linux/include/net/tc_act/tc_tunnel_key.h
Leon Romanovsky d086a1c65a net: sched: Fix suspicious RCU usage while accessing tcf_tunnel_info
The access of tcf_tunnel_info() produces the following splat, so fix it
by dereferencing the tcf_tunnel_key_params pointer with marker that
internal tcfa_liock is held.

 =============================
 WARNING: suspicious RCU usage
 5.9.0+ #1 Not tainted
 -----------------------------
 include/net/tc_act/tc_tunnel_key.h:59 suspicious rcu_dereference_protected() usage!
 other info that might help us debug this:

 rcu_scheduler_active = 2, debug_locks = 1
 1 lock held by tc/34839:
  #0: ffff88828572c2a0 (&p->tcfa_lock){+...}-{2:2}, at: tc_setup_flow_action+0xb3/0x48b5
 stack backtrace:
 CPU: 1 PID: 34839 Comm: tc Not tainted 5.9.0+ #1
 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.org 04/01/2014
 Call Trace:
  dump_stack+0x9a/0xd0
  tc_setup_flow_action+0x14cb/0x48b5
  fl_hw_replace_filter+0x347/0x690 [cls_flower]
  fl_change+0x2bad/0x4875 [cls_flower]
  tc_new_tfilter+0xf6f/0x1ba0
  rtnetlink_rcv_msg+0x5f2/0x870
  netlink_rcv_skb+0x124/0x350
  netlink_unicast+0x433/0x700
  netlink_sendmsg+0x6f1/0xbd0
  sock_sendmsg+0xb0/0xe0
  ____sys_sendmsg+0x4fa/0x6d0
  ___sys_sendmsg+0x12e/0x1b0
  __sys_sendmsg+0xa4/0x120
  do_syscall_64+0x2d/0x40
  entry_SYSCALL_64_after_hwframe+0x44/0xa9
 RIP: 0033:0x7f1f8cd4fe57
 Code: 0c 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 2e 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 89 54 24 1c 48 89 74 24 10
 RSP: 002b:00007ffdc1e193b8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f1f8cd4fe57
 RDX: 0000000000000000 RSI: 00007ffdc1e19420 RDI: 0000000000000003
 RBP: 000000005f85aafa R08: 0000000000000001 R09: 00007ffdc1e1936c
 R10: 000000000040522d R11: 0000000000000246 R12: 0000000000000001
 R13: 0000000000000000 R14: 00007ffdc1e1d6f0 R15: 0000000000482420

Fixes: 3ebaf6da07 ("net: sched: Do not assume RTNL is held in tunnel key action helpers")
Fixes: 7a47281439 ("net: sched: lock action when translating it to flow_action infra")
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Acked-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-10-15 09:10:11 -07:00

87 lines
2.1 KiB
C

/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
* Copyright (c) 2016, Amir Vadai <amir@vadai.me>
* Copyright (c) 2016, Mellanox Technologies. All rights reserved.
*/
#ifndef __NET_TC_TUNNEL_KEY_H
#define __NET_TC_TUNNEL_KEY_H
#include <net/act_api.h>
#include <linux/tc_act/tc_tunnel_key.h>
#include <net/dst_metadata.h>
struct tcf_tunnel_key_params {
struct rcu_head rcu;
int tcft_action;
struct metadata_dst *tcft_enc_metadata;
};
struct tcf_tunnel_key {
struct tc_action common;
struct tcf_tunnel_key_params __rcu *params;
};
#define to_tunnel_key(a) ((struct tcf_tunnel_key *)a)
static inline bool is_tcf_tunnel_set(const struct tc_action *a)
{
#ifdef CONFIG_NET_CLS_ACT
struct tcf_tunnel_key *t = to_tunnel_key(a);
struct tcf_tunnel_key_params *params;
params = rcu_dereference_protected(t->params,
lockdep_is_held(&a->tcfa_lock));
if (a->ops && a->ops->id == TCA_ID_TUNNEL_KEY)
return params->tcft_action == TCA_TUNNEL_KEY_ACT_SET;
#endif
return false;
}
static inline bool is_tcf_tunnel_release(const struct tc_action *a)
{
#ifdef CONFIG_NET_CLS_ACT
struct tcf_tunnel_key *t = to_tunnel_key(a);
struct tcf_tunnel_key_params *params;
params = rcu_dereference_protected(t->params,
lockdep_is_held(&a->tcfa_lock));
if (a->ops && a->ops->id == TCA_ID_TUNNEL_KEY)
return params->tcft_action == TCA_TUNNEL_KEY_ACT_RELEASE;
#endif
return false;
}
static inline struct ip_tunnel_info *tcf_tunnel_info(const struct tc_action *a)
{
#ifdef CONFIG_NET_CLS_ACT
struct tcf_tunnel_key *t = to_tunnel_key(a);
struct tcf_tunnel_key_params *params;
params = rcu_dereference_protected(t->params,
lockdep_is_held(&a->tcfa_lock));
return &params->tcft_enc_metadata->u.tun_info;
#else
return NULL;
#endif
}
static inline struct ip_tunnel_info *
tcf_tunnel_info_copy(const struct tc_action *a)
{
#ifdef CONFIG_NET_CLS_ACT
struct ip_tunnel_info *tun = tcf_tunnel_info(a);
if (tun) {
size_t tun_size = sizeof(*tun) + tun->options_len;
struct ip_tunnel_info *tun_copy = kmemdup(tun, tun_size,
GFP_ATOMIC);
return tun_copy;
}
#endif
return NULL;
}
#endif /* __NET_TC_TUNNEL_KEY_H */