diff --git a/drivers/firmware/arm_ffa/driver.c b/drivers/firmware/arm_ffa/driver.c
index eb2782848283..b700b2e93e72 100644
--- a/drivers/firmware/arm_ffa/driver.c
+++ b/drivers/firmware/arm_ffa/driver.c
@@ -697,11 +697,10 @@ ffa_setup_and_transmit(u32 func_id, void *buffer, u32 max_fragsize,
 	for (idx = 0; idx < args->nattrs; idx++) {
 		ep_mem_access = buffer +
 			ffa_mem_desc_offset(buffer, idx, drv_info->version);
+		memset(ep_mem_access, 0, ffa_emad_size_get(drv_info->version));
 		ep_mem_access->receiver = args->attrs[idx].receiver;
 		ep_mem_access->attrs = args->attrs[idx].attrs;
 		ep_mem_access->composite_off = composite_offset;
-		ep_mem_access->flag = 0;
-		ep_mem_access->reserved = 0;
 		ffa_emad_impdef_value_init(drv_info->version,
 					   ep_mem_access->impdef_val,
 					   args->attrs[idx].impdef_val);
@@ -741,7 +740,7 @@ ffa_setup_and_transmit(u32 func_id, void *buffer, u32 max_fragsize,
 			constituents = buffer;
 		}
 
-		if ((void *)constituents - buffer > max_fragsize) {
+		if ((void *)constituents + sizeof(*constituents) - buffer > max_fragsize) {
 			pr_err("Memory Region Fragment > Tx Buffer size\n");
 			return -EFAULT;
 		}
@@ -750,7 +749,7 @@ ffa_setup_and_transmit(u32 func_id, void *buffer, u32 max_fragsize,
 		constituents->pg_cnt = args->sg->length / FFA_PAGE_SIZE;
 		constituents->reserved = 0;
 		constituents++;
-		frag_len += sizeof(struct ffa_mem_region_addr_range);
+		frag_len += sizeof(*constituents);
 	} while ((args->sg = sg_next(args->sg)));
 
 	return ffa_transmit_fragment(func_id, addr, buf_sz, frag_len,