cifs: fix error handling when calling cifs_parse_devname

When we allowed separate unc= and prefixpath= mount options, we could
ignore EINVAL errors from cifs_parse_devname. Now that they are
deprecated, we need to check for that as well and fail the mount if it's
malformed.

Also fix a later error message that refers to the unc= option.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>

1 files changed, 13 insertions, 9 deletions

diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 0a7fdc31f253..5b97e56ddbca 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -1258,14 +1258,18 @@ cifs_parse_mount_options(const char *mountdata, const char *devname,
         vol->backupuid_specified = false; /* no backup intent for a user */
         vol->backupgid_specified = false; /* no backup intent for a group */
 
-        /*
-         * For now, we ignore -EINVAL errors under the assumption that the
-         * unc= and prefixpath= options will be usable.
-         */
-        if (cifs_parse_devname(devname, vol) == -ENOMEM) {
-                printk(KERN_ERR "CIFS: Unable to allocate memory to parse "
-                                "device string.\n");
-                goto out_nomem;
+        switch (cifs_parse_devname(devname, vol)) {
+        case 0:
+                break;
+        case -ENOMEM:
+                cifs_dbg(VFS, "Unable to allocate memory for devname.\n");
+                goto cifs_parse_mount_err;
+        case -EINVAL:
+                cifs_dbg(VFS, "Malformed UNC in devname.\n");
+                goto cifs_parse_mount_err;
+        default:
+                cifs_dbg(VFS, "Unknown error parsing devname.\n");
+                goto cifs_parse_mount_err;
         }
 
         while ((data = strsep(&options, separator)) != NULL) {
@@ -1827,7 +1831,7 @@ cifs_parse_mount_options(const char *mountdata, const char *devname,
         }
 #endif
         if (!vol->UNC) {
-                cifs_dbg(VFS, "CIFS mount error: No usable UNC path provided in device string or in unc= option!\n");
+                cifs_dbg(VFS, "CIFS mount error: No usable UNC path provided in device string!\n");
                 goto cifs_parse_mount_err;
         }