linux/net/hsr/hsr_main.c
Taehee Yoo 8aaefcaa5e hsr: fix slab-out-of-bounds Read in hsr_debugfs_rename()
commit 04b69426d8 upstream.

hsr slave interfaces don't have debugfs directory.
So, hsr_debugfs_rename() shouldn't be called when hsr slave interface name
is changed.

Test commands:
    ip link add dummy0 type dummy
    ip link add dummy1 type dummy
    ip link add hsr0 type hsr slave1 dummy0 slave2 dummy1
    ip link set dummy0 name ap

Splat looks like:
[21071.899367][T22666] ap: renamed from dummy0
[21071.914005][T22666] ==================================================================
[21071.919008][T22666] BUG: KASAN: slab-out-of-bounds in hsr_debugfs_rename+0xaa/0xb0 [hsr]
[21071.923640][T22666] Read of size 8 at addr ffff88805febcd98 by task ip/22666
[21071.926941][T22666]
[21071.927750][T22666] CPU: 0 PID: 22666 Comm: ip Not tainted 5.5.0-rc2+ #240
[21071.929919][T22666] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
[21071.935094][T22666] Call Trace:
[21071.935867][T22666]  dump_stack+0x96/0xdb
[21071.936687][T22666]  ? hsr_debugfs_rename+0xaa/0xb0 [hsr]
[21071.937774][T22666]  print_address_description.constprop.5+0x1be/0x360
[21071.939019][T22666]  ? hsr_debugfs_rename+0xaa/0xb0 [hsr]
[21071.940081][T22666]  ? hsr_debugfs_rename+0xaa/0xb0 [hsr]
[21071.940949][T22666]  __kasan_report+0x12a/0x16f
[21071.941758][T22666]  ? hsr_debugfs_rename+0xaa/0xb0 [hsr]
[21071.942674][T22666]  kasan_report+0xe/0x20
[21071.943325][T22666]  hsr_debugfs_rename+0xaa/0xb0 [hsr]
[21071.944187][T22666]  hsr_netdev_notify+0x1fe/0x9b0 [hsr]
[21071.945052][T22666]  ? __module_text_address+0x13/0x140
[21071.945897][T22666]  notifier_call_chain+0x90/0x160
[21071.946743][T22666]  dev_change_name+0x419/0x840
[21071.947496][T22666]  ? __read_once_size_nocheck.constprop.6+0x10/0x10
[21071.948600][T22666]  ? netdev_adjacent_rename_links+0x280/0x280
[21071.949577][T22666]  ? __read_once_size_nocheck.constprop.6+0x10/0x10
[21071.950672][T22666]  ? lock_downgrade+0x6e0/0x6e0
[21071.951345][T22666]  ? do_setlink+0x811/0x2ef0
[21071.951991][T22666]  do_setlink+0x811/0x2ef0
[21071.952613][T22666]  ? is_bpf_text_address+0x81/0xe0
[ ... ]

Reported-by: syzbot+9328206518f08318a5fd@syzkaller.appspotmail.com
Fixes: 4c2d5e33dc ("hsr: rename debugfs file when interface name is changed")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-17 19:48:32 +01:00

136 lines
3.1 KiB
C

// SPDX-License-Identifier: GPL-2.0
/* Copyright 2011-2014 Autronica Fire and Security AS
*
* Author(s):
* 2011-2014 Arvid Brodin, arvid.brodin@alten.se
*/
#include <linux/netdevice.h>
#include <linux/rculist.h>
#include <linux/timer.h>
#include <linux/etherdevice.h>
#include "hsr_main.h"
#include "hsr_device.h"
#include "hsr_netlink.h"
#include "hsr_framereg.h"
#include "hsr_slave.h"
static int hsr_netdev_notify(struct notifier_block *nb, unsigned long event,
void *ptr)
{
struct net_device *dev;
struct hsr_port *port, *master;
struct hsr_priv *hsr;
int mtu_max;
int res;
dev = netdev_notifier_info_to_dev(ptr);
port = hsr_port_get_rtnl(dev);
if (!port) {
if (!is_hsr_master(dev))
return NOTIFY_DONE; /* Not an HSR device */
hsr = netdev_priv(dev);
port = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
if (!port) {
/* Resend of notification concerning removed device? */
return NOTIFY_DONE;
}
} else {
hsr = port->hsr;
}
switch (event) {
case NETDEV_UP: /* Administrative state DOWN */
case NETDEV_DOWN: /* Administrative state UP */
case NETDEV_CHANGE: /* Link (carrier) state changes */
hsr_check_carrier_and_operstate(hsr);
break;
case NETDEV_CHANGENAME:
if (is_hsr_master(dev))
hsr_debugfs_rename(dev);
break;
case NETDEV_CHANGEADDR:
if (port->type == HSR_PT_MASTER) {
/* This should not happen since there's no
* ndo_set_mac_address() for HSR devices - i.e. not
* supported.
*/
break;
}
master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
if (port->type == HSR_PT_SLAVE_A) {
ether_addr_copy(master->dev->dev_addr, dev->dev_addr);
call_netdevice_notifiers(NETDEV_CHANGEADDR,
master->dev);
}
/* Make sure we recognize frames from ourselves in hsr_rcv() */
port = hsr_port_get_hsr(hsr, HSR_PT_SLAVE_B);
res = hsr_create_self_node(hsr,
master->dev->dev_addr,
port ?
port->dev->dev_addr :
master->dev->dev_addr);
if (res)
netdev_warn(master->dev,
"Could not update HSR node address.\n");
break;
case NETDEV_CHANGEMTU:
if (port->type == HSR_PT_MASTER)
break; /* Handled in ndo_change_mtu() */
mtu_max = hsr_get_max_mtu(port->hsr);
master = hsr_port_get_hsr(port->hsr, HSR_PT_MASTER);
master->dev->mtu = mtu_max;
break;
case NETDEV_UNREGISTER:
hsr_del_port(port);
break;
case NETDEV_PRE_TYPE_CHANGE:
/* HSR works only on Ethernet devices. Refuse slave to change
* its type.
*/
return NOTIFY_BAD;
}
return NOTIFY_DONE;
}
struct hsr_port *hsr_port_get_hsr(struct hsr_priv *hsr, enum hsr_port_type pt)
{
struct hsr_port *port;
hsr_for_each_port(hsr, port)
if (port->type == pt)
return port;
return NULL;
}
static struct notifier_block hsr_nb = {
.notifier_call = hsr_netdev_notify, /* Slave event notifications */
};
static int __init hsr_init(void)
{
int res;
BUILD_BUG_ON(sizeof(struct hsr_tag) != HSR_HLEN);
register_netdevice_notifier(&hsr_nb);
res = hsr_netlink_init();
return res;
}
static void __exit hsr_exit(void)
{
unregister_netdevice_notifier(&hsr_nb);
hsr_netlink_exit();
hsr_debugfs_remove_root();
}
module_init(hsr_init);
module_exit(hsr_exit);
MODULE_LICENSE("GPL");