On 08/13/2014 04:31 PM, Kevin Grittner wrote:
David Rowley <dgrowle...@gmail.com> wrote:

I had a quick look at the usages of strncpy in master tonight and
I've really just picked out the obviously broken ones for now.
The other ones, on first look, either look safe, or require some
more analysis to see what's actually done with the string.

Does anyone disagree with the 2 changes in the attached?

I am concerned that failure to check for truncation could allow
deletion of unexpected files or directories.  While this is
probably not as dangerous as *executing* unexpected files, it seems
potentially problematic.  At the very least, a code comment
explaining why calling unlink on something which is not what
appears to be expected is not a problem there.

Some might consider it overkill, but I tend to draw a pretty hard
line on deleting or executing random files, even if the odds seem
to be that the mangled name won't find a match.  Granted, those
problems exist now, but without checking for truncation it seems to
me that we're just deleting *different* incorrect filenames, not
really fixing the problem.

strlcpy is clearly better than strncpy here, but I wonder if we should have yet another string copying function that throws an error instead of truncating, if the buffer is too small. What you really want in these cases is a "path too long" error.

- Heikki

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