linux_dsm_epyc7002/net/hsr/hsr_netlink.c
Taehee Yoo de0083c7ed hsr: avoid to create proc file after unregister
When an interface is being deleted, "/proc/net/dev_snmp6/<interface name>"
is deleted.
The function for this is addrconf_ifdown() in the addrconf_notify() and
it is called by notification, which is NETDEV_UNREGISTER.
But, if NETDEV_CHANGEMTU is triggered after NETDEV_UNREGISTER,
this proc file will be created again.
This recreated proc file will be deleted by netdev_wati_allrefs().
Before netdev_wait_allrefs() is called, creating a new HSR interface
routine can be executed and It tries to create a proc file but it will
find an un-deleted proc file.
At this point, it warns about it.

To avoid this situation, it can use ->dellink() instead of
->ndo_uninit() to release resources because ->dellink() is called
before NETDEV_UNREGISTER.
So, a proc file will not be recreated.

Test commands
    ip link add dummy0 type dummy
    ip link add dummy1 type dummy
    ip link set dummy0 mtu 1300

    #SHELL1
    while :
    do
        ip link add hsr0 type hsr slave1 dummy0 slave2 dummy1
    done

    #SHELL2
    while :
    do
        ip link del hsr0
    done

Splat looks like:
[ 9888.980852][ T2752] proc_dir_entry 'dev_snmp6/hsr0' already registered
[ 9888.981797][    C2] WARNING: CPU: 2 PID: 2752 at fs/proc/generic.c:372 proc_register+0x2d5/0x430
[ 9888.981798][    C2] Modules linked in: hsr dummy veth openvswitch nsh nf_conncount nf_nat nf_conntrack nf_defrag_ipv6x
[ 9888.981814][    C2] CPU: 2 PID: 2752 Comm: ip Tainted: G        W         5.8.0-rc1+ #616
[ 9888.981815][    C2] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
[ 9888.981816][    C2] RIP: 0010:proc_register+0x2d5/0x430
[ 9888.981818][    C2] Code: fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 65 01 00 00 49 8b b5 e0 00 00 00 48 89 ea 40
[ 9888.981819][    C2] RSP: 0018:ffff8880628dedf0 EFLAGS: 00010286
[ 9888.981821][    C2] RAX: dffffc0000000008 RBX: ffff888028c69170 RCX: ffffffffaae09a62
[ 9888.981822][    C2] RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffff88806c9f75ac
[ 9888.981823][    C2] RBP: ffff888028c693f4 R08: ffffed100d9401bd R09: ffffed100d9401bd
[ 9888.981824][    C2] R10: ffffffffaddf406f R11: 0000000000000001 R12: ffff888028c69308
[ 9888.981825][    C2] R13: ffff8880663584c8 R14: dffffc0000000000 R15: ffffed100518d27e
[ 9888.981827][    C2] FS:  00007f3876b3b0c0(0000) GS:ffff88806c800000(0000) knlGS:0000000000000000
[ 9888.981828][    C2] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 9888.981829][    C2] CR2: 00007f387601a8c0 CR3: 000000004101a002 CR4: 00000000000606e0
[ 9888.981830][    C2] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 9888.981831][    C2] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 9888.981832][    C2] Call Trace:
[ 9888.981833][    C2]  ? snmp6_seq_show+0x180/0x180
[ 9888.981834][    C2]  proc_create_single_data+0x7c/0xa0
[ 9888.981835][    C2]  snmp6_register_dev+0xb0/0x130
[ 9888.981836][    C2]  ipv6_add_dev+0x4b7/0xf60
[ 9888.981837][    C2]  addrconf_notify+0x684/0x1ca0
[ 9888.981838][    C2]  ? __mutex_unlock_slowpath+0xd0/0x670
[ 9888.981839][    C2]  ? kasan_unpoison_shadow+0x30/0x40
[ 9888.981840][    C2]  ? wait_for_completion+0x250/0x250
[ 9888.981841][    C2]  ? inet6_ifinfo_notify+0x100/0x100
[ 9888.981842][    C2]  ? dropmon_net_event+0x227/0x410
[ 9888.981843][    C2]  ? notifier_call_chain+0x90/0x160
[ 9888.981844][    C2]  ? inet6_ifinfo_notify+0x100/0x100
[ 9888.981845][    C2]  notifier_call_chain+0x90/0x160
[ 9888.981846][    C2]  register_netdevice+0xbe5/0x1070
[ ... ]

Reported-by: syzbot+1d51c8b74efa4c44adeb@syzkaller.appspotmail.com
Fixes: e0a4b99773 ("hsr: use upper/lower device infrastructure")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-22 20:42:23 -07:00

532 lines
12 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
*
* Routines for handling Netlink messages for HSR.
*/
#include "hsr_netlink.h"
#include <linux/kernel.h>
#include <net/rtnetlink.h>
#include <net/genetlink.h>
#include "hsr_main.h"
#include "hsr_device.h"
#include "hsr_framereg.h"
static const struct nla_policy hsr_policy[IFLA_HSR_MAX + 1] = {
[IFLA_HSR_SLAVE1] = { .type = NLA_U32 },
[IFLA_HSR_SLAVE2] = { .type = NLA_U32 },
[IFLA_HSR_MULTICAST_SPEC] = { .type = NLA_U8 },
[IFLA_HSR_VERSION] = { .type = NLA_U8 },
[IFLA_HSR_SUPERVISION_ADDR] = { .len = ETH_ALEN },
[IFLA_HSR_SEQ_NR] = { .type = NLA_U16 },
};
/* Here, it seems a netdevice has already been allocated for us, and the
* hsr_dev_setup routine has been executed. Nice!
*/
static int hsr_newlink(struct net *src_net, struct net_device *dev,
struct nlattr *tb[], struct nlattr *data[],
struct netlink_ext_ack *extack)
{
struct net_device *link[2];
unsigned char multicast_spec, hsr_version;
if (!data) {
NL_SET_ERR_MSG_MOD(extack, "No slave devices specified");
return -EINVAL;
}
if (!data[IFLA_HSR_SLAVE1]) {
NL_SET_ERR_MSG_MOD(extack, "Slave1 device not specified");
return -EINVAL;
}
link[0] = __dev_get_by_index(src_net,
nla_get_u32(data[IFLA_HSR_SLAVE1]));
if (!link[0]) {
NL_SET_ERR_MSG_MOD(extack, "Slave1 does not exist");
return -EINVAL;
}
if (!data[IFLA_HSR_SLAVE2]) {
NL_SET_ERR_MSG_MOD(extack, "Slave2 device not specified");
return -EINVAL;
}
link[1] = __dev_get_by_index(src_net,
nla_get_u32(data[IFLA_HSR_SLAVE2]));
if (!link[1]) {
NL_SET_ERR_MSG_MOD(extack, "Slave2 does not exist");
return -EINVAL;
}
if (link[0] == link[1]) {
NL_SET_ERR_MSG_MOD(extack, "Slave1 and Slave2 are same");
return -EINVAL;
}
if (!data[IFLA_HSR_MULTICAST_SPEC])
multicast_spec = 0;
else
multicast_spec = nla_get_u8(data[IFLA_HSR_MULTICAST_SPEC]);
if (!data[IFLA_HSR_VERSION]) {
hsr_version = 0;
} else {
hsr_version = nla_get_u8(data[IFLA_HSR_VERSION]);
if (hsr_version > 1) {
NL_SET_ERR_MSG_MOD(extack,
"Only versions 0..1 are supported");
return -EINVAL;
}
}
return hsr_dev_finalize(dev, link, multicast_spec, hsr_version, extack);
}
static void hsr_dellink(struct net_device *dev, struct list_head *head)
{
struct hsr_priv *hsr = netdev_priv(dev);
del_timer_sync(&hsr->prune_timer);
del_timer_sync(&hsr->announce_timer);
hsr_debugfs_term(hsr);
hsr_del_ports(hsr);
hsr_del_self_node(hsr);
hsr_del_nodes(&hsr->node_db);
unregister_netdevice_queue(dev, head);
}
static int hsr_fill_info(struct sk_buff *skb, const struct net_device *dev)
{
struct hsr_priv *hsr = netdev_priv(dev);
struct hsr_port *port;
port = hsr_port_get_hsr(hsr, HSR_PT_SLAVE_A);
if (port) {
if (nla_put_u32(skb, IFLA_HSR_SLAVE1, port->dev->ifindex))
goto nla_put_failure;
}
port = hsr_port_get_hsr(hsr, HSR_PT_SLAVE_B);
if (port) {
if (nla_put_u32(skb, IFLA_HSR_SLAVE2, port->dev->ifindex))
goto nla_put_failure;
}
if (nla_put(skb, IFLA_HSR_SUPERVISION_ADDR, ETH_ALEN,
hsr->sup_multicast_addr) ||
nla_put_u16(skb, IFLA_HSR_SEQ_NR, hsr->sequence_nr))
goto nla_put_failure;
return 0;
nla_put_failure:
return -EMSGSIZE;
}
static struct rtnl_link_ops hsr_link_ops __read_mostly = {
.kind = "hsr",
.maxtype = IFLA_HSR_MAX,
.policy = hsr_policy,
.priv_size = sizeof(struct hsr_priv),
.setup = hsr_dev_setup,
.newlink = hsr_newlink,
.dellink = hsr_dellink,
.fill_info = hsr_fill_info,
};
/* attribute policy */
static const struct nla_policy hsr_genl_policy[HSR_A_MAX + 1] = {
[HSR_A_NODE_ADDR] = { .len = ETH_ALEN },
[HSR_A_NODE_ADDR_B] = { .len = ETH_ALEN },
[HSR_A_IFINDEX] = { .type = NLA_U32 },
[HSR_A_IF1_AGE] = { .type = NLA_U32 },
[HSR_A_IF2_AGE] = { .type = NLA_U32 },
[HSR_A_IF1_SEQ] = { .type = NLA_U16 },
[HSR_A_IF2_SEQ] = { .type = NLA_U16 },
};
static struct genl_family hsr_genl_family;
static const struct genl_multicast_group hsr_mcgrps[] = {
{ .name = "hsr-network", },
};
/* This is called if for some node with MAC address addr, we only get frames
* over one of the slave interfaces. This would indicate an open network ring
* (i.e. a link has failed somewhere).
*/
void hsr_nl_ringerror(struct hsr_priv *hsr, unsigned char addr[ETH_ALEN],
struct hsr_port *port)
{
struct sk_buff *skb;
void *msg_head;
struct hsr_port *master;
int res;
skb = genlmsg_new(NLMSG_GOODSIZE, GFP_ATOMIC);
if (!skb)
goto fail;
msg_head = genlmsg_put(skb, 0, 0, &hsr_genl_family, 0,
HSR_C_RING_ERROR);
if (!msg_head)
goto nla_put_failure;
res = nla_put(skb, HSR_A_NODE_ADDR, ETH_ALEN, addr);
if (res < 0)
goto nla_put_failure;
res = nla_put_u32(skb, HSR_A_IFINDEX, port->dev->ifindex);
if (res < 0)
goto nla_put_failure;
genlmsg_end(skb, msg_head);
genlmsg_multicast(&hsr_genl_family, skb, 0, 0, GFP_ATOMIC);
return;
nla_put_failure:
kfree_skb(skb);
fail:
rcu_read_lock();
master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
netdev_warn(master->dev, "Could not send HSR ring error message\n");
rcu_read_unlock();
}
/* This is called when we haven't heard from the node with MAC address addr for
* some time (just before the node is removed from the node table/list).
*/
void hsr_nl_nodedown(struct hsr_priv *hsr, unsigned char addr[ETH_ALEN])
{
struct sk_buff *skb;
void *msg_head;
struct hsr_port *master;
int res;
skb = genlmsg_new(NLMSG_GOODSIZE, GFP_ATOMIC);
if (!skb)
goto fail;
msg_head = genlmsg_put(skb, 0, 0, &hsr_genl_family, 0, HSR_C_NODE_DOWN);
if (!msg_head)
goto nla_put_failure;
res = nla_put(skb, HSR_A_NODE_ADDR, ETH_ALEN, addr);
if (res < 0)
goto nla_put_failure;
genlmsg_end(skb, msg_head);
genlmsg_multicast(&hsr_genl_family, skb, 0, 0, GFP_ATOMIC);
return;
nla_put_failure:
kfree_skb(skb);
fail:
rcu_read_lock();
master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
netdev_warn(master->dev, "Could not send HSR node down\n");
rcu_read_unlock();
}
/* HSR_C_GET_NODE_STATUS lets userspace query the internal HSR node table
* about the status of a specific node in the network, defined by its MAC
* address.
*
* Input: hsr ifindex, node mac address
* Output: hsr ifindex, node mac address (copied from request),
* age of latest frame from node over slave 1, slave 2 [ms]
*/
static int hsr_get_node_status(struct sk_buff *skb_in, struct genl_info *info)
{
/* For receiving */
struct nlattr *na;
struct net_device *hsr_dev;
/* For sending */
struct sk_buff *skb_out;
void *msg_head;
struct hsr_priv *hsr;
struct hsr_port *port;
unsigned char hsr_node_addr_b[ETH_ALEN];
int hsr_node_if1_age;
u16 hsr_node_if1_seq;
int hsr_node_if2_age;
u16 hsr_node_if2_seq;
int addr_b_ifindex;
int res;
if (!info)
goto invalid;
na = info->attrs[HSR_A_IFINDEX];
if (!na)
goto invalid;
na = info->attrs[HSR_A_NODE_ADDR];
if (!na)
goto invalid;
rcu_read_lock();
hsr_dev = dev_get_by_index_rcu(genl_info_net(info),
nla_get_u32(info->attrs[HSR_A_IFINDEX]));
if (!hsr_dev)
goto rcu_unlock;
if (!is_hsr_master(hsr_dev))
goto rcu_unlock;
/* Send reply */
skb_out = genlmsg_new(NLMSG_GOODSIZE, GFP_ATOMIC);
if (!skb_out) {
res = -ENOMEM;
goto fail;
}
msg_head = genlmsg_put(skb_out, NETLINK_CB(skb_in).portid,
info->snd_seq, &hsr_genl_family, 0,
HSR_C_SET_NODE_STATUS);
if (!msg_head) {
res = -ENOMEM;
goto nla_put_failure;
}
res = nla_put_u32(skb_out, HSR_A_IFINDEX, hsr_dev->ifindex);
if (res < 0)
goto nla_put_failure;
hsr = netdev_priv(hsr_dev);
res = hsr_get_node_data(hsr,
(unsigned char *)
nla_data(info->attrs[HSR_A_NODE_ADDR]),
hsr_node_addr_b,
&addr_b_ifindex,
&hsr_node_if1_age,
&hsr_node_if1_seq,
&hsr_node_if2_age,
&hsr_node_if2_seq);
if (res < 0)
goto nla_put_failure;
res = nla_put(skb_out, HSR_A_NODE_ADDR, ETH_ALEN,
nla_data(info->attrs[HSR_A_NODE_ADDR]));
if (res < 0)
goto nla_put_failure;
if (addr_b_ifindex > -1) {
res = nla_put(skb_out, HSR_A_NODE_ADDR_B, ETH_ALEN,
hsr_node_addr_b);
if (res < 0)
goto nla_put_failure;
res = nla_put_u32(skb_out, HSR_A_ADDR_B_IFINDEX,
addr_b_ifindex);
if (res < 0)
goto nla_put_failure;
}
res = nla_put_u32(skb_out, HSR_A_IF1_AGE, hsr_node_if1_age);
if (res < 0)
goto nla_put_failure;
res = nla_put_u16(skb_out, HSR_A_IF1_SEQ, hsr_node_if1_seq);
if (res < 0)
goto nla_put_failure;
port = hsr_port_get_hsr(hsr, HSR_PT_SLAVE_A);
if (port)
res = nla_put_u32(skb_out, HSR_A_IF1_IFINDEX,
port->dev->ifindex);
if (res < 0)
goto nla_put_failure;
res = nla_put_u32(skb_out, HSR_A_IF2_AGE, hsr_node_if2_age);
if (res < 0)
goto nla_put_failure;
res = nla_put_u16(skb_out, HSR_A_IF2_SEQ, hsr_node_if2_seq);
if (res < 0)
goto nla_put_failure;
port = hsr_port_get_hsr(hsr, HSR_PT_SLAVE_B);
if (port)
res = nla_put_u32(skb_out, HSR_A_IF2_IFINDEX,
port->dev->ifindex);
if (res < 0)
goto nla_put_failure;
rcu_read_unlock();
genlmsg_end(skb_out, msg_head);
genlmsg_unicast(genl_info_net(info), skb_out, info->snd_portid);
return 0;
rcu_unlock:
rcu_read_unlock();
invalid:
netlink_ack(skb_in, nlmsg_hdr(skb_in), -EINVAL, NULL);
return 0;
nla_put_failure:
kfree_skb(skb_out);
/* Fall through */
fail:
rcu_read_unlock();
return res;
}
/* Get a list of MacAddressA of all nodes known to this node (including self).
*/
static int hsr_get_node_list(struct sk_buff *skb_in, struct genl_info *info)
{
unsigned char addr[ETH_ALEN];
struct net_device *hsr_dev;
struct sk_buff *skb_out;
struct hsr_priv *hsr;
bool restart = false;
struct nlattr *na;
void *pos = NULL;
void *msg_head;
int res;
if (!info)
goto invalid;
na = info->attrs[HSR_A_IFINDEX];
if (!na)
goto invalid;
rcu_read_lock();
hsr_dev = dev_get_by_index_rcu(genl_info_net(info),
nla_get_u32(info->attrs[HSR_A_IFINDEX]));
if (!hsr_dev)
goto rcu_unlock;
if (!is_hsr_master(hsr_dev))
goto rcu_unlock;
restart:
/* Send reply */
skb_out = genlmsg_new(GENLMSG_DEFAULT_SIZE, GFP_ATOMIC);
if (!skb_out) {
res = -ENOMEM;
goto fail;
}
msg_head = genlmsg_put(skb_out, NETLINK_CB(skb_in).portid,
info->snd_seq, &hsr_genl_family, 0,
HSR_C_SET_NODE_LIST);
if (!msg_head) {
res = -ENOMEM;
goto nla_put_failure;
}
if (!restart) {
res = nla_put_u32(skb_out, HSR_A_IFINDEX, hsr_dev->ifindex);
if (res < 0)
goto nla_put_failure;
}
hsr = netdev_priv(hsr_dev);
if (!pos)
pos = hsr_get_next_node(hsr, NULL, addr);
while (pos) {
res = nla_put(skb_out, HSR_A_NODE_ADDR, ETH_ALEN, addr);
if (res < 0) {
if (res == -EMSGSIZE) {
genlmsg_end(skb_out, msg_head);
genlmsg_unicast(genl_info_net(info), skb_out,
info->snd_portid);
restart = true;
goto restart;
}
goto nla_put_failure;
}
pos = hsr_get_next_node(hsr, pos, addr);
}
rcu_read_unlock();
genlmsg_end(skb_out, msg_head);
genlmsg_unicast(genl_info_net(info), skb_out, info->snd_portid);
return 0;
rcu_unlock:
rcu_read_unlock();
invalid:
netlink_ack(skb_in, nlmsg_hdr(skb_in), -EINVAL, NULL);
return 0;
nla_put_failure:
nlmsg_free(skb_out);
/* Fall through */
fail:
rcu_read_unlock();
return res;
}
static const struct genl_ops hsr_ops[] = {
{
.cmd = HSR_C_GET_NODE_STATUS,
.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
.flags = 0,
.doit = hsr_get_node_status,
.dumpit = NULL,
},
{
.cmd = HSR_C_GET_NODE_LIST,
.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
.flags = 0,
.doit = hsr_get_node_list,
.dumpit = NULL,
},
};
static struct genl_family hsr_genl_family __ro_after_init = {
.hdrsize = 0,
.name = "HSR",
.version = 1,
.maxattr = HSR_A_MAX,
.policy = hsr_genl_policy,
.netnsok = true,
.module = THIS_MODULE,
.ops = hsr_ops,
.n_ops = ARRAY_SIZE(hsr_ops),
.mcgrps = hsr_mcgrps,
.n_mcgrps = ARRAY_SIZE(hsr_mcgrps),
};
int __init hsr_netlink_init(void)
{
int rc;
rc = rtnl_link_register(&hsr_link_ops);
if (rc)
goto fail_rtnl_link_register;
rc = genl_register_family(&hsr_genl_family);
if (rc)
goto fail_genl_register_family;
hsr_debugfs_create_root();
return 0;
fail_genl_register_family:
rtnl_link_unregister(&hsr_link_ops);
fail_rtnl_link_register:
return rc;
}
void __exit hsr_netlink_exit(void)
{
genl_unregister_family(&hsr_genl_family);
rtnl_link_unregister(&hsr_link_ops);
}
MODULE_ALIAS_RTNL_LINK("hsr");