From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Gustavo A. R. Silva" Subject: [PATCH] cifs: cifssmb: Fix potential NULL pointer dereference Date: Tue, 3 Apr 2018 15:55:12 -0500 Message-ID: <20180403205512.GA28804@embeddedor.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-cifs@vger.kernel.org, samba-technical@lists.samba.org, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" To: Ronnie Sahlberg , Steve French Return-path: Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-cifs.vger.kernel.org tcon->ses is being dereferenced before it is null checked, hence there is a potential null pointer dereference. Fix this by moving the pointer dereference after tcon->ses has been properly null checked. Addresses-Coverity-ID: 1467426 ("Dereference before null check") Fixes: 93012bf98416 ("cifs: add server->vals->header_preamble_size") Signed-off-by: Gustavo A. R. Silva --- fs/cifs/smb2pdu.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c index f7741ce..e5ac474 100644 --- a/fs/cifs/smb2pdu.c +++ b/fs/cifs/smb2pdu.c @@ -3454,7 +3454,7 @@ static int build_qfs_info_req(struct kvec *iov, struct cifs_tcon *tcon, int level, int outbuf_len, u64 persistent_fid, u64 volatile_fid) { - struct TCP_Server_Info *server = tcon->ses->server; + struct TCP_Server_Info *server; int rc; struct smb2_query_info_req *req; unsigned int total_len; @@ -3464,6 +3464,8 @@ build_qfs_info_req(struct kvec *iov, struct cifs_tcon *tcon, int level, if ((tcon->ses == NULL) || (tcon->ses->server == NULL)) return -EIO; + server = tcon->ses->server; + rc = smb2_plain_req_init(SMB2_QUERY_INFO, tcon, (void **) &req, &total_len); if (rc) -- 2.7.4