linux/drivers/scsi/iscsi_tcp.h
David S. Miller 676d23690f net: Fix use after free by removing length arg from sk_data_ready callbacks.
Several spots in the kernel perform a sequence like:

	skb_queue_tail(&sk->s_receive_queue, skb);
	sk->sk_data_ready(sk, skb->len);

But at the moment we place the SKB onto the socket receive queue it
can be consumed and freed up.  So this skb->len access is potentially
to freed up memory.

Furthermore, the skb->len can be modified by the consumer so it is
possible that the value isn't accurate.

And finally, no actual implementation of this callback actually uses
the length argument.  And since nobody actually cared about it's
value, lots of call sites pass arbitrary values in such as '0' and
even '1'.

So just remove the length argument from the callback, that way there
is no confusion whatsoever and all of these use-after-free cases get
fixed as a side effect.

Based upon a patch by Eric Dumazet and his suggestion to audit this
issue tree-wide.

Signed-off-by: David S. Miller <davem@davemloft.net>
2014-04-11 16:15:36 -04:00

69 lines
1.9 KiB
C

/*
* iSCSI Initiator TCP Transport
* Copyright (C) 2004 Dmitry Yusupov
* Copyright (C) 2004 Alex Aizman
* Copyright (C) 2005 - 2006 Mike Christie
* Copyright (C) 2006 Red Hat, Inc. All rights reserved.
* maintained by open-iscsi@googlegroups.com
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published
* by the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* See the file COPYING included with this distribution for more details.
*/
#ifndef ISCSI_SW_TCP_H
#define ISCSI_SW_TCP_H
#include <scsi/libiscsi.h>
#include <scsi/libiscsi_tcp.h>
struct socket;
struct iscsi_tcp_conn;
/* Socket connection send helper */
struct iscsi_sw_tcp_send {
struct iscsi_hdr *hdr;
struct iscsi_segment segment;
struct iscsi_segment data_segment;
};
struct iscsi_sw_tcp_conn {
struct socket *sock;
struct iscsi_sw_tcp_send out;
/* old values for socket callbacks */
void (*old_data_ready)(struct sock *);
void (*old_state_change)(struct sock *);
void (*old_write_space)(struct sock *);
/* data and header digests */
struct hash_desc tx_hash; /* CRC32C (Tx) */
struct hash_desc rx_hash; /* CRC32C (Rx) */
/* MIB custom statistics */
uint32_t sendpage_failures_cnt;
uint32_t discontiguous_hdr_cnt;
ssize_t (*sendpage)(struct socket *, struct page *, int, size_t, int);
};
struct iscsi_sw_tcp_host {
struct iscsi_session *session;
};
struct iscsi_sw_tcp_hdrbuf {
struct iscsi_hdr hdrbuf;
char hdrextbuf[ISCSI_MAX_AHS_SIZE +
ISCSI_DIGEST_SIZE];
};
#endif /* ISCSI_SW_TCP_H */