From: Lin Ma <linma@xxxxxxxxxx>
[ Upstream commit 30c45b5361d39b4b793780ffac5538090b9e2eb1 ]
The attribute TCA_PEDIT_PARMS_EX is not be included in pedit_policy and
one malicious user could fake a TCA_PEDIT_PARMS_EX whose length is
smaller than the intended sizeof(struct tc_pedit). Hence, the
dereference in tcf_pedit_init() could access dirty heap data.
static int tcf_pedit_init(...)
{
// ...
pattr = tb[TCA_PEDIT_PARMS]; // TCA_PEDIT_PARMS is included
if (!pattr)
pattr = tb[TCA_PEDIT_PARMS_EX]; // but this is not
// ...
parm = nla_data(pattr);
index = parm->index; // parm is able to be smaller than 4 bytes
// and this dereference gets dirty skb_buff
// data created in netlink_sendmsg
}
This commit adds TCA_PEDIT_PARMS_EX length in pedit_policy which avoid
the above case, just like the TCA_PEDIT_PARMS.
Fixes: 71d0ed7079df ("net/act_pedit: Support using offset relative to the conventional network headers")
Signed-off-by: Lin Ma <linma@xxxxxxxxxx>
Reviewed-by: Pedro Tammela <pctammela@xxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20230703110842.590282-1-linma@xxxxxxxxxx
Signed-off-by: Paolo Abeni <pabeni@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
net/sched/act_pedit.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/net/sched/act_pedit.c b/net/sched/act_pedit.c
index db0d3bff19eba..a44101b2f4419 100644
--- a/net/sched/act_pedit.c
+++ b/net/sched/act_pedit.c
@@ -26,6 +26,7 @@ static struct tc_action_ops act_pedit_ops;
static const struct nla_policy pedit_policy[TCA_PEDIT_MAX + 1] = {
[TCA_PEDIT_PARMS] = { .len = sizeof(struct tc_pedit) },
+ [TCA_PEDIT_PARMS_EX] = { .len = sizeof(struct tc_pedit) },
[TCA_PEDIT_KEYS_EX] = { .type = NLA_NESTED },
};
--
2.39.2
