From: Thomas Werschlein <thomas.werschlein@geo.uzh.ch>
Date: Thu, 30 Aug 2018 16:29:20 +0000 (+0200)
Subject: cifs: connect to servername instead of IP for IPC$ share
X-Git-Tag: v4.18.9~141
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=15c4b1902f0e35dd51bb79fca73c50b6d14df699;p=thirdparty%2Fkernel%2Fstable.git

cifs: connect to servername instead of IP for IPC$ share

commit 395a2076b4064f97d3fce03af15210ff2a7bb7f9 upstream.

This patch is required allows access to a Microsoft fileserver failover
cluster behind a 1:1 NAT firewall.

The change also provides stronger context for authentication and share
connection (see MS-SMB2 3.3.5.7 and MS-SRVS 3.1.6.8) as noted by
Tom Talpey, and addresses comments about the buffer size for the UNC
made by Aurélien Aptel.

Signed-off-by: Thomas Werschlein <thomas.werschlein@geo.uzh.ch>
Signed-off-by: Steve French <stfrench@microsoft.com>
CC: Tom Talpey <ttalpey@microsoft.com>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
CC: Stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 9d02563b2147e..44043f809a3c1 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -2523,7 +2523,7 @@ cifs_setup_ipc(struct cifs_ses *ses, struct smb_vol *volume_info)
 	if (tcon == NULL)
 		return -ENOMEM;
 
-	snprintf(unc, sizeof(unc), "\\\\%s\\IPC$", ses->serverName);
+	snprintf(unc, sizeof(unc), "\\\\%s\\IPC$", ses->server->hostname);
 
 	/* cannot fail */
 	nls_codepage = load_nls_default();