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    SubjectRe: 2.5.28 and partitions
    Mike Touloumtzis writes:
    > On Thu, Aug 01, 2002 at 05:24:37PM -0400, Albert D. Cahalan wrote:

    >> There's just that little overflow problem to worry about,
    > Ummm:
    > -- stuff ASCII digits into u64 (or u32, or whatever)
    > -- if (still more digits)
    > -- printk("partition too big to mount!\n")
    > -- return error
    > How hard is that?

    I refer to overflowing the space allowed for your
    partition table. Programs will generate the data,
    then write it out. If the data gets too long, then
    you overwrite part of your first filesystem.
    Alternately, the partition table gets truncated
    at the maximum size -- with or without a '\0'.

    But sure, overflowing a u64 is also a problem.
    This will not be checked for. Either the u64 will
    get overflowed, or the parser will take what fits
    and then mis-interpret the remaining digits as
    a second number.

    >> trailing garbage,
    > Don't write garbage into your partition table.

    I can see multiple ways for this to happen.
    Take the length of the new data, with or without
    the trailing '\0', and write it out. Write the
    whole partition table, including uninitialized
    data that happens to be in memory. (some other
    program will of course not ignore trailing garbage)

    >> encouragement of assumptions about the maximum size...
    >> is that a %d or a %llu or what?
    > See above. Use leading '-' for negative numbers. ASCII has no
    > 2's complement ambiguity issues.

    You've got to stuff it into something eventually,
    unless you want to implement ASCII math. Will you
    be using plain C, or C++ operator overloading?

    Yeah, just what we need. The /proc mess expanding
    into partition tables. That sounds like a great way
    to increase filesystem destruction performance.

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