linux-stable/include/net/psample.h
Vlad Buslov dbf47a2a09 net: sched: act_sample: fix psample group handling on overwrite
Action sample doesn't properly handle psample_group pointer in overwrite
case. Following issues need to be fixed:

- In tcf_sample_init() function RCU_INIT_POINTER() is used to set
  s->psample_group, even though we neither setting the pointer to NULL, nor
  preventing concurrent readers from accessing the pointer in some way.
  Use rcu_swap_protected() instead to safely reset the pointer.

- Old value of s->psample_group is not released or deallocated in any way,
  which results resource leak. Use psample_group_put() on non-NULL value
  obtained with rcu_swap_protected().

- The function psample_group_put() that released reference to struct
  psample_group pointed by rcu-pointer s->psample_group doesn't respect rcu
  grace period when deallocating it. Extend struct psample_group with rcu
  head and use kfree_rcu when freeing it.

Fixes: 5c5670fae4 ("net/sched: Introduce sample tc action")
Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-08-28 15:53:51 -07:00

37 lines
817 B
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __NET_PSAMPLE_H
#define __NET_PSAMPLE_H
#include <uapi/linux/psample.h>
#include <linux/list.h>
struct psample_group {
struct list_head list;
struct net *net;
u32 group_num;
u32 refcount;
u32 seq;
struct rcu_head rcu;
};
struct psample_group *psample_group_get(struct net *net, u32 group_num);
void psample_group_put(struct psample_group *group);
#if IS_ENABLED(CONFIG_PSAMPLE)
void psample_sample_packet(struct psample_group *group, struct sk_buff *skb,
u32 trunc_size, int in_ifindex, int out_ifindex,
u32 sample_rate);
#else
static inline void psample_sample_packet(struct psample_group *group,
struct sk_buff *skb, u32 trunc_size,
int in_ifindex, int out_ifindex,
u32 sample_rate)
{
}
#endif
#endif /* __NET_PSAMPLE_H */