[PATCH] CIFS: handle guest access errors to Windows shares

[Mark Syms <mark.syms-Sxgqhf6Nn4DQT0dZR+AlfA@public.gmane.org>]

Commit 1a967d6c9b39c226be1b45f13acd4d8a5ab3dc44 ("correctly to
anonymous authentication for the NTLM(v2) authentication") introduces
a regression in handling errors related to attempting a guest
connection to a Windows share which requires authentication. This
should result in a permission denied error but actually causes the
kernel module to enter a never-ending loop trying to follow a DFS
referal which doesn't exist.

The base cause of this is the failure now occurs later in the process
during tree connect and not at the session setup setup and all errors
in tree connect are interpreted as needing to follow the DFS paths
which isn't in this case correct. So, check the returned error against
EACCES and fail if this is returned error.
---
 fs/cifs/connect.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 4547aed..a1737aa 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -3651,6 +3651,9 @@ cifs_mount(struct cifs_sb_info *cifs_sb, struct smb_vol *volume_info)
 	if (IS_ERR(tcon)) {
 		rc = PTR_ERR(tcon);
 		tcon = NULL;
+		if (rc == -EACCES) {
+			goto mount_fail_check;
+		}
 		goto remote_path_check;
 	}
 
-- 
2.10.2