lib: rpmsg: replace strncpy with internal safe_strcpy

The strncpy function does not ensure that the destination string is
null-terminated. To address this issue, replace strncpy with the
internal safe_strcpy() function, which guarantees null-termination of the
destination string but also access only in buffer memory ranges.

Note: (void)safe_strcpy(...) indicates that the return value is
intentionally ignored.

Signed-off-by: Arnaud Pouliquen <[email protected]>

lib/rpmsg/rpmsg.c

@@ -7,6 +7,7 @@
  * SPDX-License-Identifier: BSD-3-Clause
  */
 
+#include <internal/string.h>
 #include <openamp/rpmsg.h>
 #include <metal/alloc.h>
 
@@ -141,7 +142,7 @@ int rpmsg_send_ns_message(struct rpmsg_endpoint *ept, unsigned long flags)
 
 	ns_msg.flags = flags;
 	ns_msg.addr = ept->addr;
-	strncpy(ns_msg.name, ept->name, sizeof(ns_msg.name));
+	(void)safe_strcpy(ns_msg.name, sizeof(ns_msg.name), ept->name, strlen(ept->name));
 	ret = rpmsg_send_offchannel_raw(ept, ept->addr,
 					RPMSG_NS_EPT_ADDR,
 					&ns_msg, sizeof(ns_msg), true);
@@ -305,7 +306,11 @@ void rpmsg_register_endpoint(struct rpmsg_device *rdev,
 			     rpmsg_ept_cb cb,
 			     rpmsg_ns_unbind_cb ns_unbind_cb, void *priv)
 {
-	strncpy(ept->name, name ? name : "", sizeof(ept->name));
+	if (name)
+		(void)safe_strcpy(ept->name, sizeof(ept->name), name, sizeof(name));
+	else
+		ept->name[0] = 0;
+
 	ept->refcnt = 1;
 	ept->addr = src;
 	ept->dest_addr = dest;