diff --git a/SOURCES/GSSAPI-0.28-Fix-a-crash-in-gss_release_oid-when-destructing-out_.patch b/SOURCES/GSSAPI-0.28-Fix-a-crash-in-gss_release_oid-when-destructing-out_.patch
new file mode 100644
index 0000000..a85b332
--- /dev/null
+++ b/SOURCES/GSSAPI-0.28-Fix-a-crash-in-gss_release_oid-when-destructing-out_.patch
@@ -0,0 +1,79 @@
+From 159042c71bbdd5909f792208dcdffffb1674ecfe Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Petr=20P=C3=ADsa=C5=99?= <ppisar@redhat.com>
+Date: Thu, 19 Aug 2021 16:07:06 +0200
+Subject: [PATCH] Fix a crash in gss_release_oid() when destructing out_mech
+ returned by gss_accept_sec_context()
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+If Perl GSSAPI was built against MIT krb5, an example gss-server.pl
+script crashed like this:
+
+ Program terminated with signal SIGSEGV, Segmentation fault.
+ #0 0x00007f27f3d48b23 in __GI___libc_free (mem=<optimized out>)
+ at malloc.c:3131
+ 3131 ar_ptr = arena_for_chunk (p);
+ (gdb) bt
+ #0 0x00007f27f3d48b23 in __GI___libc_free (mem=<optimized out>)
+ at malloc.c:3131
+ #1 0x00007f27f2fe17c6 in generic_gss_release_oid (
+ minor_status=minor_status@entry=0x7fffc750333c,
+ oid=oid@entry=0x7fffc7503340) at oid_ops.c:102
+ #2 0x00007f27f2fee6df in gss_release_oid (
+ minor_status=minor_status@entry=0x7fffc750333c,
+ oid=oid@entry=0x7fffc7503340) at g_initialize.c:202
+ #3 0x00007f27f322f5cf in XS_GSSAPI__OID_DESTROY (my_perl=<optimized out>,
+ cv=0x564037c87130) at ./xs/OID.xs:24
+ #4 0x00007f27f4f58149 in Perl_pp_entersub (my_perl=0x5640378d42a0)
+ at pp_hot.c:4227
+
+The cause is that gss_accept_sec_context() returns a pointer to
+a static storage in out_mech argument. When GSSAPI passed out_mech to
+a desctructor, the invoked gss_release_oid() crashed when freeing the
+memory.
+
+Accoding to RFC 2744, the static storage is correct. Hence the flaw is
+on Perl GSSAPI side. This patch fixes it by copying the out_mech OID
+object on a heap which is then correctly processed by
+gss_release_oid().
+
+CPAN RT#121873.
+
+Signed-off-by: Petr Písař <ppisar@redhat.com>
+---
+ xs/Context.xs | 18 ++++++++++++++++++
+ 1 file changed, 18 insertions(+)
+
+diff --git a/xs/Context.xs b/xs/Context.xs
+index d176f08..4549595 100644
+--- a/xs/Context.xs
++++ b/xs/Context.xs
+@@ -80,6 +80,24 @@ accept(context, acc_cred, in_token, binding, out_name, out_mech, out_token, out_
+ &in_token, binding, out_name, out_mech,
+ &out_token, out_flags, out_time,
+ delegated_cred);
++#if !defined(HEIMDAL)
++ if (out_mech && *out_mech) {
++ /* RFC 2744 documents that the returned *out_mech is a pointer
++ * to static data. To prevent from freeing them when destructing
++ * out_mech, we change *out_mech into a pointer to a heap-allocated
++ * buffer with the same content. Otherwise, MITKRB5-provided
++ * gss_release_oid() deallocator which cannot recognize this static
++ * storage would crash. We use malloc() because gss_release_oid() used
++ * free(). */
++ GSSAPI__OID copy = malloc(sizeof(*copy));
++ if (!copy) croak("Not enough memory for copying out_mech!");
++ copy->elements = malloc((*out_mech)->length);
++ if (!copy->elements) croak("Not enough memory for copying out_mech!");
++ memcpy(copy->elements, (*out_mech)->elements, (*out_mech)->length);
++ copy->length = (*out_mech)->length;
++ *out_mech = copy;
++ }
++#endif
+ OUTPUT:
+ RETVAL
+ context
+--
+2.31.1
+
diff --git a/SPECS/perl-GSSAPI.spec b/SPECS/perl-GSSAPI.spec
index 1df19ae..8b74525 100644
--- a/SPECS/perl-GSSAPI.spec
+++ b/SPECS/perl-GSSAPI.spec
@@ -6,12 +6,14 @@
Name: perl-GSSAPI
Version: 0.28
-Release: 23%{?dist}
+Release: 25%{?dist}
Summary: Perl extension providing access to the GSSAPIv2 library
License: GPL+ or Artistic
Group: Development/Libraries
URL: http://search.cpan.org/dist/GSSAPI/
Source0: http://www.cpan.org/authors/id/A/AG/AGROLMS/GSSAPI-%{version}.tar.gz
+# Fix a crash in gss_release_oid() when destructing out_mech (rhbz #1937764, CPAN RT#121873)
+Patch0: GSSAPI-0.28-Fix-a-crash-in-gss_release_oid-when-destructing-out_.patch
BuildRequires: findutils
BuildRequires: gcc
BuildRequires: krb5-devel
@@ -37,6 +39,7 @@ distribution from MIT.
%prep
%setup -q -n GSSAPI-%{version}
+%patch0 -p1
chmod -c a-x examples/*.pl
%build
@@ -59,6 +62,12 @@ find %{buildroot} -type f -name '*.bs' -empty -delete
%{_mandir}/man3/*
%changelog
+* Thu Aug 19 2021 Jitka Plesnikova <jplesnik@redhat.com> - 0.28-25
+- Resolves: rhbz#1937764 - Fix a crash in gss_release_oid() when destructing out_mech
+
+* Mon Aug 16 2021 Jitka Plesnikova <jplesnik@redhat.com> - 0.28-24
+- Resolves: rhbz#1937764 - Fix comparison of OID structure
+
* Mon Feb 19 2018 Jitka Plesnikova <jplesnik@redhat.com> - 0.28-23
- Add build-require gcc