NetPBM, multiple vulnerabilities

[Alan Cox <alan () lxorguk ukuu org uk>]

NetPBM contains large numbers of maths overflow errors, some of which
are deeply theoretical as they involve passing 2Gb file names, others
of which are straight forward x * y * depth type overflows, of the
kind which have shown up in numerous other imaging libraries. Finally
there are a couple of signed value overflows which appear safe but
since signed maths overflow is not defined for C may not be.

An initial set of patches were sent to vendors and to the NetPBM
maintainers. Today Martin Schulze found two minor errors in the changes
released so far. These don't appear to leave open holes, just cause
correctness problems.

While netpbm is not setuid it is used by some applications for print
formatting and also for converting untrusted images received from third
parties. Although the patches appear to address the main problems as
patch author I believe the right path is probably to recognize that
netpbm is very old code, written in times with a different threat model
and use something else instead.

Al Viro found the original bug. Alan Cox did the initial fixes. 
Martin Schulze and Sebastian Kramer provided additional fixes to the
patches. www.MachinaeSupremacy.com provided the music to keep me sane
through the initial tedious process.

The patches are over 100K so please ask your vendor or check the
main netpbm site.

Alan
--
'On the other hand, you sometimes wish the world, like nethack, had some
        sort of "Genocide All Stupid People" key sequence.' 
                        - Alec Muffett