1 files changed, 8 insertions, 3 deletions
diff --git a/cpukit/libcsupport/src/fchmod.c b/cpukit/libcsupport/src/fchmod.c
index e651066a77..14fb416f68 100644
--- a/cpukit/libcsupport/src/fchmod.c
+++ b/cpukit/libcsupport/src/fchmod.c
@@ -28,9 +28,14 @@ int fchmod( int fd, mode_t mode )
   iop = rtems_libio_iop( fd );
   rtems_libio_check_is_open(iop);
 
-  rtems_filesystem_instance_lock( &iop->pathinfo );
-  rv = (*iop->pathinfo.ops->fchmod_h)( &iop->pathinfo, mode );
-  rtems_filesystem_instance_unlock( &iop->pathinfo );
+  if (iop->pathinfo.mt_entry->writeable) {
+    rtems_filesystem_instance_lock( &iop->pathinfo );
+    rv = (*iop->pathinfo.ops->fchmod_h)( &iop->pathinfo, mode );
+    rtems_filesystem_instance_unlock( &iop->pathinfo );
+  } else {
+    errno = EROFS;
+    rv = -1;
+  }
 
   return rv;
 }