Re: Vulnerability Disclosure in net/

[Michael Nazzareno Trimarchi <michael@amarulasolutions.com>]

Hi Fabio

On Thu, May 26, 2022 at 2:13 PM Fabio Estevam <festevam@gmail.com> wrote:
>
> Hi Ramon,
>
> On Wed, May 25, 2022 at 11:46 PM Ramon Fried <rfried.dev@gmail.com> wrote:
>
> > Hi Nicolas,
> > Thanks for the research.
> > I have read your description thoroughly, very interesting.
> > I will implement fixes to the findings.
>
> Is it enough to add the check below?
>
> --- a/net/net.c
> +++ b/net/net.c
> @@ -906,6 +906,9 @@ static struct ip_udp_hdr *__net_defragment(struct
> ip_udp_hdr *ip, int *lenp)
>         uchar *indata = (uchar *)ip;
>         int offset8, start, len, done = 0;
>         u16 ip_off = ntohs(ip->ip_off);
> +
> +       if (ip->ip_len < 28)
> +               return NULL;
>
If you comment on it up or nobody will remember what is 28 tomorrow

Michael


>         /* payload starts after IP header, this fragment is in there */
>         payload = (struct hole *)(pkt_buff + IP_HDR_SIZE);



-- 
Michael Nazzareno Trimarchi
Co-Founder & Chief Executive Officer
M. +39 347 913 2170
michael@amarulasolutions.com
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