| Message ID | 20180922134648.GA7027@mwanda |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
| Series | [net] net: sched: act_ipt: check for underflow in __tcf_ipt_init() | expand |
From: Dan Carpenter <dan.carpenter@oracle.com> Date: Sat, 22 Sep 2018 16:46:48 +0300 > If "td->u.target_size" is larger than sizeof(struct xt_entry_target) we > return -EINVAL. But we don't check whether it's smaller than > sizeof(struct xt_entry_target) and that could lead to an out of bounds > read. > > Fixes: 7ba699c604ab ("[NET_SCHED]: Convert actions from rtnetlink to new netlink API") > Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Applied.
diff --git a/net/sched/act_ipt.c b/net/sched/act_ipt.c index 1efbfb10b1fc..8af6c11d2482 100644 --- a/net/sched/act_ipt.c +++ b/net/sched/act_ipt.c @@ -135,7 +135,7 @@ static int __tcf_ipt_init(struct net *net, unsigned int id, struct nlattr *nla, } td = (struct xt_entry_target *)nla_data(tb[TCA_IPT_TARG]); - if (nla_len(tb[TCA_IPT_TARG]) < td->u.target_size) { + if (nla_len(tb[TCA_IPT_TARG]) != td->u.target_size) { if (exists) tcf_idr_release(*a, bind); else
If "td->u.target_size" is larger than sizeof(struct xt_entry_target) we return -EINVAL. But we don't check whether it's smaller than sizeof(struct xt_entry_target) and that could lead to an out of bounds read. Fixes: 7ba699c604ab ("[NET_SCHED]: Convert actions from rtnetlink to new netlink API") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> --- I haven't tested this. Please review carefully.