Re: CVE-2020-35519 Linux kernel: x25_bind out-of-bounds read

[Salvatore Bonaccorso <carnil () debian org>]

Hi,

On Wed, Mar 17, 2021 at 05:14:57PM -0400, Sasha Levin wrote:
> On Thu, Mar 18, 2021 at 01:20:18AM +0530, Rohit Keshri wrote:
> > Hello Team,
> >
> > An out-of-bounds (OOB) memory access flaw was found in x25_bind in
> > net/x25/af_x25.c in the Linux kernel. A bounds check failure allows a local
> > attacker with a user account on the system to gain access to out-of-bounds
> > memory, leading to a system crash or a leak of internal kernel information.
> > The highest threat from this vulnerability is to confidentiality,
> > integrity, as well as system availability.
> >
> > 'CVE-2020-35519' was assigned by Red Hat.
>
> This mail doesn't even mention where/how this is fixed. Is this
> 6ee50c8e262a ("net/x25: prevent a couple of overflows")?
>
> If so, it's already fixed in all stable kernels.
>
> How can the issue cause a leak btw?

Just as additional reference: I think this goes back to this report:
https://www.openwall.com/lists/oss-security/2020/11/15/2 

In upstream this was fixed then if the above is correct in

        v4.4.248
        v4.9.248
        v4.14.211
        v4.19.162
        v5.4.82
        v5.9.13
        v5.10-rc7

Regards,
Salvatore