Re: Don't load kernel modules from the current directory, second diff

[Marc Balmer <mbalmer%NetBSD.org@localhost>]

Thanks to all that replied to my initial diff.  This second version is
better, it allows to load a module from the filesystem with either an
absolute path starting with '/' or a relative path starting with '.'.
So you can still load a module from the CWD using

modload ./mymodule.kmod

module_load_vfs() is changed in two ways:  When a module is loaded from
the path given to modload, it must start with either '.' or '/'.  If a
path is constructed to load the module from the system module area, it
must not start with '.' or '/'.

kobj_load_vfs() will only load an object with a path starting with
either '/' or '.'

Comments?

Index: sys/kern/kern_module_vfs.c
===================================================================
RCS file: /cvsroot/src/sys/kern/kern_module_vfs.c,v
retrieving revision 1.10
diff -u -p -r1.10 kern_module_vfs.c
--- sys/kern/kern_module_vfs.c  28 Nov 2010 00:26:38 -0000      1.10
+++ sys/kern/kern_module_vfs.c  4 Aug 2011 10:34:36 -0000
@@ -77,15 +77,21 @@ module_load_vfs(const char *name, int fl
        path = PNBUF_GET();
 
        if (!autoload) {
-               nochroot = false;
-               snprintf(path, MAXPATHLEN, "%s", name);
-               error = kobj_load_vfs(&mod->mod_kobj, path, nochroot);
+               if (*name == '/' || *name == '.') {
+                       nochroot = false;
+                       snprintf(path, MAXPATHLEN, "%s", name);
+                       error = kobj_load_vfs(&mod->mod_kobj, path, nochroot);
+               } else
+                       error = ENOENT;
        }
        if (autoload || (error == ENOENT)) {
-               nochroot = true;
-               snprintf(path, MAXPATHLEN, "%s/%s/%s.kmod",
-                   module_base, name, name);
-               error = kobj_load_vfs(&mod->mod_kobj, path, nochroot);
+               if (*name != '/' && *name != '.') {
+                       nochroot = true;
+                       snprintf(path, MAXPATHLEN, "%s/%s/%s.kmod",
+                           module_base, name, name);
+                       error = kobj_load_vfs(&mod->mod_kobj, path, nochroot);
+               } else
+                       error = ENOENT;
        }
        if (error != 0) {
                PNBUF_PUT(path);
Index: sys/kern/subr_kobj_vfs.c
===================================================================
RCS file: /cvsroot/src/sys/kern/subr_kobj_vfs.c,v
retrieving revision 1.4
diff -u -p -r1.4 subr_kobj_vfs.c
--- sys/kern/subr_kobj_vfs.c    19 Nov 2010 06:44:43 -0000      1.4
+++ sys/kern/subr_kobj_vfs.c    4 Aug 2011 10:34:36 -0000
@@ -139,6 +139,10 @@ kobj_load_vfs(kobj_t *kop, const char *p
        int error;
        kobj_t ko;
 
+       KASSERT(path != NULL);
+       if (*path != '/' && *path != '.')
+               return ENOENT;
+
        cred = kauth_cred_get();
 
        ko = kmem_zalloc(sizeof(*ko), KM_SLEEP);