[PATCH v4 7/8] test: fix format overflow in cryptodev test

[Stephen Hemminger]

The vdev args buffer could in theory get truncated if there were
lots of sockets or lcores. Handle that by checking return value
of snprintf.

Fixes: 8bfdd8a7f0f1 ("test/crypto: refactor to use sub test suites")

Signed-off-by: Stephen Hemminger <stephen at networkplumber.org>
---
 app/test/test_cryptodev.c | 22 ++++++++++++++++++----
 1 file changed, 18 insertions(+), 4 deletions(-)

diff --git a/app/test/test_cryptodev.c b/app/test/test_cryptodev.c
index 9bdd357727..bd6a2d3fa6 100644
--- a/app/test/test_cryptodev.c
+++ b/app/test/test_cryptodev.c
@@ -17713,8 +17713,16 @@ scheduler_testsuite_setup(void)
 		RTE_LCORE_FOREACH_WORKER(i) {
 			if (worker_core_count > 1)
 				break;
-			snprintf(vdev_args, sizeof(vdev_args),
-					"%s%d", temp_str, i);
+			ret = snprintf(vdev_args, sizeof(vdev_args),
+					   "%s%d", temp_str, i);
+
+			/* If too many args the result will have been truncated */
+			if (ret >= VDEV_ARGS_SIZE) {
+				RTE_LOG(ERR, USER1,
+					"Cryptodev scheduler test vdev arg size exceeded\n");
+				return TEST_FAILED;
+			}
+
 			strcpy(temp_str, vdev_args);
 			strlcat(temp_str, ";", sizeof(temp_str));
 			worker_core_count++;
@@ -17728,8 +17736,14 @@ scheduler_testsuite_setup(void)
 			return TEST_FAILED;
 		}
 		strcpy(temp_str, vdev_args);
-		snprintf(vdev_args, sizeof(vdev_args), "%s,socket_id=%d",
-				temp_str, socket_id);
+		ret = snprintf(vdev_args, sizeof(vdev_args), "%s,socket_id=%d",
+			       temp_str, socket_id);
+		if (ret >= VDEV_ARGS_SIZE) {
+			RTE_LOG(ERR, USER1,
+				"Cryptodev scheduler test vdev arg size exceeded\n");
+			return TEST_FAILED;
+		}
+
 		RTE_LOG(DEBUG, USER1, "vdev_args: %s\n", vdev_args);
 		nb_devs = rte_cryptodev_device_count_by_driver(
 				rte_cryptodev_driver_id_get(
-- 
2.51.0