Re: CVE-2024-46808: drm/amd/display: Add missing NULL pointer check within dpcd_extend_address_range

[Greg Kroah-Hartman]

On Mon, Sep 30, 2024 at 08:58:41PM +0200, Michal Koutný wrote:
> Hello.
> 
> On Fri, Sep 27, 2024 at 02:36:13PM GMT, Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
> > In the Linux kernel, the following vulnerability has been resolved:
> > 
> > drm/amd/display: Add missing NULL pointer check within dpcd_extend_address_range
> > 
> > [Why & How]
> > ASSERT if return NULL from kcalloc.
> > 
> > The Linux kernel CVE team has assigned CVE-2024-46808 to this issue.
> 
> This is not a good CVE fix since it'd bring the system down for users
> with panic_on_warn=1 anyway. (I wasn't able to `make
> drivers/gpu/drm/amd/display/dc/link/protocols/link_dpcd.i` but I assume
> the ASSERTs expand to one of the WARN_ONs, feel free to correct me.)

It's a good fix for those without that option enabled :)

> It'd need graceful handling of the kcalloc failure.

Agreed, it could be fixed better.

thanks,

greg k-h