow in DVD handling
Last modified: 2007-11-30 17:06:55 EST
Reported by Marcus Meissner to the Kernel Bugzilla:
The dvd_read_bca() function in drivers/cdrom/cdrom.c shows a potential buffer
The variable buf[4+188] is allocated on the stack, however cgc.cmd and
cgc.buflen are set to 255:
cgc.cmd = cgc.buflen = 0xff;
This can be exploited by a custom made USB Storage device and used for local
privilege escalation (aka plug-in this USB device to get root).
This function has been introduced in 2.2.16 (back in 2000) and as of today it
hasn't changed. Jens Axboe confirmed that this is a typo and it should read:
cgc.cmd = cgc.buflen & 0xff;
It is to mask high bits of the length. It doesn't use the high 8 bits for
transfer length, since we are always < 256 for this case.
there doesn't appear to be any practical way to reproduce this. I've verified
the patch is being applied to the e.71 kernel from the file
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.