From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751111AbeDMPNd (ORCPT ); Fri, 13 Apr 2018 11:13:33 -0400 Received: from gateway31.websitewelcome.com ([192.185.144.94]:24970 "EHLO gateway31.websitewelcome.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750923AbeDMPNc (ORCPT ); Fri, 13 Apr 2018 11:13:32 -0400 Date: Fri, 13 Apr 2018 10:13:29 -0500 From: "Gustavo A. R. Silva" To: Ronnie Sahlberg , Steve French Cc: linux-cifs@vger.kernel.org, samba-technical@lists.samba.org, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" Subject: [PATCH] cifs: smb2ops: Fix NULL check in smb2_query_symlink Message-ID: <20180413151329.GA27418@embeddedor.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.24 (2015-08-30) X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - gator4166.hostgator.com X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - embeddedor.com X-BWhitelist: no X-Source-IP: 187.172.31.63 X-Source-L: No X-Exim-ID: 1f70OJ-001fzM-AA X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: (embeddedor) [187.172.31.63]:41094 X-Source-Auth: gustavo@embeddedor.com X-Email-Count: 5 X-Source-Cap: Z3V6aWRpbmU7Z3V6aWRpbmU7Z2F0b3I0MTY2Lmhvc3RnYXRvci5jb20= X-Local-Domain: yes Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The current code null checks variable err_buf, which is always null when it is checked, hence utf16_path is free'd and the function returns -ENOENT everytime it is called, making it impossible for the execution path to reach the following code: err_buf = err_iov.iov_base; Fix this by null checking err_iov.iov_base instead of err_buf. Also, notice that err_buf no longer needs to be initialized to NULL. Addresses-Coverity-ID: 1467876 ("Logically dead code") Fixes: 2d636199e400 ("cifs: Change SMB2_open to return an iov for the error parameter") Signed-off-by: Gustavo A. R. Silva --- fs/cifs/smb2ops.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c index b4ae932..38ebf3f 100644 --- a/fs/cifs/smb2ops.c +++ b/fs/cifs/smb2ops.c @@ -1452,7 +1452,7 @@ smb2_query_symlink(const unsigned int xid, struct cifs_tcon *tcon, struct cifs_open_parms oparms; struct cifs_fid fid; struct kvec err_iov = {NULL, 0}; - struct smb2_err_rsp *err_buf = NULL; + struct smb2_err_rsp *err_buf; struct smb2_symlink_err_rsp *symlink; unsigned int sub_len; unsigned int sub_offset; @@ -1476,7 +1476,7 @@ smb2_query_symlink(const unsigned int xid, struct cifs_tcon *tcon, rc = SMB2_open(xid, &oparms, utf16_path, &oplock, NULL, &err_iov); - if (!rc || !err_buf) { + if (!rc || !err_iov.iov_base) { kfree(utf16_path); return -ENOENT; } -- 2.7.4