[rtems commit] IMFS: Avoid NULL pointer access

[Sebastian Huber]

Module:    rtems
Branch:    master
Commit:    22cd2821de2dcec7117fa0370a495e675de206a4
Changeset: http://git.rtems.org/rtems/commit/?id=22cd2821de2dcec7117fa0370a495e675de206a4

Author:    Sebastian Huber <sebastian.huber at embedded-brains.de>
Date:      Wed Oct  8 11:24:36 2014 +0200

IMFS: Avoid NULL pointer access

Avoid NULL pointer access in IMFS_is_imfs_instance().  File systems
mounted via mount() always have a valid type string.

---

 cpukit/libcsupport/src/__usrenv.c         |    3 ++-
 testsuites/fstests/fsimfsgeneric01/init.c |   11 +++++++++++
 2 files changed, 13 insertions(+), 1 deletions(-)

diff --git a/cpukit/libcsupport/src/__usrenv.c b/cpukit/libcsupport/src/__usrenv.c
index 71efda9..d032aea 100644
--- a/cpukit/libcsupport/src/__usrenv.c
+++ b/cpukit/libcsupport/src/__usrenv.c
@@ -229,7 +229,8 @@ rtems_filesystem_mount_table_entry_t rtems_filesystem_null_mt_entry = {
   .mt_point_node = &rtems_filesystem_global_location_null,
   .mt_fs_root = &rtems_filesystem_global_location_null,
   .mounted = false,
-  .writeable = false
+  .writeable = false,
+  .type = ""
 };
 
 rtems_filesystem_global_location_t rtems_filesystem_global_location_null = {
diff --git a/testsuites/fstests/fsimfsgeneric01/init.c b/testsuites/fstests/fsimfsgeneric01/init.c
index 09e7ed6..40f0aed 100644
--- a/testsuites/fstests/fsimfsgeneric01/init.c
+++ b/testsuites/fstests/fsimfsgeneric01/init.c
@@ -472,6 +472,17 @@ static void test_imfs_make_generic_node_errors(void)
   rtems_test_assert(rv == -1);
   rtems_test_assert(errno == EIO);
   rtems_test_assert(rtems_resource_snapshot_check(&before));
+
+  errno = 0;
+  rv = IMFS_make_generic_node(
+    "/nil/nada",
+    S_IFCHR | S_IRWXU | S_IRWXG | S_IRWXO,
+    &node_control,
+    NULL
+  );
+  rtems_test_assert(rv == -1);
+  rtems_test_assert(errno == ENOENT);
+  rtems_test_assert(rtems_resource_snapshot_check(&before));
 }
 
 static void Init(rtems_task_argument arg)