Re: CVE-2024-35906: drm/amd/display: Send DTBCLK disable message on first commit

[Michal Hocko]

CVE-2024-35881 to revert f341055b10bd ("drm/amd/display: Send DTBCLK
disable message on first commit") by 3a6a32b31a11 ("Revert
"drm/amd/display: Send DTBCLK disable message on first commit"") has
been filed as well.

Is this really intentional? Should both be rejected?

On Sun 19-05-24 10:35:20, Greg KH wrote:
> Description
> ===========
> 
> In the Linux kernel, the following vulnerability has been resolved:
> 
> drm/amd/display: Send DTBCLK disable message on first commit
> 
> [Why]
> Previous patch to allow DTBCLK disable didn't address boot case. Driver
> thinks DTBCLK is disabled by default, so we don't send disable message to
> PMFW. DTBCLK is then enabled at idle desktop on boot, burning power.
> 
> [How]
> Set dtbclk_en to true on boot so that disable message is sent during first
> commit.
> 
> The Linux kernel CVE team has assigned CVE-2024-35906 to this issue.
> 
> 
> Affected and fixed versions
> ===========================
> 
> 	Fixed in 6.8.5 with commit 0dab75b433ed
> 	Fixed in 6.9 with commit f341055b10bd
> 
> Please see https://www.kernel.org for a full list of currently supported
> kernel versions by the kernel community.
> 
> Unaffected versions might change over time as fixes are backported to
> older supported kernel versions.  The official CVE entry at
> 	https://cve.org/CVERecord/?id=CVE-2024-35906
> will be updated if fixes are backported, please check that for the most
> up to date information about this issue.
> 
> 
> Affected files
> ==============
> 
> The file(s) affected by this issue are:
> 	drivers/gpu/drm/amd/display/dc/clk_mgr/dcn35/dcn35_clk_mgr.c
> 
> 
> Mitigation
> ==========
> 
> The Linux kernel CVE team recommends that you update to the latest
> stable kernel version for this, and many other bugfixes.  Individual
> changes are never tested alone, but rather are part of a larger kernel
> release.  Cherry-picking individual commits is not recommended or
> supported by the Linux kernel community at all.  If however, updating to
> the latest release is impossible, the individual changes to resolve this
> issue can be found at these commits:
> 	https://git.kernel.org/stable/c/0dab75b433ed2480d57ae4f8f725186a46223e42
> 	https://git.kernel.org/stable/c/f341055b10bd8be55c3c995dff5f770b236b8ca9

-- 
Michal Hocko
SUSE Labs