From: Steve French <smfrench@gmail.com>
Date: Sun, 17 Aug 2014 05:22:24 +0000 (-0500)
Subject: CIFS: Possible null ptr deref in SMB2_tcon
X-Git-Tag: firefly_0821_release~3679^2~1560
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=c6bef3b64c1e605f4059189153de3251855846b9;p=firefly-linux-kernel-4.4.55.git

CIFS: Possible null ptr deref in SMB2_tcon

commit 18f39e7be0121317550d03e267e3ebd4dbfbb3ce upstream.

As Raphael Geissert pointed out, tcon_error_exit can dereference tcon
and there is one path in which tcon can be null.

Signed-off-by: Steve French <smfrench@gmail.com>
Reported-by: Raphael Geissert <geissert@debian.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index c7a6fd87bb6e..184c55820d1f 100644
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -809,7 +809,8 @@ tcon_exit:
 tcon_error_exit:
 	if (rsp->hdr.Status == STATUS_BAD_NETWORK_NAME) {
 		cifs_dbg(VFS, "BAD_NETWORK_NAME: %s\n", tree);
-		tcon->bad_network_name = true;
+		if (tcon)
+			tcon->bad_network_name = true;
 	}
 	goto tcon_exit;
 }