Unbound Segmentation Fault w/ log_info Functions From Python Mod

[drachs]

log_info is a C function that takes printf style variadic arguments as a parameter. SWIG by default does not wrap variadic arguments. It always calls log_info as:

log_info(param1, NULL)

This means that all string parameters have to be cooked down into param1. This is the python way of doing things, so it itself is not a problem. However '%' is a special character in printf, and cannot be sent safely in the first parameter. Therefore, no user data is safe to use with this logger by default.

For purpose of example, the following line will segmentation fault unbound when called from operate:

log_info("CRASH %s CRASH" % ("%40n"))

I think log_info and related functions exposed to python should be replaced with a stub that calls

log_info("%s", input)

We worked around this problem with the following python code:

def log(value):
    unbound_log_info(value.replace("%", "%%"))

unbound_log_info = log_info
log_info = log
log_err = log
log_warn = log

[wcawijngaards]

Thanks for the report! Fixed it by providing one string argument log functions, like you suggested. Also for verbose(level, string), log_err, and log_warn, aside from log_info. The original functions are still available as unbound_log_info, unbound_log_err and so on.