| Message ID | 20230703110842.590282-1-linma@zju.edu.cn (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 30c45b5361d39b4b793780ffac5538090b9e2eb1 |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [v1] net/sched: act_pedit: Add size check for TCA_PEDIT_PARMS_EX | expand |
On 03/07/2023 08:08, Lin Ma wrote: > 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@zju.edu.cn> LGTM, Reviewed-by: Pedro Tammela <pctammela@mojatatu.com> > --- > 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 b562fc2bb5b1..1ef8fcfa9997 100644 > --- a/net/sched/act_pedit.c > +++ b/net/sched/act_pedit.c > @@ -29,6 +29,7 @@ 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 }, > }; >
Hello: This patch was applied to netdev/net.git (main) by Paolo Abeni <pabeni@redhat.com>: On Mon, 3 Jul 2023 19:08:42 +0800 you wrote: > 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 > > [...] Here is the summary with links: - [v1] net/sched: act_pedit: Add size check for TCA_PEDIT_PARMS_EX https://git.kernel.org/netdev/net/c/30c45b5361d3 You are awesome, thank you!
diff --git a/net/sched/act_pedit.c b/net/sched/act_pedit.c index b562fc2bb5b1..1ef8fcfa9997 100644 --- a/net/sched/act_pedit.c +++ b/net/sched/act_pedit.c @@ -29,6 +29,7 @@ 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 }, };
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@zju.edu.cn> --- net/sched/act_pedit.c | 1 + 1 file changed, 1 insertion(+)