From dbf47a2a094edf58983265e323ca4bdcdb58b5ee Mon Sep 17 00:00:00 2001 From: Vlad Buslov Date: Tue, 27 Aug 2019 21:49:38 +0300 Subject: 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 Signed-off-by: David S. Miller --- net/psample/psample.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'net/psample') diff --git a/net/psample/psample.c b/net/psample/psample.c index 841f198ea1a8..66e4b61a350d 100644 --- a/net/psample/psample.c +++ b/net/psample/psample.c @@ -154,7 +154,7 @@ static void psample_group_destroy(struct psample_group *group) { psample_group_notify(group, PSAMPLE_CMD_DEL_GROUP); list_del(&group->list); - kfree(group); + kfree_rcu(group, rcu); } static struct psample_group * -- cgit v1.2.3