Red Hat Bugzilla – Bug 91585
ioperm security fix is flawed, still uses uninitialized memory
Last modified: 2007-04-18 12:53:59 EDT
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Description of problem:
The 2.4.20-13.9 backport of the ioperm security fix only copies 1/4th of the
bitmap when it should be copying the whole thing. This still leaves memory
uninitialized, so the original hole is still not completely fixed. Furthermore,
some programs that previously worked (svgalib and FCE Ultra in particular) are
See below for links to both a test case and a fix.
Version-Release number of selected component (if applicable):
Steps to Reproduce:
There is a test case in this mailing list post (but ignore the comments about
2.5 also being broken -- it's not, and I corrected myself in a followup):
Actual Results: Test case often segfaults when performing inb operation.
(FWIW, FCE Ultra (emulator for Nintendo), when invoked as "fceu", typically
Expected Results: Test case should always print "result: " and some number,
when run as root.
(And "fceu" should print command line option help without segfaulting first.)
A possible fix is here:
(If that's too invasive and you want me to make a simpler patch, feel free to
let me know.)
As you might be able to tell from the URLs above, I already posted about this on
the linux-kernel mailing list (regarding 2.4.21-rc3). I'm filing this report in
Bugzilla because it happens with Red Hat's own kernels too.
FWIW, my patch is now in 2.4.21-rc4.
An errata 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.