linux/net/hsr/hsr_slave.c
Eric Dumazet 2b5b8251bc net: hsr: fix possible NULL deref in hsr_handle_frame()
hsr_port_get_rcu() can return NULL, so we need to be careful.

general protection fault, probably for non-canonical address 0xdffffc0000000006: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000030-0x0000000000000037]
CPU: 1 PID: 10249 Comm: syz-executor.5 Not tainted 5.5.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:__read_once_size include/linux/compiler.h:199 [inline]
RIP: 0010:hsr_addr_is_self+0x86/0x330 net/hsr/hsr_framereg.c:44
Code: 04 00 f3 f3 f3 65 48 8b 04 25 28 00 00 00 48 89 45 d0 31 c0 e8 6b ff 94 f9 4c 89 f2 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 <80> 3c 02 00 0f 85 75 02 00 00 48 8b 43 30 49 39 c6 49 89 47 c0 0f
RSP: 0018:ffffc90000da8a90 EFLAGS: 00010206
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff87e0cc33
RDX: 0000000000000006 RSI: ffffffff87e035d5 RDI: 0000000000000000
RBP: ffffc90000da8b20 R08: ffff88808e7de040 R09: ffffed1015d2707c
R10: ffffed1015d2707b R11: ffff8880ae9383db R12: ffff8880a689bc5e
R13: 1ffff920001b5153 R14: 0000000000000030 R15: ffffc90000da8af8
FS:  00007fd7a42be700(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b32338000 CR3: 00000000a928c000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 hsr_handle_frame+0x1c5/0x630 net/hsr/hsr_slave.c:31
 __netif_receive_skb_core+0xfbc/0x30b0 net/core/dev.c:5099
 __netif_receive_skb_one_core+0xa8/0x1a0 net/core/dev.c:5196
 __netif_receive_skb+0x2c/0x1d0 net/core/dev.c:5312
 process_backlog+0x206/0x750 net/core/dev.c:6144
 napi_poll net/core/dev.c:6582 [inline]
 net_rx_action+0x508/0x1120 net/core/dev.c:6650
 __do_softirq+0x262/0x98c kernel/softirq.c:292
 do_softirq_own_stack+0x2a/0x40 arch/x86/entry/entry_64.S:1082
 </IRQ>

Fixes: c5a7591172 ("net/hsr: Use list_head (and rcu) instead of array for slave devices.")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-02-04 09:27:07 +01:00

200 lines
4.2 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 "hsr_slave.h"
#include <linux/etherdevice.h>
#include <linux/if_arp.h>
#include <linux/if_vlan.h>
#include "hsr_main.h"
#include "hsr_device.h"
#include "hsr_forward.h"
#include "hsr_framereg.h"
static rx_handler_result_t hsr_handle_frame(struct sk_buff **pskb)
{
struct sk_buff *skb = *pskb;
struct hsr_port *port;
u16 protocol;
if (!skb_mac_header_was_set(skb)) {
WARN_ONCE(1, "%s: skb invalid", __func__);
return RX_HANDLER_PASS;
}
rcu_read_lock(); /* hsr->node_db, hsr->ports */
port = hsr_port_get_rcu(skb->dev);
if (!port)
goto finish_pass;
if (hsr_addr_is_self(port->hsr, eth_hdr(skb)->h_source)) {
/* Directly kill frames sent by ourselves */
kfree_skb(skb);
goto finish_consume;
}
protocol = eth_hdr(skb)->h_proto;
if (protocol != htons(ETH_P_PRP) && protocol != htons(ETH_P_HSR))
goto finish_pass;
skb_push(skb, ETH_HLEN);
hsr_forward_skb(skb, port);
finish_consume:
rcu_read_unlock(); /* hsr->node_db, hsr->ports */
return RX_HANDLER_CONSUMED;
finish_pass:
rcu_read_unlock(); /* hsr->node_db, hsr->ports */
return RX_HANDLER_PASS;
}
bool hsr_port_exists(const struct net_device *dev)
{
return rcu_access_pointer(dev->rx_handler) == hsr_handle_frame;
}
static int hsr_check_dev_ok(struct net_device *dev)
{
/* Don't allow HSR on non-ethernet like devices */
if ((dev->flags & IFF_LOOPBACK) || dev->type != ARPHRD_ETHER ||
dev->addr_len != ETH_ALEN) {
netdev_info(dev, "Cannot use loopback or non-ethernet device as HSR slave.\n");
return -EINVAL;
}
/* Don't allow enslaving hsr devices */
if (is_hsr_master(dev)) {
netdev_info(dev, "Cannot create trees of HSR devices.\n");
return -EINVAL;
}
if (hsr_port_exists(dev)) {
netdev_info(dev, "This device is already a HSR slave.\n");
return -EINVAL;
}
if (is_vlan_dev(dev)) {
netdev_info(dev, "HSR on top of VLAN is not yet supported in this driver.\n");
return -EINVAL;
}
if (dev->priv_flags & IFF_DONT_BRIDGE) {
netdev_info(dev, "This device does not support bridging.\n");
return -EOPNOTSUPP;
}
/* HSR over bonded devices has not been tested, but I'm not sure it
* won't work...
*/
return 0;
}
/* Setup device to be added to the HSR bridge. */
static int hsr_portdev_setup(struct net_device *dev, struct hsr_port *port)
{
int res;
dev_hold(dev);
res = dev_set_promiscuity(dev, 1);
if (res)
goto fail_promiscuity;
/* FIXME:
* What does net device "adjacency" mean? Should we do
* res = netdev_master_upper_dev_link(port->dev, port->hsr->dev); ?
*/
res = netdev_rx_handler_register(dev, hsr_handle_frame, port);
if (res)
goto fail_rx_handler;
dev_disable_lro(dev);
return 0;
fail_rx_handler:
dev_set_promiscuity(dev, -1);
fail_promiscuity:
dev_put(dev);
return res;
}
int hsr_add_port(struct hsr_priv *hsr, struct net_device *dev,
enum hsr_port_type type)
{
struct hsr_port *port, *master;
int res;
if (type != HSR_PT_MASTER) {
res = hsr_check_dev_ok(dev);
if (res)
return res;
}
port = hsr_port_get_hsr(hsr, type);
if (port)
return -EBUSY; /* This port already exists */
port = kzalloc(sizeof(*port), GFP_KERNEL);
if (!port)
return -ENOMEM;
if (type != HSR_PT_MASTER) {
res = hsr_portdev_setup(dev, port);
if (res)
goto fail_dev_setup;
}
port->hsr = hsr;
port->dev = dev;
port->type = type;
list_add_tail_rcu(&port->port_list, &hsr->ports);
synchronize_rcu();
master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
netdev_update_features(master->dev);
dev_set_mtu(master->dev, hsr_get_max_mtu(hsr));
return 0;
fail_dev_setup:
kfree(port);
return res;
}
void hsr_del_port(struct hsr_port *port)
{
struct hsr_priv *hsr;
struct hsr_port *master;
hsr = port->hsr;
master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
list_del_rcu(&port->port_list);
if (port != master) {
if (master) {
netdev_update_features(master->dev);
dev_set_mtu(master->dev, hsr_get_max_mtu(hsr));
}
netdev_rx_handler_unregister(port->dev);
dev_set_promiscuity(port->dev, -1);
}
/* FIXME?
* netdev_upper_dev_unlink(port->dev, port->hsr->dev);
*/
synchronize_rcu();
if (port != master)
dev_put(port->dev);
kfree(port);
}