Bug 84129

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User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.3a) Gecko/20021207
Phoenix/0.5

Description of problem:
If I run "TERM=xterm mc" in minicom (mc is GNU Midnight Commander 4.6.0)
minicom crashes when mc exits.

Version-Release number of selected component (if applicable):


How reproducible:
Always

Steps to Reproduce:
1. Run minicom
2. Login to a remote system, make sure is has mc-4.6.0 installed.
3. Run "TERM=xterm mc"
4. Consequtively Press Escape 0 Enter.


Actual Results:  minicom crashes

Expected Results:  the command prompt reappears in the minicom window

Additional info:

I haven't tried to reduce this to a minimal case, because the reason of the
crash is pretty clear from debugging.

When minicom starts, vt_trans is initialized, but savetrans is not (it
contains zeroes because it's static).  Then some escape sequence comes and
vt_trans is restored from savetrans (although it was never saved there). Using
vt_trans after that causes access to memory just above NULL.

There are two fixes - initialize savetrans with the same values as
vt_trans or check if vt_trans[charset] is NULL.  This patch has both, but only
one part is required.

I don't think this bug can be exploited to expose data or execute
commands.  However, it is possible to use it for a denial of service
attack if the attacker can affect the text displayed to other users at
startup (not likely).

I contacted the maintainer (Jukka Lahtinen <walker>) and the mailing
list minicom-devel.com.br.  The e-mail to the maintainer
bounced. There was no reply from the mailing list.