diff --git a/examples/iscsiclient.c b/examples/iscsiclient.c
index 2aadf0b..95dbe87 100644
--- a/examples/iscsiclient.c
+++ b/examples/iscsiclient.c
@@ -561,12 +561,12 @@ void discovery_cb(struct iscsi_context *iscsi, int status, void *command_data, v
 
 	printf("discovery callback   status:%04x\n", status);
 
-	if (status != 0) {
+	if (status != 0 || command_data == NULL) {
 		printf("Failed to do discovery on target. : %s\n", iscsi_get_error(iscsi));
 		exit(10);
 	}
 
-	for(addr=command_data; addr; addr=addr->next) {	
+	for(addr = command_data; addr; addr = addr->next) {	
 		printf("Target:%s Address:%s\n", addr->target_name, addr->portals->portal);
 	}
 
diff --git a/test-tool/iscsi-multipath.c b/test-tool/iscsi-multipath.c
index 3fec560..70e38db 100644
--- a/test-tool/iscsi-multipath.c
+++ b/test-tool/iscsi-multipath.c
@@ -149,7 +149,7 @@ mpath_check_matching_ids_devid_vpd(int num_sds,
 			SCSI_INQUIRY_PAGECODE_DEVICE_IDENTIFICATION,
 			64,
 			EXPECT_STATUS_GOOD);
-		if (inq_task && inq_task->status != SCSI_STATUS_GOOD) {
+		if (inq_task == NULL || inq_task->status != SCSI_STATUS_GOOD) {
 			printf("Inquiry command failed : %s\n",
 			       sds[i]->error_str);
 			goto err_cleanup;
@@ -273,7 +273,7 @@ mpath_check_matching_ids_serial_vpd(int num_sds,
 		inquiry(sds[i], &inq_task, 1,
 			SCSI_INQUIRY_PAGECODE_UNIT_SERIAL_NUMBER, 64,
 			EXPECT_STATUS_GOOD);
-		if (inq_task && inq_task->status != SCSI_STATUS_GOOD) {
+		if (inq_task == NULL || inq_task->status != SCSI_STATUS_GOOD) {
 			printf("Inquiry command failed : %s\n",
 			       sds[i]->error_str);
 			goto err_cleanup;
diff --git a/test-tool/iscsi-support.c b/test-tool/iscsi-support.c
index 4c83d44..3006461 100644
--- a/test-tool/iscsi-support.c
+++ b/test-tool/iscsi-support.c
@@ -337,7 +337,6 @@ static struct scsi_task *send_scsi_command(struct scsi_device *sdev, struct scsi
 		/* Where to store the sense_data, if there was an error */
 		io_hdr.sbp = sense;
 		io_hdr.mx_sb_len = sense_len;
-		sense_len=0;
 
 		/* Transfer direction, either in or out. Linux does not yet
 		   support bidirectional SCSI transfers ?
@@ -386,7 +385,6 @@ static struct scsi_task *send_scsi_command(struct scsi_device *sdev, struct scsi
 		if(io_hdr.sb_len_wr > 0){
 			task->status = SCSI_STATUS_CHECK_CONDITION;
 			scsi_parse_sense_data(&task->sense, sense);
-			sense_len=io_hdr.sb_len_wr;
 			snprintf(buf, sizeof(buf), "SENSE KEY:%s(%d) ASCQ:%s(0x%04x)",
 				 scsi_sense_key_str(task->sense.key),
 				 task->sense.key,
diff --git a/test-tool/test_get_lba_status_unmap_single.c b/test-tool/test_get_lba_status_unmap_single.c
index fd8b9ac..4ae9088 100644
--- a/test-tool/test_get_lba_status_unmap_single.c
+++ b/test-tool/test_get_lba_status_unmap_single.c
@@ -29,7 +29,6 @@
 void
 test_get_lba_status_unmap_single(void)
 {
-	int ret;
 	uint64_t i;
 	struct unmap_list list[1];
 	struct scsi_task *t = NULL;
@@ -50,19 +49,17 @@ test_get_lba_status_unmap_single(void)
 
 	logging(LOG_VERBOSE, "Write the first %i blocks with a known "
 		"pattern and thus map the blocks", 256 + lbppb);
-	ret = write10(sd, 0, (256 + lbppb) * block_size,
-		      block_size, 0, 0, 0, 0, 0, scratch,
-		      EXPECT_STATUS_GOOD);
-	CU_ASSERT_EQUAL(ret, 0);
+	WRITE10(sd, 0, (256 + lbppb) * block_size,
+                block_size, 0, 0, 0, 0, 0, scratch,
+                EXPECT_STATUS_GOOD);
 
 	for (i = 0; i + lbppb <= 256; i += lbppb) {
 		logging(LOG_VERBOSE, "Unmap a single physical block at LBA:%"
 			PRIu64 " (number of logical blocks: %d)", i, lbppb);
 		list[0].lba = i;
 		list[0].num = lbppb;
-		ret = unmap(sd, 0, list, 1,
-			    EXPECT_STATUS_GOOD);
-		CU_ASSERT_EQUAL(ret, 0);
+		UNMAP(sd, 0, list, 1,
+                      EXPECT_STATUS_GOOD);
 
 		logging(LOG_VERBOSE, "Read the status of the block at LBA:%"
 			PRIu64, i);
@@ -105,16 +102,15 @@ test_get_lba_status_unmap_single(void)
 	for (i = lbppb; i + lbppb <= 256; i += lbppb) {
 		logging(LOG_VERBOSE, "Write the first %i blocks with a known "
 			"pattern and thus map the blocks", (256 + lbppb));
-		ret = write10(sd, 0, (256 + lbppb) * block_size,
-			      block_size, 0, 0, 0, 0, 0, scratch,
-			      EXPECT_STATUS_GOOD);
+		WRITE10(sd, 0, (256 + lbppb) * block_size,
+                        block_size, 0, 0, 0, 0, 0, scratch,
+                        EXPECT_STATUS_GOOD);
 
 		logging(LOG_VERBOSE, "Unmap %" PRIu64 " blocks at LBA 0", i);
 		list[0].lba = 0;
 		list[0].num = i;
-		ret = unmap(sd, 0, list, 1,
-			    EXPECT_STATUS_GOOD);
-		CU_ASSERT_EQUAL(ret, 0);
+		UNMAP(sd, 0, list, 1,
+                      EXPECT_STATUS_GOOD);
 
 		logging(LOG_VERBOSE, "Read the status of the block at LBA:0");
 
diff --git a/test-tool/test_sanitize_block_erase.c b/test-tool/test_sanitize_block_erase.c
index 15b73dc..0b1d289 100644
--- a/test-tool/test_sanitize_block_erase.c
+++ b/test-tool/test_sanitize_block_erase.c
@@ -37,6 +37,9 @@ check_wabereq(void)
 	READ10(sd, &task_ret, 0, block_size, block_size, 0, 0, 0, 0, 0, NULL,
 	       EXPECT_STATUS_GOOD);
 	CU_ASSERT_PTR_NOT_NULL_FATAL(task_ret);
+        if (task_ret == NULL) {
+                return;
+        }
 	CU_ASSERT_NOT_EQUAL(task_ret->status, SCSI_STATUS_CANCELLED);
 
 	switch (inq_bdc->wabereq) {
diff --git a/test-tool/test_sanitize_crypto_erase.c b/test-tool/test_sanitize_crypto_erase.c
index de0de98..1c96e48 100644
--- a/test-tool/test_sanitize_crypto_erase.c
+++ b/test-tool/test_sanitize_crypto_erase.c
@@ -37,6 +37,9 @@ check_wacereq(void)
 	READ10(sd, &task_ret, 0, block_size, block_size, 0, 0, 0, 0, 0, NULL,
 	       EXPECT_STATUS_GOOD);
 	CU_ASSERT_PTR_NOT_NULL_FATAL(task_ret);
+        if (task_ret == NULL) {
+                return;
+        }
 	CU_ASSERT_NOT_EQUAL(task_ret->status, SCSI_STATUS_CANCELLED);
 
 	switch (inq_bdc->wabereq) {