Out of bounds read error in wildcard_match.c

Hi,

I discovered an out of bounds read error in the file wildcard_match.c. Here's the code: /* find the end of each string */ while (*(++mask)); mask--; while (*(++data)); data--;

The problem with this: It will search for the end of the strings (zero-terminated), but it'll only start at position 1, not at position 0 (because the ++ in front of the variable will first increment and then return the value). However these strings can be empty.

This can be fixed by changing ++mask to mask++ (and same for data), then there must be a -=2 instead of -- afterwards. See attached patch.

I found this by compiling dovecot with address sanitizer and running the test suite.

cu,

Hanno Böck http://hboeck.de/

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