diff --git a/scripts/run-regression-tests b/scripts/run-regression-tests
index 97fb9f6a0..1de609dc2 100755
--- a/scripts/run-regression-tests
+++ b/scripts/run-regression-tests
@@ -713,7 +713,7 @@ do
   # v4.13) and commit 6f303d60534c ("gcc-9: silence 'address-of-packed-member'
   # warning"; v5.1).
   for w in -Wno-format-truncation -Wno-format-overflow -Wno-int-in-bool-context -Wno-address-of-packed-member; do
-      if gcc -c -xc - "$w" </dev/null >&/dev/null; then
+      if gcc -c -xc -E - "$w" </dev/null >&/dev/null; then
 	  KCFLAGS+=" $w"
       fi
   done
diff --git a/scst/include/scst.h b/scst/include/scst.h
index a3453f0e9..5da726d7d 100644
--- a/scst/include/scst.h
+++ b/scst/include/scst.h
@@ -4846,6 +4846,7 @@ static inline struct scatterlist *__sg_next_inline(struct scatterlist *sg)
 	return sg;
 }
 
+/* Inline version of sg_next() from lib/scatterlist.c in the Linux kernel. */
 static inline struct scatterlist *sg_next_inline(struct scatterlist *sg)
 {
 	if (sg_is_last(sg))
@@ -5019,9 +5020,6 @@ static inline void scst_put_sg_buf(struct scst_cmd *cmd, void *buf,
  * negative error code otherwise.
  *
  * "Page" argument returns the starting page, "offset" - offset in it.
- *
- * The "put" function "puts" the buffer. It should be always be used, because
- * in future may need to do some additional operations.
  */
 static inline int __scst_get_sg_page(struct scst_cmd *cmd, int sg_cnt,
 	struct page **page, int *offset)
diff --git a/scst/src/scst_lib.c b/scst/src/scst_lib.c
index d9378c4a4..7c4e858bd 100644
--- a/scst/src/scst_lib.c
+++ b/scst/src/scst_lib.c
@@ -6846,7 +6846,7 @@ static void scst_cwr_read_cmd_finished(struct scst_cmd *cmd)
 	 * It must not happen, because get_cdb_info_compare_and_write()
 	 * supposed to ensure that.
 	 */
-	EXTRACHECKS_BUG_ON(rc != 0);
+	WARN_ONCE(rc != 0, "scst_adjust_sg_get_tail() failed: %d\n", rc);
 
 	wcmd->tgt_i_data_buf_alloced = 1;
 
@@ -6870,13 +6870,27 @@ out_finish:
 	goto out;
 }
 
+/*
+ * The Data-Out Buffer contains two instances of logical block data:
+ * 1) the compare instance, in which:
+ *   A) the user data is used for the compare operation; and
+ *   B) the protection information, if any, is not used;
+ * and
+ * 2) the write instance, in which:
+ *   A) the user data is used for the write operations; and
+ *   B) the protection information, if any, is used for the write operations.
+ *
+ * Note: cmd->data_len is half of the DataOut buffer size while cmd->bufflen
+ * and cmd->expected_transfer_len refer to the entire DataOut buffer.
+ */
 enum scst_exec_res scst_cmp_wr_local(struct scst_cmd *cmd)
 {
 	enum scst_exec_res res = SCST_EXEC_COMPLETED;
 	struct scst_cwr_priv *cwrp;
 	uint8_t read16_cdb[16];
 	struct scst_cmd *rcmd;
-	int data_len;
+	const int data_len = cmd->data_len;
+	const uint32_t num_lbas = data_len >> cmd->dev->block_shift;
 
 	TRACE_ENTRY();
 
@@ -6912,7 +6926,13 @@ enum scst_exec_res scst_cmp_wr_local(struct scst_cmd *cmd)
 	cwrp->cwr_orig_cmd = cmd;
 	cwrp->cwr_finish_fn = scst_cwr_read_cmd_finished;
 
-	data_len = cmd->data_len;
+	if (cmd->bufflen != scst_cmd_get_expected_transfer_len_data(cmd)) {
+		PRINT_ERROR("COMPARE AND WRITE: data buffer length mismatch (CDB %u <> ini %u)",
+			    cmd->bufflen,
+			    scst_cmd_get_expected_transfer_len_data(cmd));
+		scst_set_invalid_field_in_cdb(cmd, 13/*NLB*/, 0);
+		goto out_done;
+	}
 
 	/*
 	 * As required by SBC, DIF PI, if any, is not checked for the read part
@@ -6922,7 +6942,7 @@ enum scst_exec_res scst_cmp_wr_local(struct scst_cmd *cmd)
 	read16_cdb[0] = READ_16;
 	read16_cdb[1] = cmd->cdb[1] & ~0xE0; /* as required, see above */
 	put_unaligned_be64(cmd->lba, &read16_cdb[2]);
-	put_unaligned_be32(data_len >> cmd->dev->block_shift, &read16_cdb[10]);
+	put_unaligned_be32(num_lbas, &read16_cdb[10]);
 
 	rcmd = scst_create_prepare_internal_cmd(cmd, read16_cdb,
 		sizeof(read16_cdb), SCST_CMD_QUEUE_HEAD_OF_QUEUE);