diff -up shadow-4.9/lib/attr.h.attr1 shadow-4.9/lib/attr.h
--- shadow-4.9/lib/attr.h.attr1	2026-05-15 10:12:37.710080392 +0200
+++ shadow-4.9/lib/attr.h	2026-05-15 10:12:37.710074405 +0200
@@ -0,0 +1,25 @@
+#ifndef SHADOW_INCLUDE_LIB_ATTR_H_
+#define SHADOW_INCLUDE_LIB_ATTR_H_
+
+
+#include "config.h"
+
+
+#if defined(__GNUC__)
+# define unused                      __attribute__((unused))
+# define NORETURN                    __attribute__((__noreturn__))
+# define format_attr(type, fmt, va)  __attribute__((format(type, fmt, va)))
+#else
+# define unused
+# define NORETURN
+# define format_attr(type, fmt, va)
+#endif
+
+#if (__GNUC__ >= 11) && !defined(__clang__)
+# define ATTR_MALLOC(deallocator)    [[gnu::malloc(deallocator)]]
+#else
+# define ATTR_MALLOC(deallocator)
+#endif
+
+
+#endif  // include guard
diff -up shadow-4.9/lib/Makefile.am.attr1 shadow-4.9/lib/Makefile.am
--- shadow-4.9/lib/Makefile.am.attr1	2021-07-22 23:55:35.000000000 +0200
+++ shadow-4.9/lib/Makefile.am	2026-05-15 10:13:33.477931504 +0200
@@ -11,6 +11,7 @@ libshadow_la_CPPFLAGS += -DVENDORDIR=\"$
 endif
 
 libshadow_la_SOURCES = \
+	attr.h \
 	commonio.c \
 	commonio.h \
 	defines.h \


From a61cf0068bf8b56dec5a1d42c9e9701199fcbb0f Mon Sep 17 00:00:00 2001
From: Alejandro Colomar <alx@kernel.org>
Date: Sun, 26 Nov 2023 18:38:40 +0100
Subject: [PATCH] lib/attr.h: Add ATTR_STRING() attribute macro

It signals that a function parameter is a string _before_ the call.

Suggested-by: Serge Hallyn <serge@hallyn.com>
Signed-off-by: Alejandro Colomar <alx@kernel.org>
---
 lib/attr.h | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/lib/attr.h b/lib/attr.h
index 56a2e0c9..b1f153c7 100644
--- a/lib/attr.h
+++ b/lib/attr.h
@@ -21,5 +21,11 @@
 # define ATTR_MALLOC(deallocator)
 #endif
 
+#if (__GNUC__ >= 14)
+# define ATTR_STRING(...)       [[gnu::null_terminated_string_arg(__VA_ARGS__)]]
+#else
+# define ATTR_STRING(...)
+#endif
+
 
 #endif  // include guard
-- 
2.54.0


diff -up shadow-4.9/lib/Makefile.am.subordinate-fix-duplicate-range shadow-4.9/lib/Makefile.am
--- shadow-4.9/lib/Makefile.am.subordinate-fix-duplicate-range	2021-07-22 23:55:35.000000000 +0200
+++ shadow-4.9/lib/Makefile.am	2026-05-15 09:57:53.269280378 +0200
@@ -61,6 +61,8 @@ libshadow_la_SOURCES = \
 	shadowio.h \
 	shadowmem.c \
 	spawn.c \
+	string/strcmp/streq.c \
+	string/strcmp/streq.h \
 	utent.c
 
 if WITH_TCB
diff -up shadow-4.9/lib/string/strcmp/streq.c.subordinate-fix-duplicate-range shadow-4.9/lib/string/strcmp/streq.c
--- shadow-4.9/lib/string/strcmp/streq.c.subordinate-fix-duplicate-range	2026-05-15 09:55:37.639772757 +0200
+++ shadow-4.9/lib/string/strcmp/streq.c	2026-05-15 09:55:37.639767504 +0200
@@ -0,0 +1,12 @@
+// SPDX-FileCopyrightText: 2024, Alejandro Colomar <alx@kernel.org>
+// SPDX-License-Identifier: BSD-3-Clause
+
+
+#include <config.h>
+
+#include <stdbool.h>
+
+#include "string/strcmp/streq.h"
+
+
+extern inline bool streq(const char *s1, const char *s2);
diff -up shadow-4.9/lib/string/strcmp/streq.h.subordinate-fix-duplicate-range shadow-4.9/lib/string/strcmp/streq.h
--- shadow-4.9/lib/string/strcmp/streq.h.subordinate-fix-duplicate-range	2026-05-15 09:55:37.639844826 +0200
+++ shadow-4.9/lib/string/strcmp/streq.h	2026-05-15 09:55:37.639821788 +0200
@@ -0,0 +1,30 @@
+// SPDX-FileCopyrightText: 2024, Alejandro Colomar <alx@kernel.org>
+// SPDX-License-Identifier: BSD-3-Clause
+
+
+#ifndef SHADOW_INCLUDE_LIB_STRING_STRCMP_STREQ_H_
+#define SHADOW_INCLUDE_LIB_STRING_STRCMP_STREQ_H_
+
+
+#include <config.h>
+
+#include <stdbool.h>
+#include <string.h>
+
+#include "attr.h"
+
+
+ATTR_STRING(1)
+ATTR_STRING(2)
+inline bool streq(const char *s1, const char *s2);
+
+
+/* Return true if s1 and s2 compare equal.  */
+inline bool
+streq(const char *s1, const char *s2)
+{
+	return strcmp(s1, s2) == 0;
+}
+
+
+#endif  // include guard
diff -up shadow-4.9/lib/subordinateio.c.subordinate-fix-duplicate-range shadow-4.9/lib/subordinateio.c
--- shadow-4.9/lib/subordinateio.c.subordinate-fix-duplicate-range	2026-05-15 09:55:37.628382347 +0200
+++ shadow-4.9/lib/subordinateio.c	2026-05-15 09:56:01.189509187 +0200
@@ -17,6 +17,8 @@
 #include <ctype.h>
 #include <fcntl.h>
 
+#include "string/strcmp/streq.h"
+
 #define ID_SIZE 31
 
 /*
@@ -839,18 +841,10 @@ int list_owner_ranges(const char *owner,
 	have_owner_id = get_owner_id(owner, id_type, id);
 
 	commonio_rewind(db);
-	while ((range = commonio_next(db)) != NULL) {
-		if (0 == strcmp(range->owner, owner)) {
-			if (!append_range(&ranges, range, count++)) {
-				free(ranges);
-				ranges = NULL;
-				count = -1;
-				goto out;
-			}
-		}
-
-		// Let's also compare with the ID
-		if (have_owner_id == true && 0 == strcmp(range->owner, id)) {
+	while (NULL != (range = commonio_next(db))) {
+		if (   streq(range->owner, owner)
+		    || (have_owner_id && streq(range->owner, id)))
+		{
 			if (!append_range(&ranges, range, count++)) {
 				free(ranges);
 				ranges = NULL;