From db3b5474f462e77b82ca1e27627f03c47b622c99 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Aur=C3=A9lien=20Aptel?= <aaptel@suse.com>
Date: Wed, 11 Oct 2017 13:23:36 +0200
Subject: [PATCH] CIFS: Fix NULL pointer deref on SMB2_tcon() failure
Git-commit: db3b5474f462e77b82ca1e27627f03c47b622c99
Patch-mainline: v4.14-rc7
References: bsc#1071009, bsc#1144333

If SendReceive2() fails rsp is set to NULL but is dereferenced in the
error handling code.

Cc: stable@vger.kernel.org
Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Acked-by: Aurelien Aptel <aaptel@suse.com>

---
 fs/cifs/smb2pdu.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index fa17caa56128..3efcd96b52c5 100644
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -1255,7 +1255,7 @@ SMB2_tcon(const unsigned int xid, struct cifs_ses *ses, const char *tree,
 	struct smb2_tree_connect_req *req;
 	struct smb2_tree_connect_rsp *rsp = NULL;
 	struct kvec iov[2];
-	struct kvec rsp_iov;
+	struct kvec rsp_iov = { NULL, 0 };
 	int rc = 0;
 	int resp_buftype;
 	int unc_path_len;
@@ -1372,7 +1372,7 @@ SMB2_tcon(const unsigned int xid, struct cifs_ses *ses, const char *tree,
 	return rc;
 
 tcon_error_exit:
-	if (rsp->hdr.sync_hdr.Status == STATUS_BAD_NETWORK_NAME) {
+	if (rsp && rsp->hdr.sync_hdr.Status == STATUS_BAD_NETWORK_NAME) {
 		cifs_dbg(VFS, "BAD_NETWORK_NAME: %s\n", tree);
 	}
 	goto tcon_exit;
-- 
2.16.4