From fd75247c618e7356b2a2c37ed89cdffd39abc0a5 Mon Sep 17 00:00:00 2001
From: Ronnie Sahlberg <lsahlber@redhat.com>
Date: Fri, 8 Sep 2017 10:37:35 +1000
Subject: [PATCH] cifs: check rsp for NULL before dereferencing in SMB2_open
Git-commit: bf2afee14e07de16d3cafc67edbfc2a3cc65e4bc
Patch-mainline: v4.14-rc2
References: bsc#1085536
In SMB2_open there are several paths where the SendReceive2
call will return an error before it sets rsp_iov.iov_base
thus leaving iov_base uninitialized.
Thus we need to check rsp before we dereference it in
the call to get_rfc1002_length().
A report of this issue was previously reported in
http://www.spinics.net/lists/linux-cifs/msg12846.html
RH-bugzilla : 1476151
Version 2 :
* Lets properly initialize rsp_iov before we use it.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>.
Signed-off-by: Steve French <smfrench@gmail.com>
Reported-by: Xiaoli Feng <xifeng@redhat.com>
Cc: Stable <stable@vger.kernel.org>
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 91ac930a006e..7287c64d4050 100644
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -1612,7 +1612,7 @@ SMB2_open(const unsigned int xid, struct cifs_open_parms *oparms, __le16 *path,
struct cifs_tcon *tcon = oparms->tcon;
struct cifs_ses *ses = tcon->ses;
struct kvec iov[4];
- struct kvec rsp_iov;
+ struct kvec rsp_iov = {NULL, 0};
int resp_buftype;
int uni_path_len;
__le16 *copy_path = NULL;
@@ -1741,7 +1741,7 @@ SMB2_open(const unsigned int xid, struct cifs_open_parms *oparms, __le16 *path,
if (rc != 0) {
cifs_stats_fail_inc(tcon, SMB2_CREATE_HE);
- if (err_buf)
+ if (err_buf && rsp)
*err_buf = kmemdup(rsp, get_rfc1002_length(rsp) + 4,
GFP_KERNEL);
goto creat_exit;
--
2.13.6