[PATCH v1 2/2] test: env: add test for himport_r SIZE_MAX overflow guard

[Aristo Chen]

Add a unit test that verifies himport_r rejects SIZE_MAX as the size
argument, ensuring the integer overflow guard added to lib/hashtable.c
is exercised and not accidentally regressed.

Signed-off-by: Aristo Chen <aristo.chen at canonical.com>
---
 test/env/hashtable.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/test/env/hashtable.c b/test/env/hashtable.c
index 16e49358888..ce9689f46d7 100644
--- a/test/env/hashtable.c
+++ b/test/env/hashtable.c
@@ -122,3 +122,20 @@ static int env_test_htab_deletes(struct unit_test_state *uts)
 	return 0;
 }
 ENV_TEST(env_test_htab_deletes, 0);
+
+/* Verify himport_r rejects SIZE_MAX to prevent integer overflow in malloc */
+static int env_test_htab_import_overflow(struct unit_test_state *uts)
+{
+	struct hsearch_data htab;
+
+	memset(&htab, 0, sizeof(htab));
+	ut_asserteq(1, hcreate_r(SIZE, &htab));
+
+	/* SIZE_MAX would cause malloc(size + 1) to wrap to malloc(0) */
+	ut_asserteq(0, himport_r(&htab, "", SIZE_MAX, '\0', 0, 0, 0, NULL));
+
+	hdestroy_r(&htab);
+	return 0;
+}
+
+ENV_TEST(env_test_htab_import_overflow, 0);
-- 
2.43.0