diff --git a/alias.c b/alias.c
index 269892c356..4daafd9bda 100644
--- a/alias.c
+++ b/alias.c
@@ -21,9 +21,11 @@ static int config_alias_cb(const char *key, const char *value,
 		return 0;
 
 	if (data->alias) {
-		if (!strcasecmp(p, data->alias))
+		if (!strcasecmp(p, data->alias)) {
+			FREE_AND_NULL(data->v);
 			return git_config_string(&data->v,
 						 key, value);
+		}
 	} else if (data->list) {
 		string_list_append(data->list, p);
 	}
diff --git a/config.c b/config.c
index a025cfafe0..496cd1a61e 100644
--- a/config.c
+++ b/config.c
@@ -1414,8 +1414,10 @@ static int git_default_core_config(const char *var, const char *value,
 		return 0;
 	}
 
-	if (!strcmp(var, "core.attributesfile"))
+	if (!strcmp(var, "core.attributesfile")) {
+		FREE_AND_NULL(git_attributes_file);
 		return git_config_pathname(&git_attributes_file, var, value);
+	}
 
 	if (!strcmp(var, "core.hookspath")) {
 		if (ctx->kvi && ctx->kvi->scope == CONFIG_SCOPE_LOCAL &&
@@ -1428,6 +1430,7 @@ static int git_default_core_config(const char *var, const char *value,
 			      "again with "
 			      "`GIT_CLONE_PROTECTION_ACTIVE=false`"),
 			    value);
+		FREE_AND_NULL(git_hooks_path);
 		return git_config_pathname(&git_hooks_path, var, value);
 	}
 
@@ -1566,7 +1569,7 @@ static int git_default_core_config(const char *var, const char *value,
 
 	if (!strcmp(var, "core.checkroundtripencoding")) {
 		FREE_AND_NULL(check_roundtrip_encoding);
-		return git_config_string((const char **) &check_roundtrip_encoding, var, value);
+		return git_config_string(&check_roundtrip_encoding, var, value);
 	}
 
 	if (!strcmp(var, "core.notesref")) {
@@ -1576,8 +1579,10 @@ static int git_default_core_config(const char *var, const char *value,
 		return 0;
 	}
 
-	if (!strcmp(var, "core.editor"))
+	if (!strcmp(var, "core.editor")) {
+		FREE_AND_NULL(editor_program);
 		return git_config_string(&editor_program, var, value);
+	}
 
 	if (!strcmp(var, "core.commentchar") ||
 	    !strcmp(var, "core.commentstring")) {
@@ -1595,11 +1600,13 @@ static int git_default_core_config(const char *var, const char *value,
 		return 0;
 	}
 
-	if (!strcmp(var, "core.askpass"))
+	if (!strcmp(var, "core.askpass")) {
+		FREE_AND_NULL(askpass_program);
 		return git_config_string(&askpass_program, var, value);
+	}
 
 	if (!strcmp(var, "core.excludesfile")) {
-		free(excludes_file);
+		FREE_AND_NULL(excludes_file);
 		return git_config_pathname(&excludes_file, var, value);
 	}
 
@@ -1702,11 +1709,15 @@ static int git_default_sparse_config(const char *var, const char *value)
 
 static int git_default_i18n_config(const char *var, const char *value)
 {
-	if (!strcmp(var, "i18n.commitencoding"))
+	if (!strcmp(var, "i18n.commitencoding")) {
+		FREE_AND_NULL(git_commit_encoding);
 		return git_config_string(&git_commit_encoding, var, value);
+	}
 
-	if (!strcmp(var, "i18n.logoutputencoding"))
+	if (!strcmp(var, "i18n.logoutputencoding")) {
+		FREE_AND_NULL(git_log_output_encoding);
 		return git_config_string(&git_log_output_encoding, var, value);
+	}
 
 	/* Add other config variables here and to Documentation/config.txt. */
 	return 0;
@@ -1779,10 +1790,15 @@ static int git_default_push_config(const char *var, const char *value)
 
 static int git_default_mailmap_config(const char *var, const char *value)
 {
-	if (!strcmp(var, "mailmap.file"))
+	if (!strcmp(var, "mailmap.file")) {
+		FREE_AND_NULL(git_mailmap_file);
 		return git_config_pathname(&git_mailmap_file, var, value);
-	if (!strcmp(var, "mailmap.blob"))
+	}
+
+	if (!strcmp(var, "mailmap.blob")) {
+		FREE_AND_NULL(git_mailmap_blob);
 		return git_config_string(&git_mailmap_blob, var, value);
+	}
 
 	/* Add other config variables here and to Documentation/config.txt. */
 	return 0;
@@ -1790,8 +1806,10 @@ static int git_default_mailmap_config(const char *var, const char *value)
 
 static int git_default_attr_config(const char *var, const char *value)
 {
-	if (!strcmp(var, "attr.tree"))
+	if (!strcmp(var, "attr.tree")) {
+		FREE_AND_NULL(git_attr_tree);
 		return git_config_string(&git_attr_tree, var, value);
+	}
 
 	/*
 	 * Add other attribute related config variables here and to
diff --git a/t/t1306-xdg-files.sh b/t/t1306-xdg-files.sh
index 40d3c42618..53e5b290b9 100755
--- a/t/t1306-xdg-files.sh
+++ b/t/t1306-xdg-files.sh
@@ -7,6 +7,7 @@
 
 test_description='Compatibility with $XDG_CONFIG_HOME/git/ files'
 
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 test_expect_success 'read config: xdg file exists and ~/.gitconfig doesn'\''t' '
diff --git a/t/t1350-config-hooks-path.sh b/t/t1350-config-hooks-path.sh
index f6dc83e2aa..5c47f9ecc3 100755
--- a/t/t1350-config-hooks-path.sh
+++ b/t/t1350-config-hooks-path.sh
@@ -2,6 +2,7 @@
 
 test_description='Test the core.hooksPath configuration variable'
 
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 test_expect_success 'set up a pre-commit hook in core.hooksPath' '
diff --git a/t/t3415-rebase-autosquash.sh b/t/t3415-rebase-autosquash.sh
index fcc40d6fe1..22452ff84c 100755
--- a/t/t3415-rebase-autosquash.sh
+++ b/t/t3415-rebase-autosquash.sh
@@ -5,6 +5,7 @@ test_description='auto squash'
 GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main
 export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
 
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 . "$TEST_DIRECTORY"/lib-rebase.sh
diff --git a/t/t4041-diff-submodule-option.sh b/t/t4041-diff-submodule-option.sh
index 0c1502d4b0..8fc40e75eb 100755
--- a/t/t4041-diff-submodule-option.sh
+++ b/t/t4041-diff-submodule-option.sh
@@ -12,6 +12,7 @@ This test tries to verify the sanity of the --submodule option of git diff.
 GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main
 export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
 
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 # Tested non-UTF-8 encoding
diff --git a/t/t4060-diff-submodule-option-diff-format.sh b/t/t4060-diff-submodule-option-diff-format.sh
index 97c6424cd5..8ce67442d9 100755
--- a/t/t4060-diff-submodule-option-diff-format.sh
+++ b/t/t4060-diff-submodule-option-diff-format.sh
@@ -10,6 +10,7 @@ test_description='Support for diff format verbose submodule difference in git di
 This test tries to verify the sanity of --submodule=diff option of git diff.
 '
 
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 # Tested non-UTF-8 encoding
diff --git a/t/t4210-log-i18n.sh b/t/t4210-log-i18n.sh
index 75216f19ce..7120030b5c 100755
--- a/t/t4210-log-i18n.sh
+++ b/t/t4210-log-i18n.sh
@@ -1,6 +1,8 @@
 #!/bin/sh
 
 test_description='test log with i18n features'
+
+TEST_PASSES_SANITIZE_LEAK=true
 . ./lib-gettext.sh
 
 # two forms of é
diff --git a/t/t6006-rev-list-format.sh b/t/t6006-rev-list-format.sh
index 573eb97a0f..f1623b1c06 100755
--- a/t/t6006-rev-list-format.sh
+++ b/t/t6006-rev-list-format.sh
@@ -8,6 +8,7 @@ test_description='git rev-list --pretty=format test'
 GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main
 export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
 
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 . "$TEST_DIRECTORY"/lib-terminal.sh
 
diff --git a/t/t7005-editor.sh b/t/t7005-editor.sh
index 5fcf281dfb..b9822294fe 100755
--- a/t/t7005-editor.sh
+++ b/t/t7005-editor.sh
@@ -2,6 +2,7 @@
 
 test_description='GIT_EDITOR, core.editor, and stuff'
 
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 unset EDITOR VISUAL GIT_EDITOR
diff --git a/t/t7102-reset.sh b/t/t7102-reset.sh
index 62d9f846ce..2add26d768 100755
--- a/t/t7102-reset.sh
+++ b/t/t7102-reset.sh
@@ -10,6 +10,7 @@ Documented tests for git reset'
 GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main
 export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
 
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 commit_msg () {
diff --git a/t/t9129-git-svn-i18n-commitencoding.sh b/t/t9129-git-svn-i18n-commitencoding.sh
index 185248a4cd..01e1e8a8f7 100755
--- a/t/t9129-git-svn-i18n-commitencoding.sh
+++ b/t/t9129-git-svn-i18n-commitencoding.sh
@@ -4,7 +4,6 @@
 
 test_description='git svn honors i18n.commitEncoding in config'
 
-TEST_FAILS_SANITIZE_LEAK=true
 . ./lib-git-svn.sh
 
 compare_git_head_with () {
diff --git a/t/t9139-git-svn-non-utf8-commitencoding.sh b/t/t9139-git-svn-non-utf8-commitencoding.sh
index b7f756b2b7..22d80b0be2 100755
--- a/t/t9139-git-svn-non-utf8-commitencoding.sh
+++ b/t/t9139-git-svn-non-utf8-commitencoding.sh
@@ -4,7 +4,6 @@
 
 test_description='git svn refuses to dcommit non-UTF8 messages'
 
-TEST_FAILS_SANITIZE_LEAK=true
 . ./lib-git-svn.sh
 
 # ISO-2022-JP can pass for valid UTF-8, so skipping that in this test
