From: Vlad Buslov <vladbu@mellanox.com>
Date: Thu, 5 Jul 2018 17:24:30 +0300
Subject: net: sched: don't release reference on action overwrite
Patch-mainline: v4.19-rc1
Git-commit: 4e8ddd7f1758ca4ddd0c1f7cf3e66fce736241d2
References: bsc#1109837
Return from action init function with reference to action taken,
even when overwriting existing action.
Action init API initializes its fourth argument (pointer to pointer to tc
action) to either existing action with same index or newly created action.
In case of existing index(and bind argument is zero), init function returns
without incrementing action reference counter. Caller of action init then
proceeds working with action, without actually holding reference to it.
This means that action could be deleted concurrently.
Change action init behavior to always take reference to action before
returning successfully, in order to protect from concurrent deletion.
Reviewed-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
net/sched/act_api.c | 2 --
net/sched/act_bpf.c | 8 ++++----
net/sched/act_connmark.c | 5 +++--
net/sched/act_csum.c | 8 ++++----
net/sched/act_gact.c | 5 +++--
net/sched/act_ife.c | 10 +++++-----
net/sched/act_ipt.c | 5 +++--
net/sched/act_mirred.c | 5 ++---
net/sched/act_nat.c | 5 +++--
net/sched/act_pedit.c | 2 +-
net/sched/act_police.c | 8 +++-----
net/sched/act_sample.c | 8 +++-----
net/sched/act_simple.c | 5 +++--
net/sched/act_skbedit.c | 5 +++--
net/sched/act_skbmod.c | 8 +++-----
net/sched/act_tunnel_key.c | 11 ++++-------
net/sched/act_vlan.c | 8 +++-----
17 files changed, 50 insertions(+), 58 deletions(-)
--- a/net/sched/act_api.c
+++ b/net/sched/act_api.c
@@ -871,8 +871,6 @@ int tcf_action_init(struct net *net, str
}
act->order = i;
sz += tcf_action_fill_size(act);
- if (ovr)
- refcount_inc(&act->tcfa_refcnt);
list_add_tail(&act->list, actions);
}
--- a/net/sched/act_bpf.c
+++ b/net/sched/act_bpf.c
@@ -311,9 +311,10 @@ static int tcf_bpf_init(struct net *net,
if (bind)
return 0;
- tcf_idr_release(*act, bind);
- if (!replace)
+ if (!replace) {
+ tcf_idr_release(*act, bind);
return -EEXIST;
+ }
}
is_bpf = tb[TCA_ACT_BPF_OPS_LEN] && tb[TCA_ACT_BPF_OPS];
@@ -356,8 +357,7 @@ static int tcf_bpf_init(struct net *net,
return res;
out:
- if (res == ACT_P_CREATED)
- tcf_idr_release(*act, bind);
+ tcf_idr_release(*act, bind);
return ret;
}
--- a/net/sched/act_connmark.c
+++ b/net/sched/act_connmark.c
@@ -135,9 +135,10 @@ static int tcf_connmark_init(struct net
ci = to_connmark(*a);
if (bind)
return 0;
- tcf_idr_release(*a, bind);
- if (!ovr)
+ if (!ovr) {
+ tcf_idr_release(*a, bind);
return -EEXIST;
+ }
/* replacing action and zone */
ci->tcf_action = parm->action;
ci->zone = parm->zone;
--- a/net/sched/act_csum.c
+++ b/net/sched/act_csum.c
@@ -76,9 +76,10 @@ static int tcf_csum_init(struct net *net
} else {
if (bind)/* dont override defaults */
return 0;
- tcf_idr_release(*a, bind);
- if (!ovr)
+ if (!ovr) {
+ tcf_idr_release(*a, bind);
return -EEXIST;
+ }
}
p = to_tcf_csum(*a);
@@ -86,8 +87,7 @@ static int tcf_csum_init(struct net *net
params_new = kzalloc(sizeof(*params_new), GFP_KERNEL);
if (unlikely(!params_new)) {
- if (ret == ACT_P_CREATED)
- tcf_idr_release(*a, bind);
+ tcf_idr_release(*a, bind);
return -ENOMEM;
}
params_old = rtnl_dereference(p->params);
--- a/net/sched/act_gact.c
+++ b/net/sched/act_gact.c
@@ -100,9 +100,10 @@ static int tcf_gact_init(struct net *net
} else {
if (bind)/* dont override defaults */
return 0;
- tcf_idr_release(*a, bind);
- if (!ovr)
+ if (!ovr) {
+ tcf_idr_release(*a, bind);
return -EEXIST;
+ }
}
gact = to_gact(*a);
--- a/net/sched/act_ife.c
+++ b/net/sched/act_ife.c
@@ -498,12 +498,10 @@ static int tcf_ife_init(struct net *net,
return ret;
}
ret = ACT_P_CREATED;
- } else {
+ } else if (!ovr) {
tcf_idr_release(*a, bind);
- if (!ovr) {
- kfree(p);
- return -EEXIST;
- }
+ kfree(p);
+ return -EEXIST;
}
ife = to_ife(*a);
@@ -548,6 +546,8 @@ metadata_parse_err:
if (exists)
spin_unlock_bh(&ife->tcf_lock);
+ tcf_idr_release(*a, bind);
+
kfree(p);
return err;
}
--- a/net/sched/act_ipt.c
+++ b/net/sched/act_ipt.c
@@ -145,10 +145,11 @@ static int __tcf_ipt_init(struct net *ne
} else {
if (bind)/* dont override defaults */
return 0;
- tcf_idr_release(*a, bind);
- if (!ovr)
+ if (!ovr) {
+ tcf_idr_release(*a, bind);
return -EEXIST;
+ }
}
hook = nla_get_u32(tb[TCA_IPT_HOOK]);
--- a/net/sched/act_mirred.c
+++ b/net/sched/act_mirred.c
@@ -132,10 +132,9 @@ static int tcf_mirred_init(struct net *n
if (ret)
return ret;
ret = ACT_P_CREATED;
- } else {
+ } else if (!ovr) {
tcf_idr_release(*a, bind);
- if (!ovr)
- return -EEXIST;
+ return -EEXIST;
}
m = to_mirred(*a);
--- a/net/sched/act_nat.c
+++ b/net/sched/act_nat.c
@@ -66,9 +66,10 @@ static int tcf_nat_init(struct net *net,
} else {
if (bind)
return 0;
- tcf_idr_release(*a, bind);
- if (!ovr)
+ if (!ovr) {
+ tcf_idr_release(*a, bind);
return -EEXIST;
+ }
}
p = to_tcf_nat(*a);
--- a/net/sched/act_pedit.c
+++ b/net/sched/act_pedit.c
@@ -194,8 +194,8 @@ static int tcf_pedit_init(struct net *ne
} else {
if (bind)
goto out_free;
- tcf_idr_release(*a, bind);
if (!ovr) {
+ tcf_idr_release(*a, bind);
ret = -EEXIST;
goto out_free;
}
--- a/net/sched/act_police.c
+++ b/net/sched/act_police.c
@@ -111,10 +111,9 @@ static int tcf_act_police_init(struct ne
if (ret)
return ret;
ret = ACT_P_CREATED;
- } else {
+ } else if (!ovr) {
tcf_idr_release(*a, bind);
- if (!ovr)
- return -EEXIST;
+ return -EEXIST;
}
police = to_police(*a);
@@ -195,8 +194,7 @@ static int tcf_act_police_init(struct ne
failure:
qdisc_put_rtab(P_tab);
qdisc_put_rtab(R_tab);
- if (ret == ACT_P_CREATED)
- tcf_idr_release(*a, bind);
+ tcf_idr_release(*a, bind);
return err;
}
--- a/net/sched/act_sample.c
+++ b/net/sched/act_sample.c
@@ -69,10 +69,9 @@ static int tcf_sample_init(struct net *n
if (ret)
return ret;
ret = ACT_P_CREATED;
- } else {
+ } else if (!ovr) {
tcf_idr_release(*a, bind);
- if (!ovr)
- return -EEXIST;
+ return -EEXIST;
}
s = to_sample(*a);
@@ -81,8 +80,7 @@ static int tcf_sample_init(struct net *n
s->psample_group_num = nla_get_u32(tb[TCA_SAMPLE_PSAMPLE_GROUP]);
psample_group = psample_group_get(net, s->psample_group_num);
if (!psample_group) {
- if (ret == ACT_P_CREATED)
- tcf_idr_release(*a, bind);
+ tcf_idr_release(*a, bind);
return -ENOMEM;
}
RCU_INIT_POINTER(s->psample_group, psample_group);
--- a/net/sched/act_simple.c
+++ b/net/sched/act_simple.c
@@ -127,9 +127,10 @@ static int tcf_simp_init(struct net *net
} else {
d = to_defact(*a);
- tcf_idr_release(*a, bind);
- if (!ovr)
+ if (!ovr) {
+ tcf_idr_release(*a, bind);
return -EEXIST;
+ }
reset_policy(d, tb[TCA_DEF_DATA], parm);
}
--- a/net/sched/act_skbedit.c
+++ b/net/sched/act_skbedit.c
@@ -172,9 +172,10 @@ static int tcf_skbedit_init(struct net *
ret = ACT_P_CREATED;
} else {
d = to_skbedit(*a);
- tcf_idr_release(*a, bind);
- if (!ovr)
+ if (!ovr) {
+ tcf_idr_release(*a, bind);
return -EEXIST;
+ }
}
spin_lock_bh(&d->tcf_lock);
--- a/net/sched/act_skbmod.c
+++ b/net/sched/act_skbmod.c
@@ -145,10 +145,9 @@ static int tcf_skbmod_init(struct net *n
return ret;
ret = ACT_P_CREATED;
- } else {
+ } else if (!ovr) {
tcf_idr_release(*a, bind);
- if (!ovr)
- return -EEXIST;
+ return -EEXIST;
}
d = to_skbmod(*a);
@@ -156,8 +155,7 @@ static int tcf_skbmod_init(struct net *n
ASSERT_RTNL();
p = kzalloc(sizeof(struct tcf_skbmod_params), GFP_KERNEL);
if (unlikely(!p)) {
- if (ret == ACT_P_CREATED)
- tcf_idr_release(*a, bind);
+ tcf_idr_release(*a, bind);
return -ENOMEM;
}
--- a/net/sched/act_tunnel_key.c
+++ b/net/sched/act_tunnel_key.c
@@ -329,12 +329,10 @@ static int tunnel_key_init(struct net *n
}
ret = ACT_P_CREATED;
- } else {
+ } else if (!ovr) {
tcf_idr_release(*a, bind);
- if (!ovr) {
- NL_SET_ERR_MSG(extack, "TC IDR already exists");
- return -EEXIST;
- }
+ NL_SET_ERR_MSG(extack, "TC IDR already exists");
+ return -EEXIST;
}
t = to_tunnel_key(*a);
@@ -342,8 +340,7 @@ static int tunnel_key_init(struct net *n
ASSERT_RTNL();
params_new = kzalloc(sizeof(*params_new), GFP_KERNEL);
if (unlikely(!params_new)) {
- if (ret == ACT_P_CREATED)
- tcf_idr_release(*a, bind);
+ tcf_idr_release(*a, bind);
NL_SET_ERR_MSG(extack, "Cannot allocate tunnel key parameters");
return -ENOMEM;
}
--- a/net/sched/act_vlan.c
+++ b/net/sched/act_vlan.c
@@ -187,10 +187,9 @@ static int tcf_vlan_init(struct net *net
return ret;
ret = ACT_P_CREATED;
- } else {
+ } else if (!ovr) {
tcf_idr_release(*a, bind);
- if (!ovr)
- return -EEXIST;
+ return -EEXIST;
}
v = to_vlan(*a);
@@ -198,8 +197,7 @@ static int tcf_vlan_init(struct net *net
ASSERT_RTNL();
p = kzalloc(sizeof(*p), GFP_KERNEL);
if (!p) {
- if (ret == ACT_P_CREATED)
- tcf_idr_release(*a, bind);
+ tcf_idr_release(*a, bind);
return -ENOMEM;
}