diff --git a/libs/libc/libc.h b/libs/libc/libc.h
index 7a81e44549c..897e1f7df35 100644
--- a/libs/libc/libc.h
+++ b/libs/libc/libc.h
@@ -83,7 +83,8 @@ FAR char *__dtoa(double d, int mode, int ndigits, FAR int *decpt,
 
 /* Defined in lib_getfullpath.c */
 
-int lib_getfullpath(int dirfd, FAR const char *path, FAR char *fullpath);
+int lib_getfullpath(int dirfd, FAR const char *path,
+                    FAR char *fullpath, size_t fulllen);
 
 /* Defined in lib_fopen.c */
 
diff --git a/libs/libc/misc/lib_fchmodat.c b/libs/libc/misc/lib_fchmodat.c
index 7ebb47c966e..c2a96817fb3 100644
--- a/libs/libc/misc/lib_fchmodat.c
+++ b/libs/libc/misc/lib_fchmodat.c
@@ -67,7 +67,7 @@ int fchmodat(int dirfd, FAR const char *path, mode_t mode, int flags)
   char fullpath[PATH_MAX];
   int ret;
 
-  ret = lib_getfullpath(dirfd, path, fullpath);
+  ret = lib_getfullpath(dirfd, path, fullpath, sizeof(fullpath));
   if (ret < 0)
     {
       set_errno(-ret);
diff --git a/libs/libc/misc/lib_fstatat.c b/libs/libc/misc/lib_fstatat.c
index af64110f3d1..99003aa4bb8 100644
--- a/libs/libc/misc/lib_fstatat.c
+++ b/libs/libc/misc/lib_fstatat.c
@@ -68,7 +68,7 @@ int fstatat(int dirfd, FAR const char *path, FAR struct stat *buf,
   char fullpath[PATH_MAX];
   int ret;
 
-  ret = lib_getfullpath(dirfd, path, fullpath);
+  ret = lib_getfullpath(dirfd, path, fullpath, sizeof(fullpath));
   if (ret < 0)
     {
       set_errno(-ret);
diff --git a/libs/libc/misc/lib_getfullpath.c b/libs/libc/misc/lib_getfullpath.c
index 1cd454c38e6..7e457c71a8e 100644
--- a/libs/libc/misc/lib_getfullpath.c
+++ b/libs/libc/misc/lib_getfullpath.c
@@ -42,7 +42,8 @@
  *
  ****************************************************************************/
 
-int lib_getfullpath(int dirfd, FAR const char *path, FAR char *fullpath)
+int lib_getfullpath(int dirfd, FAR const char *path,
+                    FAR char *fullpath, size_t fulllen)
 {
   if (path == NULL || fullpath == NULL)
     {
@@ -52,7 +53,7 @@ int lib_getfullpath(int dirfd, FAR const char *path, FAR char *fullpath)
     {
       /* The path is absolute, then dirfd is ignored. */
 
-      strlcpy(fullpath, path, PATH_MAX);
+      strlcpy(fullpath, path, fulllen);
       return 0;
     }
 
@@ -73,7 +74,7 @@ int lib_getfullpath(int dirfd, FAR const char *path, FAR char *fullpath)
         }
 #endif
 
-      sprintf(fullpath, "%s/%s", pwd, path);
+      snprintf(fullpath, fulllen, "%s/%s", pwd, path);
       return 0;
     }
   else
@@ -85,7 +86,7 @@ int lib_getfullpath(int dirfd, FAR const char *path, FAR char *fullpath)
       ret = fcntl(dirfd, F_GETPATH, fullpath);
       if (ret >= 0)
         {
-          strlcat(fullpath, path, PATH_MAX);
+          strlcat(fullpath, path, fulllen);
         }
 
       return 0;
diff --git a/libs/libc/misc/lib_mkdirat.c b/libs/libc/misc/lib_mkdirat.c
index 9932f900eed..db99dbdb661 100644
--- a/libs/libc/misc/lib_mkdirat.c
+++ b/libs/libc/misc/lib_mkdirat.c
@@ -65,7 +65,7 @@ int mkdirat(int dirfd, FAR const char *path, mode_t mode)
   char fullpath[PATH_MAX];
   int ret;
 
-  ret = lib_getfullpath(dirfd, path, fullpath);
+  ret = lib_getfullpath(dirfd, path, fullpath, sizeof(fullpath));
   if (ret < 0)
     {
       set_errno(-ret);
diff --git a/libs/libc/misc/lib_mkfifo.c b/libs/libc/misc/lib_mkfifo.c
index 5999fb39f40..bbe3551ef08 100644
--- a/libs/libc/misc/lib_mkfifo.c
+++ b/libs/libc/misc/lib_mkfifo.c
@@ -115,7 +115,7 @@ int mkfifoat(int dirfd, FAR const char *path, mode_t mode)
   char fullpath[PATH_MAX];
   int ret;
 
-  ret = lib_getfullpath(dirfd, path, fullpath);
+  ret = lib_getfullpath(dirfd, path, fullpath, sizeof(fullpath));
   if (ret < 0)
     {
       set_errno(-ret);
diff --git a/libs/libc/misc/lib_mknod.c b/libs/libc/misc/lib_mknod.c
index 205300a91b5..c4a3bb859fa 100644
--- a/libs/libc/misc/lib_mknod.c
+++ b/libs/libc/misc/lib_mknod.c
@@ -135,7 +135,7 @@ int mknodat(int dirfd, FAR const char *path, mode_t mode, dev_t dev)
   char fullpath[PATH_MAX];
   int ret;
 
-  ret = lib_getfullpath(dirfd, path, fullpath);
+  ret = lib_getfullpath(dirfd, path, fullpath, sizeof(fullpath));
   if (ret < 0)
     {
       set_errno(-ret);
diff --git a/libs/libc/misc/lib_openat.c b/libs/libc/misc/lib_openat.c
index 20be9bb916f..9ce18d73503 100644
--- a/libs/libc/misc/lib_openat.c
+++ b/libs/libc/misc/lib_openat.c
@@ -67,7 +67,7 @@ int openat(int dirfd, FAR const char *path, int oflags, ...)
   mode_t mode = 0;
   int ret;
 
-  ret = lib_getfullpath(dirfd, path, fullpath);
+  ret = lib_getfullpath(dirfd, path, fullpath, sizeof(fullpath));
   if (ret < 0)
     {
       set_errno(-ret);
diff --git a/libs/libc/misc/lib_utimensat.c b/libs/libc/misc/lib_utimensat.c
index 2fed37d87fe..989bd8ea944 100644
--- a/libs/libc/misc/lib_utimensat.c
+++ b/libs/libc/misc/lib_utimensat.c
@@ -67,7 +67,7 @@ int utimensat(int dirfd, FAR const char *path,
   char fullpath[PATH_MAX];
   int ret;
 
-  ret = lib_getfullpath(dirfd, path, fullpath);
+  ret = lib_getfullpath(dirfd, path, fullpath, sizeof(fullpath));
   if (ret < 0)
     {
       set_errno(-ret);
diff --git a/libs/libc/stdio/lib_renameat.c b/libs/libc/stdio/lib_renameat.c
index 12bd24cd41a..99abe268a6c 100644
--- a/libs/libc/stdio/lib_renameat.c
+++ b/libs/libc/stdio/lib_renameat.c
@@ -72,10 +72,12 @@ int renameat(int olddirfd, FAR const char *oldpath,
   char newfullpath[PATH_MAX];
   int ret;
 
-  ret = lib_getfullpath(olddirfd, oldpath, oldfullpath);
+  ret = lib_getfullpath(olddirfd, oldpath,
+                        oldfullpath, sizeof(oldfullpath));
   if (ret >= 0)
     {
-      ret = lib_getfullpath(newdirfd, newpath, newfullpath);
+      ret = lib_getfullpath(newdirfd, newpath,
+                            newfullpath, sizeof(newfullpath));
     }
 
   if (ret < 0)
diff --git a/libs/libc/unistd/lib_access.c b/libs/libc/unistd/lib_access.c
index da35dbc9928..d35abcdcacc 100644
--- a/libs/libc/unistd/lib_access.c
+++ b/libs/libc/unistd/lib_access.c
@@ -138,7 +138,7 @@ int faccessat(int dirfd, FAR const char *path, int amode, int flags)
   char fullpath[PATH_MAX];
   int ret;
 
-  ret = lib_getfullpath(dirfd, path, fullpath);
+  ret = lib_getfullpath(dirfd, path, fullpath, sizeof(fullpath));
   if (ret < 0)
     {
       set_errno(-ret);
diff --git a/libs/libc/unistd/lib_fchownat.c b/libs/libc/unistd/lib_fchownat.c
index db3b26c91ac..a140c669deb 100644
--- a/libs/libc/unistd/lib_fchownat.c
+++ b/libs/libc/unistd/lib_fchownat.c
@@ -69,7 +69,7 @@ int fchownat(int dirfd, FAR const char *path, uid_t owner,
   char fullpath[PATH_MAX];
   int ret;
 
-  ret = lib_getfullpath(dirfd, path, fullpath);
+  ret = lib_getfullpath(dirfd, path, fullpath, sizeof(fullpath));
   if (ret < 0)
     {
       set_errno(-ret);
diff --git a/libs/libc/unistd/lib_linkat.c b/libs/libc/unistd/lib_linkat.c
index 4c2a8530ccb..f0b252095f6 100644
--- a/libs/libc/unistd/lib_linkat.c
+++ b/libs/libc/unistd/lib_linkat.c
@@ -80,10 +80,12 @@ int linkat(int olddirfd, FAR const char *path1,
   char newfullpath[PATH_MAX];
   int ret;
 
-  ret = lib_getfullpath(olddirfd, path1, oldfullpath);
+  ret = lib_getfullpath(olddirfd, path1,
+                        oldfullpath, sizeof(oldfullpath));
   if (ret >= 0)
     {
-      ret = lib_getfullpath(newdirfd, path2, newfullpath);
+      ret = lib_getfullpath(newdirfd, path2,
+                            newfullpath, sizeof(newfullpath));
     }
 
   if (ret < 0)
diff --git a/libs/libc/unistd/lib_readlinkat.c b/libs/libc/unistd/lib_readlinkat.c
index fe911dd6195..85e863b9aa1 100644
--- a/libs/libc/unistd/lib_readlinkat.c
+++ b/libs/libc/unistd/lib_readlinkat.c
@@ -71,7 +71,7 @@ ssize_t readlinkat(int dirfd, FAR const char *path, FAR char *buf,
   char fullpath[PATH_MAX];
   int ret;
 
-  ret = lib_getfullpath(dirfd, path, fullpath);
+  ret = lib_getfullpath(dirfd, path, fullpath, sizeof(fullpath));
   if (ret < 0)
     {
       set_errno(-ret);
diff --git a/libs/libc/unistd/lib_symlinkat.c b/libs/libc/unistd/lib_symlinkat.c
index 33d6698eed0..6a6d6ee9c10 100644
--- a/libs/libc/unistd/lib_symlinkat.c
+++ b/libs/libc/unistd/lib_symlinkat.c
@@ -68,7 +68,7 @@ int symlinkat(FAR const char *path1, int dirfd, FAR const char *path2)
   char fullpath[PATH_MAX];
   int ret;
 
-  ret = lib_getfullpath(dirfd, path2, fullpath);
+  ret = lib_getfullpath(dirfd, path2, fullpath, sizeof(fullpath));
   if (ret < 0)
     {
       set_errno(-ret);
diff --git a/libs/libc/unistd/lib_unlinkat.c b/libs/libc/unistd/lib_unlinkat.c
index 4ceb3c8950f..cde938743bd 100644
--- a/libs/libc/unistd/lib_unlinkat.c
+++ b/libs/libc/unistd/lib_unlinkat.c
@@ -69,7 +69,7 @@ int unlinkat(int dirfd, FAR const char *path, int flags)
   char fullpath[PATH_MAX];
   int ret;
 
-  ret = lib_getfullpath(dirfd, path, fullpath);
+  ret = lib_getfullpath(dirfd, path, fullpath, sizeof(fullpath));
   if (ret < 0)
     {
       set_errno(-ret);
diff --git a/libs/libc/unistd/lib_utimes.c b/libs/libc/unistd/lib_utimes.c
index d115aec7c51..16e29451178 100644
--- a/libs/libc/unistd/lib_utimes.c
+++ b/libs/libc/unistd/lib_utimes.c
@@ -54,7 +54,7 @@ int futimesat(int dirfd, FAR const char *path, const struct timeval tv[2])
   char fullpath[PATH_MAX];
   int ret;
 
-  ret = lib_getfullpath(dirfd, path, fullpath);
+  ret = lib_getfullpath(dirfd, path, fullpath, sizeof(fullpath));
   if (ret < 0)
     {
       set_errno(-ret);