linux_dsm_epyc7002/net/sched/act_vlan.c
Davide Caratti 7e0c8892df net/sched: act_vlan: validate the control action inside init()
the following script:

 # tc qdisc add dev crash0 clsact
 # tc filter add dev crash0 egress matchall \
 > action vlan pop pass index 90
 # tc actions replace action vlan \
 > pop goto chain 42 index 90 cookie c1a0c1a0
 # tc actions show action vlan

had the following output:

 Error: Failed to init TC action chain.
 We have an error talking to the kernel
 total acts 1

         action order 0: vlan  pop goto chain 42
          index 90 ref 2 bind 1
         cookie c1a0c1a0

Then, the first packet transmitted by crash0 made the kernel crash:

 BUG: unable to handle kernel NULL pointer dereference at 0000000000000000
 #PF error: [normal kernel read fault]
 PGD 800000007974f067 P4D 800000007974f067 PUD 79638067 PMD 0
 Oops: 0000 [#1] SMP PTI
 CPU: 3 PID: 0 Comm: swapper/3 Not tainted 5.0.0-rc4.gotochain_crash+ #536
 Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011
 RIP: 0010:tcf_action_exec+0xb8/0x100
 Code: 00 00 00 20 74 1d 83 f8 03 75 09 49 83 c4 08 4d 39 ec 75 bc 48 83 c4 10 5b 5d 41 5c 41 5d 41 5e 41 5f c3 49 8b 97 a8 00 00 00 <48> 8b 12 48 89 55 00 48 83 c4 10 5b 5d 41 5c 41 5d 41 5e 41 5f c3
 RSP: 0018:ffff982dfdb83be0 EFLAGS: 00010246
 RAX: 000000002000002a RBX: ffff982dfc55db00 RCX: 0000000000000000
 RDX: 0000000000000000 RSI: ffff982df97099c0 RDI: ffff982dfc55db00
 RBP: ffff982dfdb83c80 R08: ffff982df983fec8 R09: 0000000000000000
 R10: 0000000000000000 R11: 0000000000000000 R12: ffff982df5aacd00
 R13: ffff982df5aacd08 R14: 0000000000000001 R15: ffff982df97099c0
 FS:  0000000000000000(0000) GS:ffff982dfdb80000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000000000000000 CR3: 00000000796d0005 CR4: 00000000001606e0
 Call Trace:
  <IRQ>
  tcf_classify+0x58/0x120
  __dev_queue_xmit+0x40a/0x890
  ? ip6_finish_output2+0x369/0x590
  ip6_finish_output2+0x369/0x590
  ? ip6_output+0x68/0x110
  ip6_output+0x68/0x110
  ? nf_hook.constprop.35+0x79/0xc0
  mld_sendpack+0x16f/0x220
  mld_ifc_timer_expire+0x195/0x2c0
  ? igmp6_timer_handler+0x70/0x70
  call_timer_fn+0x2b/0x130
  run_timer_softirq+0x3e8/0x440
  ? enqueue_hrtimer+0x39/0x90
  __do_softirq+0xe3/0x2f5
  irq_exit+0xf0/0x100
  smp_apic_timer_interrupt+0x6c/0x130
  apic_timer_interrupt+0xf/0x20
  </IRQ>
 RIP: 0010:native_safe_halt+0x2/0x10
 Code: 7b ff ff ff 7f f3 c3 65 48 8b 04 25 00 5c 01 00 f0 80 48 02 20 48 8b 00 a8 08 74 8b eb c1 90 90 90 90 90 90 90 90 90 90 fb f4 <c3> 0f 1f 00 66 2e 0f 1f 84 00 00 00 00 00 f4 c3 90 90 90 90 90 90
 RSP: 0018:ffffa4714038feb8 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
 RAX: ffffffff840184f0 RBX: 0000000000000003 RCX: 0000000000000000
 RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000001e57d3f387
 RBP: 0000000000000003 R08: 001125d9ca39e1eb R09: 0000000000000000
 R10: 000000000000027d R11: 000000000009f400 R12: 0000000000000000
 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
  ? __sched_text_end+0x1/0x1
  default_idle+0x1c/0x140
  do_idle+0x1c4/0x280
  cpu_startup_entry+0x19/0x20
  start_secondary+0x1a7/0x200
  secondary_startup_64+0xa4/0xb0
 Modules linked in: act_vlan veth ip6table_filter ip6_tables iptable_filter binfmt_misc ext4 snd_hda_codec_generic mbcache crct10dif_pclmul jbd2 snd_hda_intel crc32_pclmul snd_hda_codec ghash_clmulni_intel snd_hwdep snd_hda_core snd_seq snd_seq_device snd_pcm aesni_intel crypto_simd cryptd glue_helper joydev snd_timer virtio_balloon snd pcspkr soundcore i2c_piix4 nfsd auth_rpcgss nfs_acl lockd grace sunrpc ip_tables xfs ata_generic pata_acpi qxl drm_kms_helper syscopyarea sysfillrect sysimgblt virtio_net fb_sys_fops virtio_blk ttm net_failover virtio_console failover ata_piix drm libata crc32c_intel virtio_pci serio_raw virtio_ring virtio floppy dm_mirror dm_region_hash dm_log dm_mod
 CR2: 0000000000000000

Validating the control action within tcf_vlan_init() proved to fix the
above issue. A TDC selftest is added to verify the correct behavior.

Fixes: db50514f9a ("net: sched: add termination action to allow goto chain")
Fixes: 97763dc0f4 ("net_sched: reject unknown tcfa_action values")
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-03-21 13:26:42 -07:00

360 lines
8.6 KiB
C

/*
* Copyright (c) 2014 Jiri Pirko <jiri@resnulli.us>
*
* 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 <linux/if_vlan.h>
#include <net/netlink.h>
#include <net/pkt_sched.h>
#include <net/pkt_cls.h>
#include <linux/tc_act/tc_vlan.h>
#include <net/tc_act/tc_vlan.h>
static unsigned int vlan_net_id;
static struct tc_action_ops act_vlan_ops;
static int tcf_vlan_act(struct sk_buff *skb, const struct tc_action *a,
struct tcf_result *res)
{
struct tcf_vlan *v = to_vlan(a);
struct tcf_vlan_params *p;
int action;
int err;
u16 tci;
tcf_lastuse_update(&v->tcf_tm);
bstats_cpu_update(this_cpu_ptr(v->common.cpu_bstats), skb);
/* Ensure 'data' points at mac_header prior calling vlan manipulating
* functions.
*/
if (skb_at_tc_ingress(skb))
skb_push_rcsum(skb, skb->mac_len);
action = READ_ONCE(v->tcf_action);
p = rcu_dereference_bh(v->vlan_p);
switch (p->tcfv_action) {
case TCA_VLAN_ACT_POP:
err = skb_vlan_pop(skb);
if (err)
goto drop;
break;
case TCA_VLAN_ACT_PUSH:
err = skb_vlan_push(skb, p->tcfv_push_proto, p->tcfv_push_vid |
(p->tcfv_push_prio << VLAN_PRIO_SHIFT));
if (err)
goto drop;
break;
case TCA_VLAN_ACT_MODIFY:
/* No-op if no vlan tag (either hw-accel or in-payload) */
if (!skb_vlan_tagged(skb))
goto out;
/* extract existing tag (and guarantee no hw-accel tag) */
if (skb_vlan_tag_present(skb)) {
tci = skb_vlan_tag_get(skb);
__vlan_hwaccel_clear_tag(skb);
} else {
/* in-payload vlan tag, pop it */
err = __skb_vlan_pop(skb, &tci);
if (err)
goto drop;
}
/* replace the vid */
tci = (tci & ~VLAN_VID_MASK) | p->tcfv_push_vid;
/* replace prio bits, if tcfv_push_prio specified */
if (p->tcfv_push_prio) {
tci &= ~VLAN_PRIO_MASK;
tci |= p->tcfv_push_prio << VLAN_PRIO_SHIFT;
}
/* put updated tci as hwaccel tag */
__vlan_hwaccel_put_tag(skb, p->tcfv_push_proto, tci);
break;
default:
BUG();
}
out:
if (skb_at_tc_ingress(skb))
skb_pull_rcsum(skb, skb->mac_len);
return action;
drop:
qstats_drop_inc(this_cpu_ptr(v->common.cpu_qstats));
return TC_ACT_SHOT;
}
static const struct nla_policy vlan_policy[TCA_VLAN_MAX + 1] = {
[TCA_VLAN_PARMS] = { .len = sizeof(struct tc_vlan) },
[TCA_VLAN_PUSH_VLAN_ID] = { .type = NLA_U16 },
[TCA_VLAN_PUSH_VLAN_PROTOCOL] = { .type = NLA_U16 },
[TCA_VLAN_PUSH_VLAN_PRIORITY] = { .type = NLA_U8 },
};
static int tcf_vlan_init(struct net *net, struct nlattr *nla,
struct nlattr *est, struct tc_action **a,
int ovr, int bind, bool rtnl_held,
struct tcf_proto *tp, struct netlink_ext_ack *extack)
{
struct tc_action_net *tn = net_generic(net, vlan_net_id);
struct nlattr *tb[TCA_VLAN_MAX + 1];
struct tcf_chain *goto_ch = NULL;
struct tcf_vlan_params *p;
struct tc_vlan *parm;
struct tcf_vlan *v;
int action;
u16 push_vid = 0;
__be16 push_proto = 0;
u8 push_prio = 0;
bool exists = false;
int ret = 0, err;
if (!nla)
return -EINVAL;
err = nla_parse_nested(tb, TCA_VLAN_MAX, nla, vlan_policy, NULL);
if (err < 0)
return err;
if (!tb[TCA_VLAN_PARMS])
return -EINVAL;
parm = nla_data(tb[TCA_VLAN_PARMS]);
err = tcf_idr_check_alloc(tn, &parm->index, a, bind);
if (err < 0)
return err;
exists = err;
if (exists && bind)
return 0;
switch (parm->v_action) {
case TCA_VLAN_ACT_POP:
break;
case TCA_VLAN_ACT_PUSH:
case TCA_VLAN_ACT_MODIFY:
if (!tb[TCA_VLAN_PUSH_VLAN_ID]) {
if (exists)
tcf_idr_release(*a, bind);
else
tcf_idr_cleanup(tn, parm->index);
return -EINVAL;
}
push_vid = nla_get_u16(tb[TCA_VLAN_PUSH_VLAN_ID]);
if (push_vid >= VLAN_VID_MASK) {
if (exists)
tcf_idr_release(*a, bind);
else
tcf_idr_cleanup(tn, parm->index);
return -ERANGE;
}
if (tb[TCA_VLAN_PUSH_VLAN_PROTOCOL]) {
push_proto = nla_get_be16(tb[TCA_VLAN_PUSH_VLAN_PROTOCOL]);
switch (push_proto) {
case htons(ETH_P_8021Q):
case htons(ETH_P_8021AD):
break;
default:
if (exists)
tcf_idr_release(*a, bind);
else
tcf_idr_cleanup(tn, parm->index);
return -EPROTONOSUPPORT;
}
} else {
push_proto = htons(ETH_P_8021Q);
}
if (tb[TCA_VLAN_PUSH_VLAN_PRIORITY])
push_prio = nla_get_u8(tb[TCA_VLAN_PUSH_VLAN_PRIORITY]);
break;
default:
if (exists)
tcf_idr_release(*a, bind);
else
tcf_idr_cleanup(tn, parm->index);
return -EINVAL;
}
action = parm->v_action;
if (!exists) {
ret = tcf_idr_create(tn, parm->index, est, a,
&act_vlan_ops, bind, true);
if (ret) {
tcf_idr_cleanup(tn, parm->index);
return ret;
}
ret = ACT_P_CREATED;
} else if (!ovr) {
tcf_idr_release(*a, bind);
return -EEXIST;
}
err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack);
if (err < 0)
goto release_idr;
v = to_vlan(*a);
p = kzalloc(sizeof(*p), GFP_KERNEL);
if (!p) {
err = -ENOMEM;
goto put_chain;
}
p->tcfv_action = action;
p->tcfv_push_vid = push_vid;
p->tcfv_push_prio = push_prio;
p->tcfv_push_proto = push_proto;
spin_lock_bh(&v->tcf_lock);
goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
rcu_swap_protected(v->vlan_p, p, lockdep_is_held(&v->tcf_lock));
spin_unlock_bh(&v->tcf_lock);
if (goto_ch)
tcf_chain_put_by_act(goto_ch);
if (p)
kfree_rcu(p, rcu);
if (ret == ACT_P_CREATED)
tcf_idr_insert(tn, *a);
return ret;
put_chain:
if (goto_ch)
tcf_chain_put_by_act(goto_ch);
release_idr:
tcf_idr_release(*a, bind);
return err;
}
static void tcf_vlan_cleanup(struct tc_action *a)
{
struct tcf_vlan *v = to_vlan(a);
struct tcf_vlan_params *p;
p = rcu_dereference_protected(v->vlan_p, 1);
if (p)
kfree_rcu(p, rcu);
}
static int tcf_vlan_dump(struct sk_buff *skb, struct tc_action *a,
int bind, int ref)
{
unsigned char *b = skb_tail_pointer(skb);
struct tcf_vlan *v = to_vlan(a);
struct tcf_vlan_params *p;
struct tc_vlan opt = {
.index = v->tcf_index,
.refcnt = refcount_read(&v->tcf_refcnt) - ref,
.bindcnt = atomic_read(&v->tcf_bindcnt) - bind,
};
struct tcf_t t;
spin_lock_bh(&v->tcf_lock);
opt.action = v->tcf_action;
p = rcu_dereference_protected(v->vlan_p, lockdep_is_held(&v->tcf_lock));
opt.v_action = p->tcfv_action;
if (nla_put(skb, TCA_VLAN_PARMS, sizeof(opt), &opt))
goto nla_put_failure;
if ((p->tcfv_action == TCA_VLAN_ACT_PUSH ||
p->tcfv_action == TCA_VLAN_ACT_MODIFY) &&
(nla_put_u16(skb, TCA_VLAN_PUSH_VLAN_ID, p->tcfv_push_vid) ||
nla_put_be16(skb, TCA_VLAN_PUSH_VLAN_PROTOCOL,
p->tcfv_push_proto) ||
(nla_put_u8(skb, TCA_VLAN_PUSH_VLAN_PRIORITY,
p->tcfv_push_prio))))
goto nla_put_failure;
tcf_tm_dump(&t, &v->tcf_tm);
if (nla_put_64bit(skb, TCA_VLAN_TM, sizeof(t), &t, TCA_VLAN_PAD))
goto nla_put_failure;
spin_unlock_bh(&v->tcf_lock);
return skb->len;
nla_put_failure:
spin_unlock_bh(&v->tcf_lock);
nlmsg_trim(skb, b);
return -1;
}
static int tcf_vlan_walker(struct net *net, struct sk_buff *skb,
struct netlink_callback *cb, int type,
const struct tc_action_ops *ops,
struct netlink_ext_ack *extack)
{
struct tc_action_net *tn = net_generic(net, vlan_net_id);
return tcf_generic_walker(tn, skb, cb, type, ops, extack);
}
static int tcf_vlan_search(struct net *net, struct tc_action **a, u32 index)
{
struct tc_action_net *tn = net_generic(net, vlan_net_id);
return tcf_idr_search(tn, a, index);
}
static struct tc_action_ops act_vlan_ops = {
.kind = "vlan",
.id = TCA_ID_VLAN,
.owner = THIS_MODULE,
.act = tcf_vlan_act,
.dump = tcf_vlan_dump,
.init = tcf_vlan_init,
.cleanup = tcf_vlan_cleanup,
.walk = tcf_vlan_walker,
.lookup = tcf_vlan_search,
.size = sizeof(struct tcf_vlan),
};
static __net_init int vlan_init_net(struct net *net)
{
struct tc_action_net *tn = net_generic(net, vlan_net_id);
return tc_action_net_init(tn, &act_vlan_ops);
}
static void __net_exit vlan_exit_net(struct list_head *net_list)
{
tc_action_net_exit(net_list, vlan_net_id);
}
static struct pernet_operations vlan_net_ops = {
.init = vlan_init_net,
.exit_batch = vlan_exit_net,
.id = &vlan_net_id,
.size = sizeof(struct tc_action_net),
};
static int __init vlan_init_module(void)
{
return tcf_register_action(&act_vlan_ops, &vlan_net_ops);
}
static void __exit vlan_cleanup_module(void)
{
tcf_unregister_action(&act_vlan_ops, &vlan_net_ops);
}
module_init(vlan_init_module);
module_exit(vlan_cleanup_module);
MODULE_AUTHOR("Jiri Pirko <jiri@resnulli.us>");
MODULE_DESCRIPTION("vlan manipulation actions");
MODULE_LICENSE("GPL v2");