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author | Lin Ma <linma@zju.edu.cn> | 2023-07-03 19:08:42 +0800 |
---|---|---|
committer | Paolo Abeni <pabeni@redhat.com> | 2023-07-04 10:31:38 +0200 |
commit | 30c45b5361d39b4b793780ffac5538090b9e2eb1 (patch) | |
tree | 95f2b5b0bbd2cef0e97f449bb92d39ec417f6f88 | |
parent | 2c5d234d7f55e4ba7f3ee00fb9452ac7c97b4a46 (diff) | |
download | linux-stable-30c45b5361d39b4b793780ffac5538090b9e2eb1.tar.gz linux-stable-30c45b5361d39b4b793780ffac5538090b9e2eb1.tar.bz2 linux-stable-30c45b5361d39b4b793780ffac5538090b9e2eb1.zip |
net/sched: act_pedit: Add size check for TCA_PEDIT_PARMS_EX
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>
Reviewed-by: Pedro Tammela <pctammela@mojatatu.com>
Link: https://lore.kernel.org/r/20230703110842.590282-1-linma@zju.edu.cn
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
-rw-r--r-- | net/sched/act_pedit.c | 1 |
1 files changed, 1 insertions, 0 deletions
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 }, }; |