android_kernel_xiaomi_sm8350/net/tipc/netlink.c
Allan Stephens 59f0c4523f tipc: Fix skb_under_panic when configuring TIPC without privileges
This patch prevents a TIPC configuration command requiring network
administrator privileges from triggering an skbuff underrun if it
is issued by a process lacking those privileges.  The revised error
handling code avoids the use of a potentially uninitialized global
variable by transforming the unauthorized command into a new command,
then following the standard command processing path to generate the
required error message.

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-05-21 14:52:30 -07:00

115 lines
3.4 KiB
C

/*
* net/tipc/netlink.c: TIPC configuration handling
*
* Copyright (c) 2005-2006, Ericsson AB
* Copyright (c) 2005-2007, Wind River Systems
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the names of the copyright holders nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* Alternatively, this software may be distributed under the terms of the
* GNU General Public License ("GPL") version 2 as published by the Free
* Software Foundation.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include "core.h"
#include "config.h"
#include <net/genetlink.h>
static int handle_cmd(struct sk_buff *skb, struct genl_info *info)
{
struct sk_buff *rep_buf;
struct nlmsghdr *rep_nlh;
struct nlmsghdr *req_nlh = info->nlhdr;
struct tipc_genlmsghdr *req_userhdr = info->userhdr;
int hdr_space = NLMSG_SPACE(GENL_HDRLEN + TIPC_GENL_HDRLEN);
u16 cmd;
if ((req_userhdr->cmd & 0xC000) && (!capable(CAP_NET_ADMIN)))
cmd = TIPC_CMD_NOT_NET_ADMIN;
else
cmd = req_userhdr->cmd;
rep_buf = tipc_cfg_do_cmd(req_userhdr->dest, cmd,
NLMSG_DATA(req_nlh) + GENL_HDRLEN + TIPC_GENL_HDRLEN,
NLMSG_PAYLOAD(req_nlh, GENL_HDRLEN + TIPC_GENL_HDRLEN),
hdr_space);
if (rep_buf) {
skb_push(rep_buf, hdr_space);
rep_nlh = nlmsg_hdr(rep_buf);
memcpy(rep_nlh, req_nlh, hdr_space);
rep_nlh->nlmsg_len = rep_buf->len;
genlmsg_unicast(rep_buf, NETLINK_CB(skb).pid);
}
return 0;
}
static struct genl_family family = {
.id = GENL_ID_GENERATE,
.name = TIPC_GENL_NAME,
.version = TIPC_GENL_VERSION,
.hdrsize = TIPC_GENL_HDRLEN,
.maxattr = 0,
};
static struct genl_ops ops = {
.cmd = TIPC_GENL_CMD,
.doit = handle_cmd,
};
static int family_registered = 0;
int tipc_netlink_start(void)
{
if (genl_register_family(&family))
goto err;
family_registered = 1;
if (genl_register_ops(&family, &ops))
goto err_unregister;
return 0;
err_unregister:
genl_unregister_family(&family);
family_registered = 0;
err:
err("Failed to register netlink interface\n");
return -EFAULT;
}
void tipc_netlink_stop(void)
{
if (family_registered) {
genl_unregister_family(&family);
family_registered = 0;
}
}