flat_xor_hd: better validate args

Previously, we'd segfault with args like k=1, m=3, hd=3.

Change-Id: I8a1d92f388c54fe4f5b357eaf85a27e6b334df11

2 files changed, 24 insertions, 1 deletions

diff --git a/src/builtin/xor_codes/xor_hd_code.c b/src/builtin/xor_codes/xor_hd_code.c
index 5c4d052..9e41ad1 100644
--- a/src/builtin/xor_codes/xor_hd_code.c
+++ b/src/builtin/xor_codes/xor_hd_code.c
@@ -664,7 +664,7 @@ xor_code_t* init_xor_hd_code(int k, int m, int hd)
       if (k <= 10 && k >= 5) {
         is_valid = 1;
       }
-    } else if (m == 3) {
+    } else if (m == 3 && k == 3) {
       is_valid = 1;
     }
   }
diff --git a/test/liberasurecode_test.c b/test/liberasurecode_test.c
index f009a2d..b296c9d 100644
--- a/test/liberasurecode_test.c
+++ b/test/liberasurecode_test.c
@@ -1538,6 +1538,28 @@ static void test_jerasure_rs_cauchy_init_failure()
     assert(-EBACKENDINITERR == desc);
 }
 
+static void test_flat_xor_hd3_init_failure()
+{
+    struct ec_args bad_args[] = {
+        {.k = 1, .m = 5, .hd=3},
+        {.k = 5, .m = 1, .hd=3},
+        {.k = 4, .m = 4, .hd=3},
+        {.k = 1, .m = 3, .hd=3},
+        {.k = 4, .m = 3, .hd=3},
+    };
+
+    for (int i = 0; i < sizeof(bad_args)/sizeof(bad_args[0]); ++i) {
+        int desc = -1;
+        desc = liberasurecode_instance_create(
+            EC_BACKEND_FLAT_XOR_HD, &bad_args[i]);
+        if (-EBACKENDNOTAVAIL == desc) {
+            fprintf (stderr, "Backend library not available!\n");
+            return;
+        }
+        assert(-EBACKENDINITERR == desc);
+    }
+}
+
 static void test_simple_encode_decode(const ec_backend_id_t be_id,
                                      struct ec_args *args)
 {
@@ -1821,6 +1843,7 @@ struct testcase testcases[] = {
     TEST(test_decode_with_missing_multi_parity, EC_BACKEND_NULL, CHKSUM_NONE),
     // Flat XOR backend tests
     TEST_SUITE(EC_BACKEND_FLAT_XOR_HD),
+    TEST(test_flat_xor_hd3_init_failure, EC_BACKENDS_MAX, 0),
     // Jerasure RS Vand backend tests
     TEST_SUITE(EC_BACKEND_JERASURE_RS_VAND),
     TEST(test_jerasure_rs_vand_simple_encode_decode_over32, EC_BACKENDS_MAX, 0),