linux/net/sched/act_tunnel_key.c
Davide Caratti abdadd3cfd net/sched: fix NULL dereference in the error path of tunnel_key_init()
when the following command

 # tc action add action tunnel_key unset index 100

is run for the first time, and tunnel_key_init() fails to allocate struct
tcf_tunnel_key_params, tunnel_key_release() dereferences NULL pointers.
This causes the following error:

 BUG: unable to handle kernel NULL pointer dereference at 0000000000000010
 IP: tunnel_key_release+0xd/0x40 [act_tunnel_key]
 PGD 8000000033787067 P4D 8000000033787067 PUD 74646067 PMD 0
 Oops: 0000 [#1] SMP PTI
 Modules linked in: act_tunnel_key(E) act_csum ip6table_filter ip6_tables iptable_filter binfmt_misc ext4 mbcache jbd2 crct10dif_pclmul crc32_pclmul snd_hda_codec_generic ghash_clmulni_intel snd_hda_intel pcbc snd_hda_codec snd_hda_core snd_hwdep snd_seq aesni_intel snd_seq_device crypto_simd glue_helper snd_pcm cryptd joydev snd_timer pcspkr virtio_balloon snd i2c_piix4 soundcore nfsd auth_rpcgss nfs_acl lockd grace sunrpc ip_tables xfs libcrc32c ata_generic pata_acpi qxl drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops ttm virtio_net virtio_blk drm virtio_console crc32c_intel ata_piix serio_raw i2c_core virtio_pci libata virtio_ring virtio floppy dm_mirror dm_region_hash dm_log dm_mod
 CPU: 2 PID: 3101 Comm: tc Tainted: G            E    4.16.0-rc4.act_vlan.orig+ #403
 Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011
 RIP: 0010:tunnel_key_release+0xd/0x40 [act_tunnel_key]
 RSP: 0018:ffffba46803b7768 EFLAGS: 00010286
 RAX: ffffffffc09010a0 RBX: 0000000000000000 RCX: 0000000000000024
 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff99ee336d7480
 RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000044
 R10: 0000000000000220 R11: ffff99ee79d73131 R12: 0000000000000000
 R13: ffff99ee32d67610 R14: ffff99ee7671dc38 R15: 00000000fffffff4
 FS:  00007febcb2cd740(0000) GS:ffff99ee7fd00000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000000000000010 CR3: 000000007c8e4005 CR4: 00000000001606e0
 Call Trace:
  __tcf_idr_release+0x79/0xf0
  tunnel_key_init+0xd9/0x460 [act_tunnel_key]
  tcf_action_init_1+0x2cc/0x430
  tcf_action_init+0xd3/0x1b0
  tc_ctl_action+0x18b/0x240
  rtnetlink_rcv_msg+0x29c/0x310
  ? _cond_resched+0x15/0x30
  ? __kmalloc_node_track_caller+0x1b9/0x270
  ? rtnl_calcit.isra.28+0x100/0x100
  netlink_rcv_skb+0xd2/0x110
  netlink_unicast+0x17c/0x230
  netlink_sendmsg+0x2cd/0x3c0
  sock_sendmsg+0x30/0x40
  ___sys_sendmsg+0x27a/0x290
  __sys_sendmsg+0x51/0x90
  do_syscall_64+0x6e/0x1a0
  entry_SYSCALL_64_after_hwframe+0x3d/0xa2
 RIP: 0033:0x7febca6deba0
 RSP: 002b:00007ffe7b0dd128 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
 RAX: ffffffffffffffda RBX: 00007ffe7b0dd250 RCX: 00007febca6deba0
 RDX: 0000000000000000 RSI: 00007ffe7b0dd1a0 RDI: 0000000000000003
 RBP: 000000005aaa90cb R08: 0000000000000002 R09: 0000000000000000
 R10: 00007ffe7b0dcba0 R11: 0000000000000246 R12: 0000000000000000
 R13: 00007ffe7b0dd264 R14: 0000000000000001 R15: 0000000000669f60
 Code: 44 00 00 8b 0d b5 23 00 00 48 8b 87 48 10 00 00 48 8b 3c c8 e9 a5 e5 d8 c3 0f 1f 44 00 00 0f 1f 44 00 00 53 48 8b 9f b0 00 00 00 <83> 7b 10 01 74 0b 48 89 df 31 f6 5b e9 f2 fa 7f c3 48 8b 7b 18
 RIP: tunnel_key_release+0xd/0x40 [act_tunnel_key] RSP: ffffba46803b7768
 CR2: 0000000000000010

Fix this in tunnel_key_release(), ensuring 'param' is not NULL before
dereferencing it.

Fixes: d0f6dd8a91 ("net/sched: Introduce act_tunnel_key")
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-17 19:53:28 -04:00

358 lines
9.1 KiB
C

/*
* Copyright (c) 2016, Amir Vadai <amir@vadai.me>
* Copyright (c) 2016, Mellanox Technologies. All rights reserved.
*
* 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.
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/skbuff.h>
#include <linux/rtnetlink.h>
#include <net/netlink.h>
#include <net/pkt_sched.h>
#include <net/dst.h>
#include <linux/tc_act/tc_tunnel_key.h>
#include <net/tc_act/tc_tunnel_key.h>
static unsigned int tunnel_key_net_id;
static struct tc_action_ops act_tunnel_key_ops;
static int tunnel_key_act(struct sk_buff *skb, const struct tc_action *a,
struct tcf_result *res)
{
struct tcf_tunnel_key *t = to_tunnel_key(a);
struct tcf_tunnel_key_params *params;
int action;
rcu_read_lock();
params = rcu_dereference(t->params);
tcf_lastuse_update(&t->tcf_tm);
bstats_cpu_update(this_cpu_ptr(t->common.cpu_bstats), skb);
action = params->action;
switch (params->tcft_action) {
case TCA_TUNNEL_KEY_ACT_RELEASE:
skb_dst_drop(skb);
break;
case TCA_TUNNEL_KEY_ACT_SET:
skb_dst_drop(skb);
skb_dst_set(skb, dst_clone(&params->tcft_enc_metadata->dst));
break;
default:
WARN_ONCE(1, "Bad tunnel_key action %d.\n",
params->tcft_action);
break;
}
rcu_read_unlock();
return action;
}
static const struct nla_policy tunnel_key_policy[TCA_TUNNEL_KEY_MAX + 1] = {
[TCA_TUNNEL_KEY_PARMS] = { .len = sizeof(struct tc_tunnel_key) },
[TCA_TUNNEL_KEY_ENC_IPV4_SRC] = { .type = NLA_U32 },
[TCA_TUNNEL_KEY_ENC_IPV4_DST] = { .type = NLA_U32 },
[TCA_TUNNEL_KEY_ENC_IPV6_SRC] = { .len = sizeof(struct in6_addr) },
[TCA_TUNNEL_KEY_ENC_IPV6_DST] = { .len = sizeof(struct in6_addr) },
[TCA_TUNNEL_KEY_ENC_KEY_ID] = { .type = NLA_U32 },
[TCA_TUNNEL_KEY_ENC_DST_PORT] = {.type = NLA_U16},
[TCA_TUNNEL_KEY_NO_CSUM] = { .type = NLA_U8 },
};
static int tunnel_key_init(struct net *net, struct nlattr *nla,
struct nlattr *est, struct tc_action **a,
int ovr, int bind)
{
struct tc_action_net *tn = net_generic(net, tunnel_key_net_id);
struct nlattr *tb[TCA_TUNNEL_KEY_MAX + 1];
struct tcf_tunnel_key_params *params_old;
struct tcf_tunnel_key_params *params_new;
struct metadata_dst *metadata = NULL;
struct tc_tunnel_key *parm;
struct tcf_tunnel_key *t;
bool exists = false;
__be16 dst_port = 0;
__be64 key_id;
__be16 flags;
int ret = 0;
int err;
if (!nla)
return -EINVAL;
err = nla_parse_nested(tb, TCA_TUNNEL_KEY_MAX, nla, tunnel_key_policy,
NULL);
if (err < 0)
return err;
if (!tb[TCA_TUNNEL_KEY_PARMS])
return -EINVAL;
parm = nla_data(tb[TCA_TUNNEL_KEY_PARMS]);
exists = tcf_idr_check(tn, parm->index, a, bind);
if (exists && bind)
return 0;
switch (parm->t_action) {
case TCA_TUNNEL_KEY_ACT_RELEASE:
break;
case TCA_TUNNEL_KEY_ACT_SET:
if (!tb[TCA_TUNNEL_KEY_ENC_KEY_ID]) {
ret = -EINVAL;
goto err_out;
}
key_id = key32_to_tunnel_id(nla_get_be32(tb[TCA_TUNNEL_KEY_ENC_KEY_ID]));
flags = TUNNEL_KEY | TUNNEL_CSUM;
if (tb[TCA_TUNNEL_KEY_NO_CSUM] &&
nla_get_u8(tb[TCA_TUNNEL_KEY_NO_CSUM]))
flags &= ~TUNNEL_CSUM;
if (tb[TCA_TUNNEL_KEY_ENC_DST_PORT])
dst_port = nla_get_be16(tb[TCA_TUNNEL_KEY_ENC_DST_PORT]);
if (tb[TCA_TUNNEL_KEY_ENC_IPV4_SRC] &&
tb[TCA_TUNNEL_KEY_ENC_IPV4_DST]) {
__be32 saddr;
__be32 daddr;
saddr = nla_get_in_addr(tb[TCA_TUNNEL_KEY_ENC_IPV4_SRC]);
daddr = nla_get_in_addr(tb[TCA_TUNNEL_KEY_ENC_IPV4_DST]);
metadata = __ip_tun_set_dst(saddr, daddr, 0, 0,
dst_port, flags,
key_id, 0);
} else if (tb[TCA_TUNNEL_KEY_ENC_IPV6_SRC] &&
tb[TCA_TUNNEL_KEY_ENC_IPV6_DST]) {
struct in6_addr saddr;
struct in6_addr daddr;
saddr = nla_get_in6_addr(tb[TCA_TUNNEL_KEY_ENC_IPV6_SRC]);
daddr = nla_get_in6_addr(tb[TCA_TUNNEL_KEY_ENC_IPV6_DST]);
metadata = __ipv6_tun_set_dst(&saddr, &daddr, 0, 0, dst_port,
0, flags,
key_id, 0);
}
if (!metadata) {
ret = -EINVAL;
goto err_out;
}
metadata->u.tun_info.mode |= IP_TUNNEL_INFO_TX;
break;
default:
ret = -EINVAL;
goto err_out;
}
if (!exists) {
ret = tcf_idr_create(tn, parm->index, est, a,
&act_tunnel_key_ops, bind, true);
if (ret)
return ret;
ret = ACT_P_CREATED;
} else {
tcf_idr_release(*a, bind);
if (!ovr)
return -EEXIST;
}
t = to_tunnel_key(*a);
ASSERT_RTNL();
params_new = kzalloc(sizeof(*params_new), GFP_KERNEL);
if (unlikely(!params_new)) {
if (ret == ACT_P_CREATED)
tcf_idr_release(*a, bind);
return -ENOMEM;
}
params_old = rtnl_dereference(t->params);
params_new->action = parm->action;
params_new->tcft_action = parm->t_action;
params_new->tcft_enc_metadata = metadata;
rcu_assign_pointer(t->params, params_new);
if (params_old)
kfree_rcu(params_old, rcu);
if (ret == ACT_P_CREATED)
tcf_idr_insert(tn, *a);
return ret;
err_out:
if (exists)
tcf_idr_release(*a, bind);
return ret;
}
static void tunnel_key_release(struct tc_action *a)
{
struct tcf_tunnel_key *t = to_tunnel_key(a);
struct tcf_tunnel_key_params *params;
params = rcu_dereference_protected(t->params, 1);
if (params) {
if (params->tcft_action == TCA_TUNNEL_KEY_ACT_SET)
dst_release(&params->tcft_enc_metadata->dst);
kfree_rcu(params, rcu);
}
}
static int tunnel_key_dump_addresses(struct sk_buff *skb,
const struct ip_tunnel_info *info)
{
unsigned short family = ip_tunnel_info_af(info);
if (family == AF_INET) {
__be32 saddr = info->key.u.ipv4.src;
__be32 daddr = info->key.u.ipv4.dst;
if (!nla_put_in_addr(skb, TCA_TUNNEL_KEY_ENC_IPV4_SRC, saddr) &&
!nla_put_in_addr(skb, TCA_TUNNEL_KEY_ENC_IPV4_DST, daddr))
return 0;
}
if (family == AF_INET6) {
const struct in6_addr *saddr6 = &info->key.u.ipv6.src;
const struct in6_addr *daddr6 = &info->key.u.ipv6.dst;
if (!nla_put_in6_addr(skb,
TCA_TUNNEL_KEY_ENC_IPV6_SRC, saddr6) &&
!nla_put_in6_addr(skb,
TCA_TUNNEL_KEY_ENC_IPV6_DST, daddr6))
return 0;
}
return -EINVAL;
}
static int tunnel_key_dump(struct sk_buff *skb, struct tc_action *a,
int bind, int ref)
{
unsigned char *b = skb_tail_pointer(skb);
struct tcf_tunnel_key *t = to_tunnel_key(a);
struct tcf_tunnel_key_params *params;
struct tc_tunnel_key opt = {
.index = t->tcf_index,
.refcnt = t->tcf_refcnt - ref,
.bindcnt = t->tcf_bindcnt - bind,
};
struct tcf_t tm;
params = rtnl_dereference(t->params);
opt.t_action = params->tcft_action;
opt.action = params->action;
if (nla_put(skb, TCA_TUNNEL_KEY_PARMS, sizeof(opt), &opt))
goto nla_put_failure;
if (params->tcft_action == TCA_TUNNEL_KEY_ACT_SET) {
struct ip_tunnel_key *key =
&params->tcft_enc_metadata->u.tun_info.key;
__be32 key_id = tunnel_id_to_key32(key->tun_id);
if (nla_put_be32(skb, TCA_TUNNEL_KEY_ENC_KEY_ID, key_id) ||
tunnel_key_dump_addresses(skb,
&params->tcft_enc_metadata->u.tun_info) ||
nla_put_be16(skb, TCA_TUNNEL_KEY_ENC_DST_PORT, key->tp_dst) ||
nla_put_u8(skb, TCA_TUNNEL_KEY_NO_CSUM,
!(key->tun_flags & TUNNEL_CSUM)))
goto nla_put_failure;
}
tcf_tm_dump(&tm, &t->tcf_tm);
if (nla_put_64bit(skb, TCA_TUNNEL_KEY_TM, sizeof(tm),
&tm, TCA_TUNNEL_KEY_PAD))
goto nla_put_failure;
return skb->len;
nla_put_failure:
nlmsg_trim(skb, b);
return -1;
}
static int tunnel_key_walker(struct net *net, struct sk_buff *skb,
struct netlink_callback *cb, int type,
const struct tc_action_ops *ops)
{
struct tc_action_net *tn = net_generic(net, tunnel_key_net_id);
return tcf_generic_walker(tn, skb, cb, type, ops);
}
static int tunnel_key_search(struct net *net, struct tc_action **a, u32 index)
{
struct tc_action_net *tn = net_generic(net, tunnel_key_net_id);
return tcf_idr_search(tn, a, index);
}
static struct tc_action_ops act_tunnel_key_ops = {
.kind = "tunnel_key",
.type = TCA_ACT_TUNNEL_KEY,
.owner = THIS_MODULE,
.act = tunnel_key_act,
.dump = tunnel_key_dump,
.init = tunnel_key_init,
.cleanup = tunnel_key_release,
.walk = tunnel_key_walker,
.lookup = tunnel_key_search,
.size = sizeof(struct tcf_tunnel_key),
};
static __net_init int tunnel_key_init_net(struct net *net)
{
struct tc_action_net *tn = net_generic(net, tunnel_key_net_id);
return tc_action_net_init(tn, &act_tunnel_key_ops);
}
static void __net_exit tunnel_key_exit_net(struct list_head *net_list)
{
tc_action_net_exit(net_list, tunnel_key_net_id);
}
static struct pernet_operations tunnel_key_net_ops = {
.init = tunnel_key_init_net,
.exit_batch = tunnel_key_exit_net,
.id = &tunnel_key_net_id,
.size = sizeof(struct tc_action_net),
};
static int __init tunnel_key_init_module(void)
{
return tcf_register_action(&act_tunnel_key_ops, &tunnel_key_net_ops);
}
static void __exit tunnel_key_cleanup_module(void)
{
tcf_unregister_action(&act_tunnel_key_ops, &tunnel_key_net_ops);
}
module_init(tunnel_key_init_module);
module_exit(tunnel_key_cleanup_module);
MODULE_AUTHOR("Amir Vadai <amir@vadai.me>");
MODULE_DESCRIPTION("ip tunnel manipulation actions");
MODULE_LICENSE("GPL v2");