2020-06-08 07:55:23

by Geliang Tang

Subject: [PATCH] mptcp: bugfix for RM_ADDR option parsing

In MPTCPOPT_RM_ADDR option parsing, the pointer "ptr" pointed to the
"Subtype" octet, the pointer "ptr+1" pointed to the "Address ID" octet:

+-------+-------+---------------+
|Subtype|(resvd)| Address ID |
+-------+-------+---------------+
| |
ptr ptr+1

We should set mp_opt->rm_id to the value of "ptr+1", not "ptr". This patch
will fix this bug.

Signed-off-by: Geliang Tang <[email protected]>
---
net/mptcp/options.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/net/mptcp/options.c b/net/mptcp/options.c
index 01f1f4cf4902..490b92534afc 100644
--- a/net/mptcp/options.c
+++ b/net/mptcp/options.c
@@ -273,6 +273,8 @@ static void mptcp_parse_option(const struct sk_buff *skb,
if (opsize != TCPOLEN_MPTCP_RM_ADDR_BASE)
break;

+ ptr++;
+
mp_opt->rm_addr = 1;
mp_opt->rm_id = *ptr++;
pr_debug("RM_ADDR: id=%d", mp_opt->rm_id);
--
2.17.1

2020-06-08 10:12:57

by Matthieu Baerts

Subject: Re: [PATCH] mptcp: bugfix for RM_ADDR option parsing

Hi Geliang,

On 08/06/2020 09:48, Geliang Tang wrote:
> In MPTCPOPT_RM_ADDR option parsing, the pointer "ptr" pointed to the
> "Subtype" octet, the pointer "ptr+1" pointed to the "Address ID" octet:
>
> +-------+-------+---------------+
> |Subtype|(resvd)| Address ID |
> +-------+-------+---------------+
> | |
> ptr ptr+1
>
> We should set mp_opt->rm_id to the value of "ptr+1", not "ptr". This patch
> will fix this bug.

Thank you for the patch, good catch!
Indeed "ptr" should be incremented.

Because this is a bug-fix for net, may you clearly indicate that in the
subject to help -net maintainers please? [PATCH net v2]

Also, may you add a "Fixes" tag as well as it is for -net ? I guess it
should be:

Fixes: 3df523ab582c ("mptcp: Add ADD_ADDR handling")

The rest is good!

Cheers,
Matt
--
Matthieu Baerts | R&D Engineer
[email protected]
Tessares SA | Hybrid Access Solutions
http://www.tessares.net
1 Avenue Jean Monnet, 1348 Louvain-la-Neuve, Belgium

2020-06-08 11:04:02

by Geliang Tang

Subject: Re: [PATCH] mptcp: bugfix for RM_ADDR option parsing

On Mon, Jun 08, 2020 at 12:10:23PM +0200, Matthieu Baerts wrote:
> Hi Geliang,
>
> On 08/06/2020 09:48, Geliang Tang wrote:
> > In MPTCPOPT_RM_ADDR option parsing, the pointer "ptr" pointed to the
> > "Subtype" octet, the pointer "ptr+1" pointed to the "Address ID" octet:
> >
> > +-------+-------+---------------+
> > |Subtype|(resvd)| Address ID |
> > +-------+-------+---------------+
> > | |
> > ptr ptr+1
> >
> > We should set mp_opt->rm_id to the value of "ptr+1", not "ptr". This patch
> > will fix this bug.
>
> Thank you for the patch, good catch!
> Indeed "ptr" should be incremented.
>
> Because this is a bug-fix for net, may you clearly indicate that in the
> subject to help -net maintainers please? [PATCH net v2]
>
> Also, may you add a "Fixes" tag as well as it is for -net ? I guess it
> should be:
>
> Fixes: 3df523ab582c ("mptcp: Add ADD_ADDR handling")
>
> The rest is good!
>
> Cheers,
> Matt
> --
> Matthieu Baerts | R&D Engineer
> [email protected]
> Tessares SA | Hybrid Access Solutions
> http://www.tessares.net
> 1 Avenue Jean Monnet, 1348 Louvain-la-Neuve, Belgium

Hi Matt,

Thanks for your reply.

I have already resend patch v2 to you.

-Geliang