* [PATCH net v2] ipv4: Fix potential uninit variable access buf in __ip_make_skb()
@ 2023-04-10 1:45 Ziyang Xuan
2023-04-10 14:30 ` Willem de Bruijn
2023-04-19 14:02 ` Willem de Bruijn
0 siblings, 2 replies; 7+ messages in thread
From: Ziyang Xuan @ 2023-04-10 1:45 UTC (permalink / raw)
To: davem, dsahern, edumazet, kuba, pabeni, netdev
Like commit ea30388baebc ("ipv6: Fix an uninit variable access bug in
__ip6_make_skb()"). icmphdr does not in skb linear region under the
scenario of SOCK_RAW socket. Access icmp_hdr(skb)->type directly will
trigger the uninit variable access bug.
Use a local variable icmp_type to carry the correct value in different
scenarios.
Fixes: 96793b482540 ("[IPV4]: Add ICMPMsgStats MIB (RFC 4293)")
Signed-off-by: Ziyang Xuan <william.xuanziyang@huawei.com>
---
v2:
- Use sk->sk_type not sk->sk_socket->type.
---
net/ipv4/ip_output.c | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)
diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index 4e4e308c3230..21507c9ce0fc 100644
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -1570,9 +1570,15 @@ struct sk_buff *__ip_make_skb(struct sock *sk,
cork->dst = NULL;
skb_dst_set(skb, &rt->dst);
- if (iph->protocol == IPPROTO_ICMP)
- icmp_out_count(net, ((struct icmphdr *)
- skb_transport_header(skb))->type);
+ if (iph->protocol == IPPROTO_ICMP) {
+ u8 icmp_type;
+
+ if (sk->sk_type == SOCK_RAW && !inet_sk(sk)->hdrincl)
+ icmp_type = fl4->fl4_icmp_type;
+ else
+ icmp_type = icmp_hdr(skb)->type;
+ icmp_out_count(net, icmp_type);
+ }
ip_cork_release(cork);
out:
--
2.25.1
^ permalink raw reply related [flat|nested] 7+ messages in thread
* RE: [PATCH net v2] ipv4: Fix potential uninit variable access buf in __ip_make_skb()
2023-04-10 1:45 [PATCH net v2] ipv4: Fix potential uninit variable access buf in __ip_make_skb() Ziyang Xuan
@ 2023-04-10 14:30 ` Willem de Bruijn
2023-04-11 9:39 ` Ziyang Xuan (William)
2023-04-19 14:02 ` Willem de Bruijn
1 sibling, 1 reply; 7+ messages in thread
From: Willem de Bruijn @ 2023-04-10 14:30 UTC (permalink / raw)
To: Ziyang Xuan, davem, dsahern, edumazet, kuba, pabeni, netdev
Ziyang Xuan wrote:
> Like commit ea30388baebc ("ipv6: Fix an uninit variable access bug in
> __ip6_make_skb()"). icmphdr does not in skb linear region under the
> scenario of SOCK_RAW socket. Access icmp_hdr(skb)->type directly will
> trigger the uninit variable access bug.
>
> Use a local variable icmp_type to carry the correct value in different
> scenarios.
>
> Fixes: 96793b482540 ("[IPV4]: Add ICMPMsgStats MIB (RFC 4293)")
> Signed-off-by: Ziyang Xuan <william.xuanziyang@huawei.com>
> ---
> v2:
> - Use sk->sk_type not sk->sk_socket->type.
This is reached through
raw_sendmsg
raw_probe_proto_opt
ip_push_pending_frames
ip_finish_skb
__ip_make_skb
At this point, the icmp header has already been copied into skb linear
area. Is the isue that icmp_hdr/skb_transport_header is not set in
this path?
> ---
> net/ipv4/ip_output.c | 12 +++++++++---
> 1 file changed, 9 insertions(+), 3 deletions(-)
>
> diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
> index 4e4e308c3230..21507c9ce0fc 100644
> --- a/net/ipv4/ip_output.c
> +++ b/net/ipv4/ip_output.c
> @@ -1570,9 +1570,15 @@ struct sk_buff *__ip_make_skb(struct sock *sk,
> cork->dst = NULL;
> skb_dst_set(skb, &rt->dst);
>
> - if (iph->protocol == IPPROTO_ICMP)
> - icmp_out_count(net, ((struct icmphdr *)
> - skb_transport_header(skb))->type);
> + if (iph->protocol == IPPROTO_ICMP) {
> + u8 icmp_type;
> +
> + if (sk->sk_type == SOCK_RAW && !inet_sk(sk)->hdrincl)
> + icmp_type = fl4->fl4_icmp_type;
> + else
> + icmp_type = icmp_hdr(skb)->type;
> + icmp_out_count(net, icmp_type);
> + }
>
> ip_cork_release(cork);
> out:
> --
> 2.25.1
>
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH net v2] ipv4: Fix potential uninit variable access buf in __ip_make_skb()
2023-04-10 14:30 ` Willem de Bruijn
@ 2023-04-11 9:39 ` Ziyang Xuan (William)
2023-04-18 12:58 ` Ziyang Xuan (William)
0 siblings, 1 reply; 7+ messages in thread
From: Ziyang Xuan (William) @ 2023-04-11 9:39 UTC (permalink / raw)
To: Willem de Bruijn, davem, dsahern, edumazet, kuba, pabeni, netdev
> Ziyang Xuan wrote:
>> Like commit ea30388baebc ("ipv6: Fix an uninit variable access bug in
>> __ip6_make_skb()"). icmphdr does not in skb linear region under the
>> scenario of SOCK_RAW socket. Access icmp_hdr(skb)->type directly will
>> trigger the uninit variable access bug.
>>
>> Use a local variable icmp_type to carry the correct value in different
>> scenarios.
>>
>> Fixes: 96793b482540 ("[IPV4]: Add ICMPMsgStats MIB (RFC 4293)")
>> Signed-off-by: Ziyang Xuan <william.xuanziyang@huawei.com>
>> ---
>> v2:
>> - Use sk->sk_type not sk->sk_socket->type.
>
> This is reached through
>
> raw_sendmsg
> raw_probe_proto_opt
> ip_push_pending_frames
> ip_finish_skb
> __ip_make_skb
>
> At this point, the icmp header has already been copied into skb linear
> area. Is the isue that icmp_hdr/skb_transport_header is not set in
> this path?
>
Hello Willem,
raw_sendmsg
ip_append_data(..., transhdrlen==0, ...) // !inet->hdrincl
Parameter "transhdrlen" of ip_append_data() equals to 0 in raw_sendmsg()
not sizeof(struct icmphdr) as in ping_v4_sendmsg().
William Xuan.
>> ---
>> net/ipv4/ip_output.c | 12 +++++++++---
>> 1 file changed, 9 insertions(+), 3 deletions(-)
>>
>> diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
>> index 4e4e308c3230..21507c9ce0fc 100644
>> --- a/net/ipv4/ip_output.c
>> +++ b/net/ipv4/ip_output.c
>> @@ -1570,9 +1570,15 @@ struct sk_buff *__ip_make_skb(struct sock *sk,
>> cork->dst = NULL;
>> skb_dst_set(skb, &rt->dst);
>>
>> - if (iph->protocol == IPPROTO_ICMP)
>> - icmp_out_count(net, ((struct icmphdr *)
>> - skb_transport_header(skb))->type);
>> + if (iph->protocol == IPPROTO_ICMP) {
>> + u8 icmp_type;
>> +
>> + if (sk->sk_type == SOCK_RAW && !inet_sk(sk)->hdrincl)
>> + icmp_type = fl4->fl4_icmp_type;
>> + else
>> + icmp_type = icmp_hdr(skb)->type;
>> + icmp_out_count(net, icmp_type);
>> + }
>>
>> ip_cork_release(cork);
>> out:
>> --
>> 2.25.1
>>
>
>
> .
>
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH net v2] ipv4: Fix potential uninit variable access buf in __ip_make_skb()
2023-04-11 9:39 ` Ziyang Xuan (William)
@ 2023-04-18 12:58 ` Ziyang Xuan (William)
2023-04-18 14:28 ` Willem de Bruijn
0 siblings, 1 reply; 7+ messages in thread
From: Ziyang Xuan (William) @ 2023-04-18 12:58 UTC (permalink / raw)
To: Willem de Bruijn, davem, dsahern, edumazet, kuba, pabeni, netdev
>> Ziyang Xuan wrote:
>>> Like commit ea30388baebc ("ipv6: Fix an uninit variable access bug in
>>> __ip6_make_skb()"). icmphdr does not in skb linear region under the
>>> scenario of SOCK_RAW socket. Access icmp_hdr(skb)->type directly will
>>> trigger the uninit variable access bug.
>>>
>>> Use a local variable icmp_type to carry the correct value in different
>>> scenarios.
>>>
>>> Fixes: 96793b482540 ("[IPV4]: Add ICMPMsgStats MIB (RFC 4293)")
>>> Signed-off-by: Ziyang Xuan <william.xuanziyang@huawei.com>
>>> ---
>>> v2:
>>> - Use sk->sk_type not sk->sk_socket->type.
>>
>> This is reached through
>>
>> raw_sendmsg
>> raw_probe_proto_opt
>> ip_push_pending_frames
>> ip_finish_skb
>> __ip_make_skb
>>
>> At this point, the icmp header has already been copied into skb linear
>> area. Is the isue that icmp_hdr/skb_transport_header is not set in
>> this path?
>>
> Hello Willem,
>
> raw_sendmsg
> ip_append_data(..., transhdrlen==0, ...) // !inet->hdrincl
>
> Parameter "transhdrlen" of ip_append_data() equals to 0 in raw_sendmsg()
> not sizeof(struct icmphdr) as in ping_v4_sendmsg().
>
> William Xuan.
Hello Willem,
Does my answer answer your doubts?
William Xuan
>>> ---
>>> net/ipv4/ip_output.c | 12 +++++++++---
>>> 1 file changed, 9 insertions(+), 3 deletions(-)
>>>
>>> diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
>>> index 4e4e308c3230..21507c9ce0fc 100644
>>> --- a/net/ipv4/ip_output.c
>>> +++ b/net/ipv4/ip_output.c
>>> @@ -1570,9 +1570,15 @@ struct sk_buff *__ip_make_skb(struct sock *sk,
>>> cork->dst = NULL;
>>> skb_dst_set(skb, &rt->dst);
>>>
>>> - if (iph->protocol == IPPROTO_ICMP)
>>> - icmp_out_count(net, ((struct icmphdr *)
>>> - skb_transport_header(skb))->type);
>>> + if (iph->protocol == IPPROTO_ICMP) {
>>> + u8 icmp_type;
>>> +
>>> + if (sk->sk_type == SOCK_RAW && !inet_sk(sk)->hdrincl)
>>> + icmp_type = fl4->fl4_icmp_type;
>>> + else
>>> + icmp_type = icmp_hdr(skb)->type;
>>> + icmp_out_count(net, icmp_type);
>>> + }
>>>
>>> ip_cork_release(cork);
>>> out:
>>> --
>>> 2.25.1
>>>
>>
>>
>> .
>>
>
> .
>
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH net v2] ipv4: Fix potential uninit variable access buf in __ip_make_skb()
2023-04-18 12:58 ` Ziyang Xuan (William)
@ 2023-04-18 14:28 ` Willem de Bruijn
2023-04-19 9:41 ` Ziyang Xuan (William)
0 siblings, 1 reply; 7+ messages in thread
From: Willem de Bruijn @ 2023-04-18 14:28 UTC (permalink / raw)
To: Ziyang Xuan (William),
Willem de Bruijn, davem, dsahern, edumazet, kuba, pabeni, netdev
Ziyang Xuan (William) wrote:
> >> Ziyang Xuan wrote:
> >>> Like commit ea30388baebc ("ipv6: Fix an uninit variable access bug in
> >>> __ip6_make_skb()"). icmphdr does not in skb linear region under the
> >>> scenario of SOCK_RAW socket. Access icmp_hdr(skb)->type directly will
> >>> trigger the uninit variable access bug.
> >>>
> >>> Use a local variable icmp_type to carry the correct value in different
> >>> scenarios.
> >>>
> >>> Fixes: 96793b482540 ("[IPV4]: Add ICMPMsgStats MIB (RFC 4293)")
> >>> Signed-off-by: Ziyang Xuan <william.xuanziyang@huawei.com>
> >>> ---
> >>> v2:
> >>> - Use sk->sk_type not sk->sk_socket->type.
> >>
> >> This is reached through
> >>
> >> raw_sendmsg
> >> raw_probe_proto_opt
> >> ip_push_pending_frames
> >> ip_finish_skb
> >> __ip_make_skb
> >>
> >> At this point, the icmp header has already been copied into skb linear
> >> area. Is the isue that icmp_hdr/skb_transport_header is not set in
> >> this path?
> >>
> > Hello Willem,
> >
> > raw_sendmsg
> > ip_append_data(..., transhdrlen==0, ...) // !inet->hdrincl
> >
> > Parameter "transhdrlen" of ip_append_data() equals to 0 in raw_sendmsg()
> > not sizeof(struct icmphdr) as in ping_v4_sendmsg().
> >
> > William Xuan.
> Hello Willem,
>
> Does my answer answer your doubts?
Thanks. Yes, that explains. Would you mind adding a comment to that
effect. Sommething like
/* for such sockets, transport hlen is zero and icmp_hdr incorrect */
if (sk->sk_type == SOCK_RAW && !inet_sk(sk)->hdrincl)
I missed your previous response, William. Sorry about that.
> William Xuan
> >>> ---
> >>> net/ipv4/ip_output.c | 12 +++++++++---
> >>> 1 file changed, 9 insertions(+), 3 deletions(-)
> >>>
> >>> diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
> >>> index 4e4e308c3230..21507c9ce0fc 100644
> >>> --- a/net/ipv4/ip_output.c
> >>> +++ b/net/ipv4/ip_output.c
> >>> @@ -1570,9 +1570,15 @@ struct sk_buff *__ip_make_skb(struct sock *sk,
> >>> cork->dst = NULL;
> >>> skb_dst_set(skb, &rt->dst);
> >>>
> >>> - if (iph->protocol == IPPROTO_ICMP)
> >>> - icmp_out_count(net, ((struct icmphdr *)
> >>> - skb_transport_header(skb))->type);
> >>> + if (iph->protocol == IPPROTO_ICMP) {
> >>> + u8 icmp_type;
> >>> +
> >>> + if (sk->sk_type == SOCK_RAW && !inet_sk(sk)->hdrincl)
> >>> + icmp_type = fl4->fl4_icmp_type;
> >>> + else
> >>> + icmp_type = icmp_hdr(skb)->type;
> >>> + icmp_out_count(net, icmp_type);
> >>> + }
> >>>
> >>> ip_cork_release(cork);
> >>> out:
> >>> --
> >>> 2.25.1
> >>>
> >>
> >>
> >> .
> >>
> >
> > .
> >
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH net v2] ipv4: Fix potential uninit variable access buf in __ip_make_skb()
2023-04-18 14:28 ` Willem de Bruijn
@ 2023-04-19 9:41 ` Ziyang Xuan (William)
0 siblings, 0 replies; 7+ messages in thread
From: Ziyang Xuan (William) @ 2023-04-19 9:41 UTC (permalink / raw)
To: Willem de Bruijn, davem, dsahern, edumazet, kuba, pabeni, netdev
> Ziyang Xuan (William) wrote:
>>>> Ziyang Xuan wrote:
>>>>> Like commit ea30388baebc ("ipv6: Fix an uninit variable access bug in
>>>>> __ip6_make_skb()"). icmphdr does not in skb linear region under the
>>>>> scenario of SOCK_RAW socket. Access icmp_hdr(skb)->type directly will
>>>>> trigger the uninit variable access bug.
>>>>>
>>>>> Use a local variable icmp_type to carry the correct value in different
>>>>> scenarios.
>>>>>
>>>>> Fixes: 96793b482540 ("[IPV4]: Add ICMPMsgStats MIB (RFC 4293)")
>>>>> Signed-off-by: Ziyang Xuan <william.xuanziyang@huawei.com>
>>>>> ---
>>>>> v2:
>>>>> - Use sk->sk_type not sk->sk_socket->type.
>>>>
>>>> This is reached through
>>>>
>>>> raw_sendmsg
>>>> raw_probe_proto_opt
>>>> ip_push_pending_frames
>>>> ip_finish_skb
>>>> __ip_make_skb
>>>>
>>>> At this point, the icmp header has already been copied into skb linear
>>>> area. Is the isue that icmp_hdr/skb_transport_header is not set in
>>>> this path?
>>>>
>>> Hello Willem,
>>>
>>> raw_sendmsg
>>> ip_append_data(..., transhdrlen==0, ...) // !inet->hdrincl
>>>
>>> Parameter "transhdrlen" of ip_append_data() equals to 0 in raw_sendmsg()
>>> not sizeof(struct icmphdr) as in ping_v4_sendmsg().
>>>
>>> William Xuan.
>> Hello Willem,
>>
>> Does my answer answer your doubts?
>
> Thanks. Yes, that explains. Would you mind adding a comment to that
> effect. Sommething like
>
> /* for such sockets, transport hlen is zero and icmp_hdr incorrect */
> if (sk->sk_type == SOCK_RAW && !inet_sk(sk)->hdrincl)
>
That is fine. It will make other developers understand the logic here quickly.
> I missed your previous response, William. Sorry about that.
>
>> William Xuan
>>>>> ---
>>>>> net/ipv4/ip_output.c | 12 +++++++++---
>>>>> 1 file changed, 9 insertions(+), 3 deletions(-)
>>>>>
>>>>> diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
>>>>> index 4e4e308c3230..21507c9ce0fc 100644
>>>>> --- a/net/ipv4/ip_output.c
>>>>> +++ b/net/ipv4/ip_output.c
>>>>> @@ -1570,9 +1570,15 @@ struct sk_buff *__ip_make_skb(struct sock *sk,
>>>>> cork->dst = NULL;
>>>>> skb_dst_set(skb, &rt->dst);
>>>>>
>>>>> - if (iph->protocol == IPPROTO_ICMP)
>>>>> - icmp_out_count(net, ((struct icmphdr *)
>>>>> - skb_transport_header(skb))->type);
>>>>> + if (iph->protocol == IPPROTO_ICMP) {
>>>>> + u8 icmp_type;
>>>>> +
>>>>> + if (sk->sk_type == SOCK_RAW && !inet_sk(sk)->hdrincl)
>>>>> + icmp_type = fl4->fl4_icmp_type;
>>>>> + else
>>>>> + icmp_type = icmp_hdr(skb)->type;
>>>>> + icmp_out_count(net, icmp_type);
>>>>> + }
>>>>>
>>>>> ip_cork_release(cork);
>>>>> out:
>>>>> --
>>>>> 2.25.1
>>>>>
>>>>
>>>>
>>>> .
>>>>
>>>
>>> .
>>>
>
>
> .
>
^ permalink raw reply [flat|nested] 7+ messages in thread
* RE: [PATCH net v2] ipv4: Fix potential uninit variable access buf in __ip_make_skb()
2023-04-10 1:45 [PATCH net v2] ipv4: Fix potential uninit variable access buf in __ip_make_skb() Ziyang Xuan
2023-04-10 14:30 ` Willem de Bruijn
@ 2023-04-19 14:02 ` Willem de Bruijn
1 sibling, 0 replies; 7+ messages in thread
From: Willem de Bruijn @ 2023-04-19 14:02 UTC (permalink / raw)
To: Ziyang Xuan, davem, dsahern, edumazet, kuba, pabeni, netdev
Ziyang Xuan wrote:
> Like commit ea30388baebc ("ipv6: Fix an uninit variable access bug in
> __ip6_make_skb()"). icmphdr does not in skb linear region under the
> scenario of SOCK_RAW socket. Access icmp_hdr(skb)->type directly will
> trigger the uninit variable access bug.
>
> Use a local variable icmp_type to carry the correct value in different
> scenarios.
>
> Fixes: 96793b482540 ("[IPV4]: Add ICMPMsgStats MIB (RFC 4293)")
> Signed-off-by: Ziyang Xuan <william.xuanziyang@huawei.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2023-04-19 14:02 UTC | newest]
Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2023-04-10 1:45 [PATCH net v2] ipv4: Fix potential uninit variable access buf in __ip_make_skb() Ziyang Xuan
2023-04-10 14:30 ` Willem de Bruijn
2023-04-11 9:39 ` Ziyang Xuan (William)
2023-04-18 12:58 ` Ziyang Xuan (William)
2023-04-18 14:28 ` Willem de Bruijn
2023-04-19 9:41 ` Ziyang Xuan (William)
2023-04-19 14:02 ` Willem de Bruijn
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