[backport]rtld: copy terminating null in tunables_strdup (bug 28256)

Signed-off-by: Lv Ying <lvying6@huawei.com>
(cherry picked from commit ff7eb18d6c589301f4c58dc8ef176901e97eed70)

backport-rtld-copy-terminating-null-in-tunables_strdup-bug-28.patch

@@ -0,0 +1,28 @@
+From ef8e2a0633bb701a89dd4967e1a87dc33bb7032c Mon Sep 17 00:00:00 2001
+From: Andreas Schwab <schwab@linux-m68k.org>
+Date: Mon, 23 Aug 2021 10:19:52 +0200
+Subject: [PATCH] rtld: copy terminating null in tunables_strdup (bug 28256)
+
+Avoid triggering a false positive from valgrind by copying the terminating
+null in tunables_strdup.  At this point the heap is still clean, but
+valgrind is stricter here.
+---
+ elf/dl-tunables.c | 2 --
+ 1 file changed, 2 deletions(-)
+
+diff --git a/elf/dl-tunables.c b/elf/dl-tunables.c
+index 4c9d36e39807..2494a4826af2 100644
+--- a/elf/dl-tunables.c
++++ b/elf/dl-tunables.c
+@@ -52,8 +52,6 @@ tunables_strdup (const char *in)
+   if (out == (void *)-1)
+     return NULL;
+ 
+-  i--;
+-
+   while (i-- > 0)
+     out[i] = in[i];
+ 
+-- 
+2.18.4
+

glibc.spec

@@ -59,7 +59,7 @@
 ##############################################################################
 Name: 	 	glibc
 Version: 	2.28
-Release: 	77
+Release: 	78
 Summary: 	The GNU libc libraries
 License:	%{all_license}
 URL: 		http://www.gnu.org/software/glibc/
@@ -136,6 +136,7 @@ Patch52: backport-_dl_exception_create_format-Add-missing-va_end.patch
 Patch53: backport-CVE-2021-38604-0001-librt-add-test-bug-28213.patch
 Patch54: backport-CVE-2021-38604-0002-librt-fix-null-pointer-deference.patch
 Patch55: backport-ldconfig-avoid-leak-on-empty-paths-in-config-file.patch
+Patch56: backport-rtld-copy-terminating-null-in-tunables_strdup-bug-28.patch
 
 Provides: ldconfig rtld(GNU_HASH) bundled(gnulib)
 
@@ -1160,6 +1161,10 @@ fi
 %doc hesiod/README.hesiod
 
 %changelog
+* Wed Sep 29 2021 Lv Ying<lvying6@huawei.com> - 2.28-78
+- ldconfig: avoid leak on empty paths in config file
+  https://sourceware.org/git/?p=glibc.git;a=commit;h=a4f5a3103fc3e7974dbe35b411cba9f670807cde
+
 * Tue Aug 31 2021 Lv Ying<lvying6@huawei.com> - 2.28-77
 - ldconfig: avoid leak on empty paths in config file
   https://sourceware.org/git/?p=glibc.git;a=commit;h=b0234d79e7d82475d1666f25326ec045c045b3ed