smb: client: fix double-free in SMB2_open() replay

commit b55e182 upstream.

A response-bearing attempt can return a replayable error and free its
response buffer. If SMB2_open_init() fails before the next send, cleanup
retains the previous buffer type and frees that response again.

Reset response bookkeeping before each attempt to prevent the stale free.

Fixes: 4f1fffa ("cifs: commands that are retried should have replay flag set")
Cc: stable@vger.kernel.org
Signed-off-by: Henrique Carvalho <henrique.carvalho@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: ocabra

fs/smb/client/smb2pdu.c

@@ -3205,6 +3205,8 @@ SMB2_open(const unsigned int xid, struct cifs_open_parms *oparms, __le16 *path,
 
 replay_again:
 	/* reinitialize for possible replay */
+	resp_buftype = CIFS_NO_BUFFER;
+	memset(&rsp_iov, 0, sizeof(rsp_iov));
 	flags = 0;
 	server = cifs_pick_channel(ses);
 	oparms->replay = !!(retries);