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Re: undiagnosed integer overflow in parsing frozen files


From: Eric Blake
Subject: Re: undiagnosed integer overflow in parsing frozen files
Date: Thu, 08 May 2008 13:43:35 -0600
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According to Jim Meyering on 5/8/2008 1:10 PM:
|
| However, given too long a string of digits, "Number" overflows.
| Considering the rigorous parsing elsewhere in that file, I think
| this must be accidental.

Accidental, but not unnoticed, and hopefully not severe.  I spotted the
same issue a couple of years ago when I first started patching m4, but as
I haven't spotted any security holes so far in using a truncated value, it
hasn't been my highest priority.  But now that you mention it, I'll
probably tighten up the check, and reject frozen files the moment an
integer overflows, rather than proceeding on indefinitely with the
truncated value (most likely to reject the file later when the rest of the
parse is out of sync).

- --
Don't work too hard, make some time for fun as well!

Eric Blake             address@hidden
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