chiark / gitweb /
libudev: enumerate: fix NULL-deref for subsystem-matches
[elogind.git] / src / libudev / libudev-enumerate.c
index f0305a488b9f33f573a1e9c8df5cee7eedee4d90..385829d464345bf96705c358e9f26152f725f96d 100644 (file)
@@ -1,13 +1,21 @@
-/*
- * libudev - interface to udev device information
- *
- * Copyright (C) 2008-2010 Kay Sievers <kay.sievers@vrfy.org>
- *
- * This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; either
- * version 2.1 of the License, or (at your option) any later version.
- */
+/***
+  This file is part of systemd.
+
+  Copyright 2008-2012 Kay Sievers <kay@vrfy.org>
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
 
 #include <stdio.h>
 #include <stdlib.h>
@@ -73,6 +81,8 @@ _public_ struct udev_enumerate *udev_enumerate_new(struct udev *udev)
 {
         struct udev_enumerate *udev_enumerate;
 
+        if (udev == NULL)
+                return NULL;
         udev_enumerate = calloc(1, sizeof(struct udev_enumerate));
         if (udev_enumerate == NULL)
                 return NULL;
@@ -260,8 +270,9 @@ _public_ struct udev_list_entry *udev_enumerate_get_list_entry(struct udev_enume
                 return NULL;
         if (!udev_enumerate->devices_uptodate) {
                 unsigned int i;
+                int move_later = -1;
                 unsigned int max;
-                struct syspath *prev = NULL, *move_later = NULL;
+                struct syspath *prev = NULL;
                 size_t move_later_prefix = 0;
 
                 udev_list_cleanup(&udev_enumerate->devices_list);
@@ -293,23 +304,25 @@ _public_ struct udev_list_entry *udev_enumerate_get_list_entry(struct udev_enume
                                 move_later_prefix = devices_delay_later(udev_enumerate->udev, entry->syspath);
 
                                 if (move_later_prefix > 0) {
-                                        move_later = entry;
+                                        move_later = i;
                                         continue;
                                 }
                         }
 
-                        if (move_later &&
-                            strncmp(entry->syspath, move_later->syspath, move_later_prefix) != 0) {
+                        if ((move_later >= 0) &&
+                             !strneq(entry->syspath, udev_enumerate->devices[move_later].syspath, move_later_prefix)) {
 
-                                udev_list_entry_add(&udev_enumerate->devices_list, move_later->syspath, NULL);
-                                move_later = NULL;
+                                udev_list_entry_add(&udev_enumerate->devices_list,
+                                                    udev_enumerate->devices[move_later].syspath, NULL);
+                                move_later = -1;
                         }
 
                         udev_list_entry_add(&udev_enumerate->devices_list, entry->syspath, NULL);
                 }
 
-                if (move_later)
-                        udev_list_entry_add(&udev_enumerate->devices_list, move_later->syspath, NULL);
+                if (move_later >= 0)
+                        udev_list_entry_add(&udev_enumerate->devices_list,
+                                            udev_enumerate->devices[move_later].syspath, NULL);
 
                 /* add and cleanup delayed devices from end of list */
                 for (i = max; i < udev_enumerate->devices_cur; i++) {
@@ -649,11 +662,11 @@ static int scan_dir_and_add_devices(struct udev_enumerate *udev_enumerate,
         struct dirent *dent;
 
         s = path;
-        l = util_strpcpyl(&s, sizeof(path), "/sys/", basedir, NULL);
+        l = strpcpyl(&s, sizeof(path), "/sys/", basedir, NULL);
         if (subdir1 != NULL)
-                l = util_strpcpyl(&s, l, "/", subdir1, NULL);
+                l = strpcpyl(&s, l, "/", subdir1, NULL);
         if (subdir2 != NULL)
-                util_strpcpyl(&s, l, "/", subdir2, NULL);
+                strpcpyl(&s, l, "/", subdir2, NULL);
         dir = opendir(path);
         if (dir == NULL)
                 return -ENOENT;
@@ -667,7 +680,7 @@ static int scan_dir_and_add_devices(struct udev_enumerate *udev_enumerate,
                 if (!match_sysname(udev_enumerate, dent->d_name))
                         continue;
 
-                util_strscpyl(syspath, sizeof(syspath), path, "/", dent->d_name, NULL);
+                strscpyl(syspath, sizeof(syspath), path, "/", dent->d_name, NULL);
                 dev = udev_device_new_from_syspath(udev_enumerate->udev, syspath);
                 if (dev == NULL)
                         continue;
@@ -708,6 +721,8 @@ static bool match_subsystem(struct udev_enumerate *udev_enumerate, const char *s
 {
         struct udev_list_entry *list_entry;
 
+        subsystem = subsystem ? : "";
+
         udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_enumerate->subsystem_nomatch_list)) {
                 if (fnmatch(udev_list_entry_get_name(list_entry), subsystem, 0) == 0)
                         return false;
@@ -728,7 +743,7 @@ static int scan_dir(struct udev_enumerate *udev_enumerate, const char *basedir,
         DIR *dir;
         struct dirent *dent;
 
-        util_strscpyl(path, sizeof(path), "/sys/", basedir, NULL);
+        strscpyl(path, sizeof(path), "/sys/", basedir, NULL);
         dir = opendir(path);
         if (dir == NULL)
                 return -1;
@@ -779,7 +794,7 @@ static int scan_devices_tags(struct udev_enumerate *udev_enumerate)
                 struct dirent *dent;
                 char path[UTIL_PATH_SIZE];
 
-                util_strscpyl(path, sizeof(path), "/run/udev/tags/", udev_list_entry_get_name(list_entry), NULL);
+                strscpyl(path, sizeof(path), "/run/udev/tags/", udev_list_entry_get_name(list_entry), NULL);
                 dir = opendir(path);
                 if (dir == NULL)
                         continue;
@@ -816,23 +831,27 @@ nomatch:
 static int parent_add_child(struct udev_enumerate *enumerate, const char *path)
 {
         struct udev_device *dev;
+        int r = 0;
 
         dev = udev_device_new_from_syspath(enumerate->udev, path);
         if (dev == NULL)
                 return -ENODEV;
 
         if (!match_subsystem(enumerate, udev_device_get_subsystem(dev)))
-                return 0;
+                goto nomatch;
         if (!match_sysname(enumerate, udev_device_get_sysname(dev)))
-                return 0;
+                goto nomatch;
         if (!match_property(enumerate, dev))
-                return 0;
+                goto nomatch;
         if (!match_sysattr(enumerate, dev))
-                return 0;
+                goto nomatch;
 
         syspath_add(enumerate, udev_device_get_syspath(dev));
+        r = 1;
+
+nomatch:
         udev_device_unref(dev);
-        return 1;
+        return r;
 }
 
 static int parent_crawl_children(struct udev_enumerate *enumerate, const char *path, int maxdepth)