Fix: TNEF dump hanging

[ylecuyer]

Hello, while running clamav in debug mode, we found a file that was hanging the process.

After investigation, it turns out it is an eml with a winmail.data attachment > 8kb

So, in order to dump, it loops over the file with BUFSIZ chunks using fmap_readn

fmap_readn can return either -1 or 0 (

clamav/libclamav/fmap.h

Line 301 in 86a3835

return 0;

) but in the dump code only the -1 case is handled

It is hard to add a test, we can't share the original file and I found no way to create a similar file

[val-ms]

Thanks for the fix! As we confirmed in direct message conversation, this issue only affects running in debug mode (i.e. clamscan's --debug or clamd's Debug yes options).

With the latest update, your fix looks good to me. Thanks again!