[PATCH net v2] net/sched: act_simple: fix parsing of TCA_DEF_DATA
From: Davide Caratti <hidden>
Date: 2018-06-08 03:02:55
use nla_strlcpy() to avoid copying data beyond the length of TCA_DEF_DATA
netlink attribute, in case it is less than SIMP_MAX_DATA and it does not
end with '\0' character.
v2: fix errors in the commit message, thanks Hangbin Liu
Fixes: fa1b1cff3d06 ("net_cls_act: Make act_simple use of netlink policy.")
Signed-off-by: Davide Caratti <redacted>
---
net/sched/act_simple.c | 15 ++++++---------
1 file changed, 6 insertions(+), 9 deletions(-)
diff --git a/net/sched/act_simple.c b/net/sched/act_simple.c
index 9618b4a83cee..98c4afe7c15b 100644
--- a/net/sched/act_simple.c
+++ b/net/sched/act_simple.c@@ -53,22 +53,22 @@ static void tcf_simp_release(struct tc_action *a) kfree(d->tcfd_defdata); } -static int alloc_defdata(struct tcf_defact *d, char *defdata) +static int alloc_defdata(struct tcf_defact *d, const struct nlattr *defdata) { d->tcfd_defdata = kzalloc(SIMP_MAX_DATA, GFP_KERNEL); if (unlikely(!d->tcfd_defdata)) return -ENOMEM; - strlcpy(d->tcfd_defdata, defdata, SIMP_MAX_DATA); + nla_strlcpy(d->tcfd_defdata, defdata, SIMP_MAX_DATA); return 0; } -static void reset_policy(struct tcf_defact *d, char *defdata, +static void reset_policy(struct tcf_defact *d, const struct nlattr *defdata, struct tc_defact *p) { spin_lock_bh(&d->tcf_lock); d->tcf_action = p->action; memset(d->tcfd_defdata, 0, SIMP_MAX_DATA); - strlcpy(d->tcfd_defdata, defdata, SIMP_MAX_DATA); + nla_strlcpy(d->tcfd_defdata, defdata, SIMP_MAX_DATA); spin_unlock_bh(&d->tcf_lock); }
@@ -87,7 +87,6 @@ static int tcf_simp_init(struct net *net, struct nlattr *nla, struct tcf_defact *d; bool exists = false; int ret = 0, err; - char *defdata; if (nla == NULL) return -EINVAL;
@@ -110,8 +109,6 @@ static int tcf_simp_init(struct net *net, struct nlattr *nla, return -EINVAL; } - defdata = nla_data(tb[TCA_DEF_DATA]); - if (!exists) { ret = tcf_idr_create(tn, parm->index, est, a, &act_simp_ops, bind, false);
@@ -119,7 +116,7 @@ static int tcf_simp_init(struct net *net, struct nlattr *nla, return ret; d = to_defact(*a); - ret = alloc_defdata(d, defdata); + ret = alloc_defdata(d, tb[TCA_DEF_DATA]); if (ret < 0) { tcf_idr_release(*a, bind); return ret;
@@ -133,7 +130,7 @@ static int tcf_simp_init(struct net *net, struct nlattr *nla, if (!ovr) return -EEXIST; - reset_policy(d, defdata, parm); + reset_policy(d, tb[TCA_DEF_DATA], parm); } if (ret == ACT_P_CREATED)
--
2.17.0