Commit bf2afee1 authored Sep 08, 2017 by Ronnie Sahlberg Committed by Steve French Sep 12, 2017

cifs: check rsp for NULL before dereferencing in SMB2_open

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&gt;.>
Signed-off-by: Steve French <smfrench@gmail.com>
Reported-by: Xiaoli Feng <xifeng@redhat.com>
CC: Stable <stable@vger.kernel.org>

parent 52269718

fs/cifs/smb2pdu.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -1634,7 +1634,7 @@ 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;
		@@ -1763,7 +1763,7 @@ 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;

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