path: root/net/sched/act_bpf.c
diff options
authorDmytro Linkin <dmitrolin@mellanox.com>2019-08-01 13:02:51 +0000
committerDavid S. Miller <davem@davemloft.net>2019-08-05 10:59:14 -0700
commit7be8ef2cdbfe41a2e524b7c6cc3f8e6cfaa906e4 (patch)
tree42b36459934917001e8ed83595d238924120b3c9 /net/sched/act_bpf.c
parentnet: dsa: mv88e6xxx: drop adjust_link to enabled phylink (diff)
net: sched: use temporary variable for actions indexes
Currently init call of all actions (except ipt) init their 'parm' structure as a direct pointer to nla data in skb. This leads to race condition when some of the filter actions were initialized successfully (and were assigned with idr action index that was written directly into nla data), but then were deleted and retried (due to following action module missing or classifier-initiated retry), in which case action init code tries to insert action to idr with index that was assigned on previous iteration. During retry the index can be reused by another action that was inserted concurrently, which causes unintended action sharing between filters. To fix described race condition, save action idr index to temporary stack-allocated variable instead on nla data. Fixes: 0190c1d452a9 ("net: sched: atomically check-allocate action") Signed-off-by: Dmytro Linkin <dmitrolin@mellanox.com> Signed-off-by: Vlad Buslov <vladbu@mellanox.com> Acked-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to '')
1 files changed, 5 insertions, 4 deletions
diff --git a/net/sched/act_bpf.c b/net/sched/act_bpf.c
index 8126b26f125e..fd1f7e799e23 100644
--- a/net/sched/act_bpf.c
+++ b/net/sched/act_bpf.c
@@ -285,6 +285,7 @@ static int tcf_bpf_init(struct net *net, struct nlattr *nla,
struct tcf_bpf *prog;
bool is_bpf, is_ebpf;
int ret, res = 0;
+ u32 index;
if (!nla)
return -EINVAL;
@@ -298,13 +299,13 @@ static int tcf_bpf_init(struct net *net, struct nlattr *nla,
return -EINVAL;
parm = nla_data(tb[TCA_ACT_BPF_PARMS]);
- ret = tcf_idr_check_alloc(tn, &parm->index, act, bind);
+ index = parm->index;
+ ret = tcf_idr_check_alloc(tn, &index, act, bind);
if (!ret) {
- ret = tcf_idr_create(tn, parm->index, est, act,
+ ret = tcf_idr_create(tn, index, est, act,
&act_bpf_ops, bind, true);
if (ret < 0) {
- tcf_idr_cleanup(tn, parm->index);
+ tcf_idr_cleanup(tn, index);
return ret;