2018-12-26 03:54:11

by Kangjie Lu

Subject: [PATCH] ipset: fix a missing check of nla_parse

When nla_parse fails, we should not use the results (the first
argument). The fix checks if it fails, and if so, returns its error code
upstream.

Signed-off-by: Kangjie Lu <[email protected]>
---
net/netfilter/ipset/ip_set_core.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/net/netfilter/ipset/ip_set_core.c b/net/netfilter/ipset/ip_set_core.c
index 1577f2f76060..4dc8057cff02 100644
--- a/net/netfilter/ipset/ip_set_core.c
+++ b/net/netfilter/ipset/ip_set_core.c
@@ -1531,8 +1531,10 @@ call_ad(struct sock *ctnl, struct sk_buff *skb, struct ip_set *set,
memcpy(&errmsg->msg, nlh, nlh->nlmsg_len);
cmdattr = (void *)&errmsg->msg + min_len;

- nla_parse(cda, IPSET_ATTR_CMD_MAX, cmdattr,
+ ret = nla_parse(cda, IPSET_ATTR_CMD_MAX, cmdattr,
nlh->nlmsg_len - min_len, ip_set_adt_policy, NULL);
+ if (ret)
+ return ret;

errline = nla_data(cda[IPSET_ATTR_LINENO]);

--
2.17.2 (Apple Git-113)

2018-12-26 09:18:43

by Kirill Tkhai

Subject: Re: [PATCH] ipset: fix a missing check of nla_parse

On 26.12.2018 06:50, Kangjie Lu wrote:
> When nla_parse fails, we should not use the results (the first
> argument). The fix checks if it fails, and if so, returns its error code
> upstream.
>
> Signed-off-by: Kangjie Lu <[email protected]>
> ---
> net/netfilter/ipset/ip_set_core.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/net/netfilter/ipset/ip_set_core.c b/net/netfilter/ipset/ip_set_core.c
> index 1577f2f76060..4dc8057cff02 100644
> --- a/net/netfilter/ipset/ip_set_core.c
> +++ b/net/netfilter/ipset/ip_set_core.c
> @@ -1531,8 +1531,10 @@ call_ad(struct sock *ctnl, struct sk_buff *skb, struct ip_set *set,
> memcpy(&errmsg->msg, nlh, nlh->nlmsg_len);
> cmdattr = (void *)&errmsg->msg + min_len;
>
> - nla_parse(cda, IPSET_ATTR_CMD_MAX, cmdattr,
> + ret = nla_parse(cda, IPSET_ATTR_CMD_MAX, cmdattr,
> nlh->nlmsg_len - min_len, ip_set_adt_policy, NULL);
> + if (ret)
> + return ret;

In this function above nlmsg_new() allocates skb2, but I don't see, where you free it here.

>
> errline = nla_data(cda[IPSET_ATTR_LINENO]);
>
>

2019-01-09 22:47:09

by Pablo Neira Ayuso

Subject: Re: [PATCH] ipset: fix a missing check of nla_parse

On Wed, Dec 26, 2018 at 12:16:25PM +0300, Kirill Tkhai wrote:
> On 26.12.2018 06:50, Kangjie Lu wrote:
> > When nla_parse fails, we should not use the results (the first
> > argument). The fix checks if it fails, and if so, returns its error code
> > upstream.
> >
> > Signed-off-by: Kangjie Lu <[email protected]>
> > ---
> > net/netfilter/ipset/ip_set_core.c | 4 +++-
> > 1 file changed, 3 insertions(+), 1 deletion(-)
> >
> > diff --git a/net/netfilter/ipset/ip_set_core.c b/net/netfilter/ipset/ip_set_core.c
> > index 1577f2f76060..4dc8057cff02 100644
> > --- a/net/netfilter/ipset/ip_set_core.c
> > +++ b/net/netfilter/ipset/ip_set_core.c
> > @@ -1531,8 +1531,10 @@ call_ad(struct sock *ctnl, struct sk_buff *skb, struct ip_set *set,
> > memcpy(&errmsg->msg, nlh, nlh->nlmsg_len);
> > cmdattr = (void *)&errmsg->msg + min_len;
> >
> > - nla_parse(cda, IPSET_ATTR_CMD_MAX, cmdattr,
> > + ret = nla_parse(cda, IPSET_ATTR_CMD_MAX, cmdattr,
> > nlh->nlmsg_len - min_len, ip_set_adt_policy, NULL);

@Kangjie: nitpick, could you align this line below? ie.

ret = nla_parse(cda, IPSET_ATTR_CMD_MAX, cmdattr,
nlh->nlmsg_len - min_len, ip_set_adt_policy,
NULL);

> > + if (ret)
> > + return ret;
>
> In this function above nlmsg_new() allocates skb2, but I don't see, where you free it here.

netlink_unicast() is responsible for releasing this skb2.

> > errline = nla_data(cda[IPSET_ATTR_LINENO]);
> >
> >

2019-01-10 08:55:34

by Kirill Tkhai

Subject: Re: [PATCH] ipset: fix a missing check of nla_parse

On 10.01.2019 01:43, Pablo Neira Ayuso wrote:
> On Wed, Dec 26, 2018 at 12:16:25PM +0300, Kirill Tkhai wrote:
>> On 26.12.2018 06:50, Kangjie Lu wrote:
>>> When nla_parse fails, we should not use the results (the first
>>> argument). The fix checks if it fails, and if so, returns its error code
>>> upstream.
>>>
>>> Signed-off-by: Kangjie Lu <[email protected]>
>>> ---
>>> net/netfilter/ipset/ip_set_core.c | 4 +++-
>>> 1 file changed, 3 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/net/netfilter/ipset/ip_set_core.c b/net/netfilter/ipset/ip_set_core.c
>>> index 1577f2f76060..4dc8057cff02 100644
>>> --- a/net/netfilter/ipset/ip_set_core.c
>>> +++ b/net/netfilter/ipset/ip_set_core.c
>>> @@ -1531,8 +1531,10 @@ call_ad(struct sock *ctnl, struct sk_buff *skb, struct ip_set *set,
>>> memcpy(&errmsg->msg, nlh, nlh->nlmsg_len);
>>> cmdattr = (void *)&errmsg->msg + min_len;
>>>
>>> - nla_parse(cda, IPSET_ATTR_CMD_MAX, cmdattr,
>>> + ret = nla_parse(cda, IPSET_ATTR_CMD_MAX, cmdattr,
>>> nlh->nlmsg_len - min_len, ip_set_adt_policy, NULL);
>
> @Kangjie: nitpick, could you align this line below? ie.
>
> ret = nla_parse(cda, IPSET_ATTR_CMD_MAX, cmdattr,
> nlh->nlmsg_len - min_len, ip_set_adt_policy,
> NULL);
>
>>> + if (ret)
>>> + return ret;
>>
>> In this function above nlmsg_new() allocates skb2, but I don't see, where you free it here.
>
> netlink_unicast() is responsible for releasing this skb2.

We return earlier at "if (ret)", so netlink_unicast() is not called.

>>> errline = nla_data(cda[IPSET_ATTR_LINENO]);

Kirill