fix null deref; vmnt->mounted_on is NULL legitimately for root.

changed check+panic to assert().

added assert().

diff --git a/servers/vfs/path.c b/servers/vfs/path.c
index 05706f7b88338e3fc096fa0e6638f83c0eb3ff8c..1d2f65299b5a00c0cebe866befcb50d66ff1c829 100644 (file)
--- a/servers/vfs/path.c
+++ b/servers/vfs/path.c
@@ -11,6 +11,7 @@
 #include <minix/const.h>
 #include <minix/endpoint.h>
 #include <unistd.h>
+#include <assert.h>
 #include <minix/vfsif.h>
 #include "fproc.h"
 #include "vmnt.h"
@@ -43,6 +44,8 @@ int flags;
   struct vmnt *vmp;
   struct node_details res;
 
+  assert(dirp);
+
   /* Get a free vnode */
   if((new_vp = get_free_vnode()) == NIL_VNODE) return(NIL_VNODE);
   
@@ -238,7 +241,7 @@ node_details_t *node;
                dir_vp = 0;
                /* Start node is now the mounted partition's root node */
                for (vmp = &vmnt[0]; vmp != &vmnt[NR_MNTS]; ++vmp) {
-                       if (vmp->m_dev != NO_DEV) {
+                       if (vmp->m_dev != NO_DEV && vmp->m_mounted_on) {
                           if (vmp->m_mounted_on->v_inode_nr == res.inode_nr &&
                               vmp->m_mounted_on->v_fs_e == res.fs_e) {
                                dir_vp = vmp->m_root_node;
@@ -246,10 +249,7 @@ node_details_t *node;
                           }
                        }
                }
-
-               if (!dir_vp) {
-                       panic("VFS lookup: can't find mounted partition");
-               }
+               assert(dir_vp);
        } else {
                /* Climbing up mount */
                /* Find the vmnt that represents the partition on