diff --git a/drivers/mailbox/ti-msgmgr.c b/drivers/mailbox/ti-msgmgr.c
index 52136f99f54f..2079996092f5 100644
--- a/drivers/mailbox/ti-msgmgr.c
+++ b/drivers/mailbox/ti-msgmgr.c
@@ -20,6 +20,7 @@
 #include <linux/platform_device.h>
 #include <linux/property.h>
 #include <linux/soc/ti/ti-msgmgr.h>
+#include <linux/string.h>
 
 #define Q_DATA_OFFSET(proxy, queue, reg)	\
 		     ((0x10000 * (proxy)) + (0x80 * (queue)) + ((reg) * 4))
@@ -425,10 +426,15 @@ static int ti_msgmgr_send_data(struct mbox_chan *chan, void *data)
 
 	trail_bytes = message->len % sizeof(u32);
 	if (trail_bytes) {
-		u32 data_trail = *word_data;
+		/*
+		 * Copy only the trailing bytes instead of reading a full u32,
+		 * as the message buffer may end right after them and a u32
+		 * read would go past the end of it. This also leaves all
+		 * unused data as 0.
+		 */
+		u32 data_trail = 0;
 
-		/* Ensure all unused data is 0 */
-		data_trail &= 0xFFFFFFFF >> (8 * (sizeof(u32) - trail_bytes));
+		memcpy(&data_trail, word_data, trail_bytes);
 		writel(data_trail, data_reg);
 		data_reg += sizeof(u32);
 	}