Fix a memory leak when compiling a regular expression

perl-5.33.7-regcomp.c-Remove-memory-leak.patch

@@ -0,0 +1,74 @@
+From 5f41fa466a67b5535aa8bcf4b814f242545ac7bd Mon Sep 17 00:00:00 2001
+From: Karl Williamson <khw@cpan.org>
+Date: Sat, 27 Feb 2021 11:43:41 -0700
+Subject: [PATCH] regcomp.c: Remove memory leak
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+This fixes GH #18604.  There was a path through the code where a
+particular SV did not get its reference count decremented.
+
+I did an audit of the function and came up with several other
+possiblities that are included in this commit.
+
+Further, there would be leaks for some instances of finding syntax
+errors in the input pattern, or when warnings are fatalized.  Those
+would require mortalizing some SVs, but that is beyond the scope of this
+commit.
+
+Signed-off-by: Petr Písař <ppisar@redhat.com>
+---
+ regcomp.c     | 7 +++++++
+ t/op/svleak.t | 3 ++-
+ 2 files changed, 9 insertions(+), 1 deletion(-)
+
+diff --git a/regcomp.c b/regcomp.c
+index e44c7a37e5..f5e5f581dc 100644
+--- a/regcomp.c
++++ b/regcomp.c
+@@ -18765,6 +18765,12 @@ S_regclass(pTHX_ RExC_state_t *pRExC_state, I32 *flagp, U32 depth,
+ 	RExC_end = save_end;
+ 	RExC_in_multi_char_class = 0;
+         SvREFCNT_dec_NN(multi_char_matches);
++        SvREFCNT_dec(properties);
++        SvREFCNT_dec(cp_list);
++        SvREFCNT_dec(simple_posixes);
++        SvREFCNT_dec(posixes);
++        SvREFCNT_dec(nposixes);
++        SvREFCNT_dec(cp_foldable_list);
+         return ret;
+     }
+ 
+@@ -20122,6 +20128,7 @@ S_regclass(pTHX_ RExC_state_t *pRExC_state, I32 *flagp, U32 depth,
+                                            RExC_parse - orig_parse);;
+     SvREFCNT_dec(cp_list);;
+     SvREFCNT_dec(only_utf8_locale_list);
++    SvREFCNT_dec(upper_latin1_only_utf8_matches);
+     return ret;
+ }
+ 
+diff --git a/t/op/svleak.t b/t/op/svleak.t
+index 6acc298c3d..3df4838be8 100644
+--- a/t/op/svleak.t
++++ b/t/op/svleak.t
+@@ -15,7 +15,7 @@ BEGIN {
+ 
+ use Config;
+ 
+-plan tests => 150;
++plan tests => 151;
+ 
+ # run some code N times. If the number of SVs at the end of loop N is
+ # greater than (N-1)*delta at the end of loop 1, we've got a leak
+@@ -278,6 +278,7 @@ eleak(2,0,'/[[:ascii:]]/');
+ eleak(2,0,'/[[.zog.]]/');
+ eleak(2,0,'/[.zog.]/');
+ eleak(2,0,'/|\W/', '/|\W/ [perl #123198]');
++eleak(2,0,'/a\sb/', '/a\sb/ [GH #18604]');
+ eleak(2,0,'no warnings; /(?[])/');
+ eleak(2,0,'no warnings; /(?[[a]+[b]])/');
+ eleak(2,0,'no warnings; /(?[[a]-[b]])/');
+-- 
+2.26.2
+

perl.spec

@@ -269,6 +269,10 @@ Patch54:        perl-5.33.6-t-run-locale.t-Rmv-LANGUAGE-from-environment.patch
 # in upstream after 5.33.6
 Patch55:        perl-5.32.1-hv.c-add-a-guard-clause-to-prevent-the-number-of-buc.patch
 
+# Fix a memory leak when compiling a regular expression, GH#18604,
+# in upstream after 5.33.7
+Patch56:        perl-5.33.7-regcomp.c-Remove-memory-leak.patch
+
 # Link XS modules to libperl.so with EU::CBuilder on Linux, bug #960048
 Patch200:       perl-5.16.3-Link-XS-modules-to-libperl.so-with-EU-CBuilder-on-Li.patch
 
@@ -4325,6 +4329,7 @@ you're not running VMS, this module does nothing.
 %patch53 -p1
 %patch54 -p1
 %patch55 -p1
+%patch56 -p1
 %patch200 -p1
 %patch201 -p1
 
@@ -4379,6 +4384,7 @@ perl -x patchlevel.h \
     'Fedora Patch53: Add missing entries to perldiag (GH#18276)' \
     'Fedora Patch54: Protect locale tests from LANGUAGE environment variable' \
     'Fedora Patch55: Prevent the number of buckets in a hash from getting too large' \
+    'Fedora Patch56: Fix a memory leak when compiling a regular expression (GH#18604)' \
     'Fedora Patch200: Link XS modules to libperl.so with EU::CBuilder on Linux' \
     'Fedora Patch201: Link XS modules to libperl.so with EU::MM on Linux' \
     %{nil}
@@ -7109,6 +7115,7 @@ popd
 * Thu Mar 04 2021 Petr Pisar <ppisar@redhat.com> - 4:5.32.1-472
 - Protect locale tests from LANGUAGE environment variable
 - Prevent the number of buckets in a hash from getting too large
+- Fix a memory leak when compiling a regular expression (GH#18604)
 
 * Tue Feb 09 2021 Petr Pisar <ppisar@redhat.com> - 4:5.32.1-471
 - Make accessing environment by DynaLoader thread-safe