Branch: refs/heads/smoke-me/khw-17734
Home: https://github.com/Perl/perl5
Commit: 4d3640109bda059b8482fd71a043ac4586a10a50
https://github.com/Perl/perl5/commit/4d3640109bda059b8482fd71a043ac4586a10a50
Author: Karl Williamson <k...@cpan.org>
Date: 2020-04-29 (Wed, 29 Apr 2020)
Changed paths:
M regcomp.c
M t/re/pat_advanced.t
Log Message:
-----------
regcomp.c: Avoid use after free
It turns out that the SV returned by re_intuit_string() may be freed by
future calls to re_intuit_start(). Thus, the caller doesn't get clear
title to the returned SV. (This wasn't documented until the
commit immediately prior to this one.)
Cope with this situation by making a mortalized copy. This commit also
changes to use the copy's PV directly, simplifying some 'if' statements.
re_intuit_string() is effectively in the API, as it is an element in the
regex engine structure, callable by anyone. It should not be returning
a tenuous SV. That returned scalar should not freed before the pattern
it is for is freed. It is too late in the development cycle to change
this, so this workaround is presented instead for 5.32.
This fixes #17734.
