assertion botched

[chloe]

Configuration Information [Automatically generated, do not change]:
Machine: i486
OS: linux-gnu
Compiler: gcc
Compilation CFLAGS:  -DPROGRAM='bash' -DCONF_HOSTTYPE='i486' 
-DCONF_OSTYPE='linux-gnu' -DCONF_MACHTYPE='i486-pc-linux-gnu' 
-DCONF_VENDOR='pc' -DLOCALEDIR='/usr/share/locale' -DPACKAGE='bash' -DSHELL 
-DHAVE_CONFIG_H   -I.  -I../bash -I../bash/include -I../bash/lib   -g -O2 -Wall
uname output: Linux rama 2.6.32.14tigrerouge-dom0 #1 SMP Sun May 30 23:23:49 
CEST 2010 i686 GNU/Linux
Machine Type: i486-pc-linux-gnu

Bash Version: 3.2
Patch Level: 39
Release Status: release

Description:
        After running a script which waits for a long while, bash exits with 
the following message:
malloc: ../bash/dispose_cmd.c:241: assertion botched
free: underflow detected; mh_nbytes out of range
Aborting...Abandon

Repeat-By:
        Run the following piece of code (my code is a repetition of the 
following sequence)
for i in 
/var/www/boris/wordpress/wp-content/generated-factory/montan/Textures/*.png; do
# there we replace all textures with the one we want
FILENAME=$(basename $i)
mkdir -p "/var/www/boris/wordpress/wp-content/generated-factory/montan/Textures"
ln -sf 
"/var/www/boris/wordpress/wp-content/generated-factory/textures/000DEF.png" 
"/var/www/boris/wordpress/wp-content/generated-factory/montan/Textures/$FILENAME";
done
ln -sf 
"/var/www/boris/wordpress/wp-content/generated-factory/textures/000DEF.png" 
"/var/www/boris/wordpress/wp-content/generated-factory/montan/Textures/ModelTexture.png";
echo Triggering render;
mkdir -p 
"/var/www/boris/wordpress/wp-content/generated-factory/montan/CameraFront/neckborder";
chmod 777 
"/var/www/boris/wordpress/wp-content/generated-factory/montan/CameraFront/neckborder";
echo 'if not exist C:\3Dboris\montan\neckborder.max goto output' >  
"/var/www/boris/wordpress/wp-content/generated-factory/montan/action.bat"
echo 'C:' >> 
"/var/www/boris/wordpress/wp-content/generated-factory/montan/action.bat"
echo 'cd \3DBoris' >> 
"/var/www/boris/wordpress/wp-content/generated-factory/montan/action.bat"
echo 'copy /Y H:\montan\Textures\ModelTexture.png C:\3Dboris\Texture.png' >> 
"/var/www/boris/wordpress/wp-content/generated-factory/montan/action.bat"
echo 'C:\ImageMagick\montage.exe C:\3Dboris\Texture.png C:\3Dboris\Texture.png 
C:\3Dboris\Texture.png C:\3Dboris\Texture.png -mode Concatenate -tile 2x2 
C:\3Dboris\BiggerTexture.png' >> 
"/var/www/boris/wordpress/wp-content/generated-factory/montan/action.bat"
#echo 'C:\ImageMagick\montage.exe C:\3Dboris\BigTexture.png 
C:\3Dboris\BigTexture.png C:\3Dboris\BigTexture.png C:\3Dboris\BigTexture.png 
-mode Concatenate -tile 2x2 C:\3Dboris\BiggerTexture.png' >> 
"/var/www/boris/wordpress/wp-content/generated-factory/montan/action.bat"
echo 'for %%i In (C:\3Dboris\montan\Textures\*.png) DO copy /Y 
C:\3Dboris\BiggerTexture.png "%%i"' >> 
"/var/www/boris/wordpress/wp-content/generated-factory/montan/action.bat"
echo 'C:\Autodesk\3DS\3dsmaxcmd.exe C:\3Dboris\montan\neckborder.max 
-o=H:\montan\CameraFront\neckborder\000DEF.png -w 800 -h 600 
-camera:CameraFront' >> 
"/var/www/boris/wordpress/wp-content/generated-factory/montan/action.bat"
echo 'H:' >>  
"/var/www/boris/wordpress/wp-content/generated-factory/montan/action.bat"
echo 'cd H:\montan\CameraFront\neckborder' >>  
"/var/www/boris/wordpress/wp-content/generated-factory/montan/action.bat"
echo 'rename H:\montan\CameraFront\neckborder\000DEF0000.png 000DEF.png' >> 
"/var/www/boris/wordpress/wp-content/generated-factory/montan/action.bat";
echo ':output' >>  
"/var/www/boris/wordpress/wp-content/generated-factory/montan/action.bat"
echo 'echo "Got out"' >>  
"/var/www/boris/wordpress/wp-content/generated-factory/montan/action.bat"
unix2dos 
"/var/www/boris/wordpress/wp-content/generated-factory/montan/action.bat"
touch  "/var/www/boris/wordpress/wp-content/generated-factory/montan/LetsGo.txt"
chmod 777   
"/var/www/boris/wordpress/wp-content/generated-factory/montan/LetsGo.txt";
echo Triggered render montan CameraFront 000DEF.png;
while [ ! -f 
/var/www/boris/wordpress/wp-content/generated-factory/montan/LetsGo.txt ]; do 
echo -n '.' ; sleep 1; done;
while [ -f 
/var/www/boris/wordpress/wp-content/generated-factory/montan/LetsGo.txt ] ; do 
sleep 1; echo -n '.'; done; # rendering

with file 
/var/www/boris/wordpress/wp-content/generated-factory/montan/LetsGo.txt 
existing.

After a long while (I let it run overnight so that counts for several thousands 
seconds) it will die with the message i quoted.

FWIW this script is not run by a regular user but by www-data.