selinux: fix dentry_open() error check

The return value of dentry_open() shoud be checked by IS_ERR().

Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: James Morris <jmorris@namei.org>
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: James Morris <jmorris@namei.org>

diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 8ab5679..28ee187 100644 (file)
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -1754,7 +1754,8 @@ static inline void flush_unauthorized_files(struct files_struct * files)
                                                get_file(devnull);
                                        } else {
                                                devnull = dentry_open(dget(selinux_null), mntget(selinuxfs_mount), O_RDWR);
-                                               if (!devnull) {
+                                               if (IS_ERR(devnull)) {
+                                                       devnull = NULL;
                                                        put_unused_fd(fd);
                                                        fput(file);
                                                        continue;