[PATCH] libio: Fix gconv-related memory leak [BZ #24583]

[Florian Weimer <fweimer at redhat dot com>]

__gconv_close_transform performs locking internally, so remove
the locking operations.

2019-05-20  Florian Weimer  <fweimer@redhat.com>

	* libio/iofclose.c (_IO_new_fclose): Call __gconv_close_transform
	instead of __gconv_release_step.
	* libio/Makefile (tests): Add tst-wfile-gconv.
	(tst-wfile-gconv-ENV): Enable mtrace.
	(generated): Add tst-wfile-gconv.mtrace, tst-wfile-gconv.check.
	(tests-special): Add tst-wfile-gconv-mem.out.
	(tst-wfile-gconv.out): Depend on locales.
	(tst-wfile-gconv-mem.out): Add mtrace rule.
	* libio/tst-wfile-gconv.c: New file.

diff --git a/libio/Makefile b/libio/Makefile
index a5236c7042..641f4f00af 100644
--- a/libio/Makefile
+++ b/libio/Makefile
@@ -66,7 +66,7 @@ tests = tst_swprintf tst_wprintf tst_swscanf tst_wscanf tst_getwc tst_putwc   \
 	tst-fwrite-error tst-ftell-partial-wide tst-ftell-active-handler \
 	tst-ftell-append tst-fputws tst-bz22415 tst-fgetc-after-eof \
 	tst-sprintf-ub tst-sprintf-chk-ub tst-bz24051 tst-bz24153 \
-	tst-wfile-sync
+	tst-wfile-sync tst-wfile-gconv
 
 tests-internal = tst-vtables tst-vtables-interposed tst-readline
 
@@ -163,10 +163,12 @@ tst_wprintf2-ARGS = "Some Text"
 test-fmemopen-ENV = MALLOC_TRACE=$(objpfx)test-fmemopen.mtrace
 tst-fopenloc-ENV = MALLOC_TRACE=$(objpfx)tst-fopenloc.mtrace
 tst-bz22415-ENV = MALLOC_TRACE=$(objpfx)tst-bz22415.mtrace
+tst-wfile-gconv-ENV = MALLOC_TRACE=$(objpfx)tst-wfile-gconv.mtrace
 
 generated += test-fmemopen.mtrace test-fmemopen.check
 generated += tst-fopenloc.mtrace tst-fopenloc.check
 generated += tst-bz22415.mtrace tst-bz22415.check
+generated += tst-wfile-gconv.mtrace tst-wfile-gconv.check
 
 aux	:= fileops genops stdfiles stdio strops
 
@@ -181,7 +183,7 @@ shared-only-routines = oldiofopen oldiofdopen oldiofclose oldfileops	\
 
 ifeq ($(run-built-tests),yes)
 tests-special += $(objpfx)test-freopen.out $(objpfx)test-fmemopen-mem.out \
-		 $(objpfx)tst-bz22415-mem.out
+		 $(objpfx)tst-bz22415-mem.out $(objpfx)tst-wfile-gconv-mem.out
 ifeq (yes,$(build-shared))
 # Run tst-fopenloc-cmp.out and tst-openloc-mem.out only if shared
 # library is enabled since they depend on tst-fopenloc.out.
@@ -214,6 +216,7 @@ $(objpfx)tst-ungetwc2.out: $(gen-locales)
 $(objpfx)tst-widetext.out: $(gen-locales)
 $(objpfx)tst_wprintf2.out: $(gen-locales)
 $(objpfx)tst-wfile-sync.out: $(gen-locales)
+$(objpfx)tst-wfile-gconv.out: $(gen-locales)
 endif
 
 $(objpfx)test-freopen.out: test-freopen.sh $(objpfx)test-freopen
@@ -237,3 +240,7 @@ $(objpfx)tst-fopenloc-mem.out: $(objpfx)tst-fopenloc.out
 $(objpfx)tst-bz22415-mem.out: $(objpfx)tst-bz22415.out
 	$(common-objpfx)malloc/mtrace $(objpfx)tst-bz22415.mtrace > $@; \
 	$(evaluate-test)
+
+$(objpfx)tst-wfile-gconv-mem.out: $(objpfx)tst-wfile-gconv.out
+	$(common-objpfx)malloc/mtrace $(objpfx)tst-wfile-gconv.mtrace > $@; \
+	$(evaluate-test)
diff --git a/libio/iofclose.c b/libio/iofclose.c
index 8a80dd0b78..f4c7299db3 100644
--- a/libio/iofclose.c
+++ b/libio/iofclose.c
@@ -61,10 +61,10 @@ _IO_new_fclose (FILE *fp)
 	 the conversion functions.  */
       struct _IO_codecvt *cc = fp->_codecvt;
 
-      __libc_lock_lock (__gconv_lock);
-      __gconv_release_step (cc->__cd_in.__cd.__steps);
-      __gconv_release_step (cc->__cd_out.__cd.__steps);
-      __libc_lock_unlock (__gconv_lock);
+      __gconv_close_transform (cc->__cd_in.__cd.__steps,
+			       cc->__cd_in.__cd.__nsteps);
+      __gconv_close_transform (cc->__cd_out.__cd.__steps,
+			       cc->__cd_out.__cd.__nsteps);
     }
   else
     {
diff --git a/libio/tst-wfile-gconv.c b/libio/tst-wfile-gconv.c
new file mode 100644
index 0000000000..de603b32d2
--- /dev/null
+++ b/libio/tst-wfile-gconv.c
@@ -0,0 +1,36 @@
+/* Test that non-built-in gconv modules do not cause memory leak (bug 24583).
+   Copyright (C) 2019 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <locale.h>
+#include <mcheck.h>
+#include <support/check.h>
+#include <support/xstdio.h>
+
+static int
+do_test (void)
+{
+  mtrace ();
+
+  TEST_VERIFY_EXIT (setlocale (LC_ALL, "ja_JP.EUC-JP") != NULL);
+  xfclose (xfopen ("/etc/passwd", "r,ccs=UTF-8"));
+  xfclose (xfopen ("/etc/passwd", "r"));
+
+  return 0;
+}
+
+#include <support/test-driver.c>