Bug in stats module causing endless write to file

Dear maintainers of connman,

I would like to report a bug in the statistics module of connman that is caused when the definition of time_t changes from 32-bit to 64-bit, e.g., after a Yocto update from dunfell to scarthgap.

On systems that experience a high number of wifi reconnects this sometimes leads to an infinite loop when connman rotates its statistics, causing high cpu-load in the connman process and creating an ever increasing temporary file in /var/lib/connman/.

The bug can be traced to src/stats.c, where stats_record, the record type containing time_t, is written to /var/lib/connman/<profile>/data. The data file contains a header and a ring-buffer type structure with elements of type stats_record. When the data file is full, connman removes old entries by first writing them to a temporary file in /var/lib/connman/. During the rotation of the statistics in the process_file function, the abort criterium for the while loop processing the entries is effectively iter->it == iter->end, which may in some cases never become true if an existing data file contains records of mixed type.

As a workaround, I would suggest disabling the stats module with --disable-stats. A possible fix could involve saving the size of stats_record in the header on creation and invalidating an opened file on a discrepancy.

Best,
Peter