Merged in x_qin/nuttx/null_check_for_open_and_write (pull request #498)

fs/vfs:null check for path on open and buf on write

Null path check is depend on CONFIG_DEBUG_FEATURES and CONFIG_DEBUG_ASSERTIONS, added null checking so it's always performed
Added null checking on buf for write()

Approved-by: Gregory Nutt <gnutt@nuttx.org>

fs/vfs/fs_open.c

@@ -99,15 +99,21 @@ int open(const char *path, int oflags, ...)
   int ret;
   int fd;
 
+  /* open() is a cancellation point */
+
+  (void)enter_cancellation_point();
+
+  if (path == NULL)
+    {
+      set_errno(EINVAL);
+      goto errout;
+    }
+
 #ifdef CONFIG_FILE_MODE
 #  ifdef CONFIG_CPP_HAVE_WARNING
 #    warning "File creation not implemented"
 #  endif
 
-  /* open() is a cancellation point */
-
-  (void)enter_cancellation_point();
-
   /* If the file is opened for creation, then get the mode bits */
 
   if ((oflags & (O_WRONLY | O_CREAT)) != 0)

fs/vfs/fs_write.c

@@ -153,6 +153,13 @@ ssize_t write(int fd, FAR const void *buf, size_t nbytes)
 
   (void)enter_cancellation_point();
 
+  if (buf == NULL)
+    {
+      set_errno(EINVAL);
+      ret = ERROR;
+      goto errout;
+    }
+
   /* Did we get a valid file descriptor? */
 
 #if CONFIG_NFILE_DESCRIPTORS > 0
@@ -167,7 +174,7 @@ ssize_t write(int fd, FAR const void *buf, size_t nbytes)
       ret = send(fd, buf, nbytes, 0);
 #else
       set_errno(EBADF);
-      ret = ERROR ERROR;
+      ret = ERROR;
 #endif
     }
 
@@ -202,6 +209,7 @@ ssize_t write(int fd, FAR const void *buf, size_t nbytes)
     }
 #endif
 
+errout:
   leave_cancellation_point();
   return ret;
 }