diff options
author | 2019-08-27 21:49:38 +0300 | |
---|---|---|
committer | 2019-08-28 15:53:51 -0700 | |
commit | dbf47a2a094edf58983265e323ca4bdcdb58b5ee (patch) | |
tree | 4d67881165f57063cadc0456b7c7e5c8be0b5090 /net/sched | |
parent | ibmvnic: Do not process reset during or after device removal (diff) | |
download | linux-dbf47a2a094edf58983265e323ca4bdcdb58b5ee.tar.gz linux-dbf47a2a094edf58983265e323ca4bdcdb58b5ee.tar.bz2 linux-dbf47a2a094edf58983265e323ca4bdcdb58b5ee.zip |
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: 5c5670fae430 ("net/sched: Introduce sample tc action")
Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/sched')
-rw-r--r-- | net/sched/act_sample.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/net/sched/act_sample.c b/net/sched/act_sample.c index 7eff363f9f03..10229124a992 100644 --- a/net/sched/act_sample.c +++ b/net/sched/act_sample.c @@ -102,13 +102,17 @@ static int tcf_sample_init(struct net *net, struct nlattr *nla, goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch); s->rate = rate; s->psample_group_num = psample_group_num; - RCU_INIT_POINTER(s->psample_group, psample_group); + rcu_swap_protected(s->psample_group, psample_group, + lockdep_is_held(&s->tcf_lock)); if (tb[TCA_SAMPLE_TRUNC_SIZE]) { s->truncate = true; s->trunc_size = nla_get_u32(tb[TCA_SAMPLE_TRUNC_SIZE]); } spin_unlock_bh(&s->tcf_lock); + + if (psample_group) + psample_group_put(psample_group); if (goto_ch) tcf_chain_put_by_act(goto_ch); |