1 files changed, 1 insertions, 1 deletions

diff --git a/fs/ceph/super.c b/fs/ceph/super.c
index 7d377c9a5e35..6627b26a800c 100644
--- a/fs/ceph/super.c
+++ b/fs/ceph/super.c
@@ -357,7 +357,7 @@ static int parse_mount_options(struct ceph_mount_options **pfsopt,
         }
         err = -EINVAL;
         dev_name_end--;         /* back up to ':' separator */
-        if (*dev_name_end != ':') {
+        if (dev_name_end < dev_name || *dev_name_end != ':') {
                 pr_err("device name is missing path (no : separator in %s)\n",
                                 dev_name);
                 goto out;