avoid leaking netlink socket fd to external programs

[elogind.git] / udev / udev-watch.c

diff --git a/udev/udev-watch.c b/udev/udev-watch.c
index dff3de1cb43e043939a40fc8d3809cc81de3fd62..d333476346375a4e377f9031b1000f27ce5c77fc 100644 (file)
--- a/udev/udev-watch.c
+++ b/udev/udev-watch.c
@@ -41,16 +41,9 @@ int inotify_fd = -1;
 void udev_watch_init(struct udev *udev)
 {
        inotify_fd = inotify_init();
-       if (inotify_fd >= 0) {
-               int flags;
-
-               flags = fcntl(inotify_fd, F_GETFD);
-               if (flags < 0)
-                       flags = FD_CLOEXEC;
-               else
-                       flags |= FD_CLOEXEC;
-               fcntl(inotify_fd, F_SETFD, flags);
-       } else if (errno == ENOSYS)
+       if (inotify_fd >= 0)
+               util_set_fd_cloexec(inotify_fd);
+       else if (errno == ENOSYS)
                info(udev, "unable to use inotify, udevd will not monitor rule files changes\n");
        else
                err(udev, "inotify_init failed: %m\n");
@@ -85,6 +78,7 @@ void udev_watch_restore(struct udev *udev)
                while ((ent = readdir(dir)) != NULL) {
                        char path[UTIL_PATH_SIZE];
                        char buf[UTIL_PATH_SIZE];
+                       ssize_t syslen;
                        ssize_t len;
                        struct udev_device *dev;
 
@@ -95,13 +89,13 @@ void udev_watch_restore(struct udev *udev)
                        util_strlcat(path, "/", sizeof(path));
                        util_strlcat(path, ent->d_name, sizeof(path));
 
-                       len = readlink(path, buf, sizeof(buf));
-                       if (len <= 0) {
+                       syslen = util_strlcpy(buf, udev_get_sys_path(udev), sizeof(buf));
+                       len = readlink(path, &buf[syslen], sizeof(buf)-syslen);
+                       if (len <= 0 || len >= (ssize_t)(sizeof(buf)-syslen)) {
                                unlink(path);
                                continue;
                        }
-
-                       buf[len] = '\0';
+                       buf[syslen + len] = '\0';
                        dbg(udev, "old watch to '%s' found\n", buf);
                        dev = udev_device_new_from_syspath(udev, buf);
                        if (dev == NULL) {
@@ -142,7 +136,7 @@ void udev_watch_begin(struct udev *udev, struct udev_device *dev)
        snprintf(filename, sizeof(filename), "%s/.udev/watch/%d", udev_get_dev_path(udev), wd);
        util_create_path(udev, filename);
        unlink(filename);
-       symlink(udev_device_get_syspath(dev), filename);
+       symlink(udev_device_get_devpath(dev), filename);
 
        udev_device_set_watch_handle(dev, wd);
 }
@@ -172,16 +166,17 @@ struct udev_device *udev_watch_lookup(struct udev *udev, int wd)
 {
        char filename[UTIL_PATH_SIZE];
        char buf[UTIL_PATH_SIZE];
+       ssize_t syslen;
        ssize_t len;
 
        if (inotify_fd < 0 || wd < 0)
                return NULL;
 
        snprintf(filename, sizeof(filename), "%s/.udev/watch/%d", udev_get_dev_path(udev), wd);
-       len = readlink(filename, buf, sizeof(buf));
-       if (len > 0) {
-               buf[len] = '\0';
-
+       syslen = util_strlcpy(buf, udev_get_sys_path(udev), sizeof(buf));
+       len = readlink(filename, &buf[syslen], sizeof(buf)-syslen);
+       if (len > 0 || len < (ssize_t)(sizeof(buf)-syslen)) {
+               buf[syslen + len] = '\0';
                return udev_device_new_from_syspath(udev, buf);
        }