[SRU][J][PATCH 0/1] CVE-2024-26661

[Hui Wang]

[Impact]

In "u32 otg_inst = pipe_ctx->stream_res.tg->inst;", the
pipe_ctx->stream_res.tg could be NULL in some cases.

[Backport]

To cleanly cherry-pick the patch to jammy kernel, at least 2
prerequisite patches are needed, they are 6f0ef80a00ad ("
drm/amd/display: Fix ABM pipe/backlight issues when change backlight")
and 0210dcf253d8 ("drm/amd/display: Pass pwrseq inst for backlight
and ABM"), each of them will introduce significant change and most of
change is not relevant to this CVE issue.
>From the commit header, the patch is to resolve the possible NULL ptr
issue of pipe_ctx->stream_res.tg, hence I just backport the relevant
part and drop the conflict part. This backported patch could resolve
the possible NULL issue and keep the other part unchanged.

[Fix]

Noble:  Fixed
Jammy:  Backported from mainline linux-v6.8-rc4 to jammy, see explanation in [Backport]
Focal:  Not affected
Bionic: Not affected
Xenial: Not affected

[Test Case]

Building test passed.

And Tested the patched kernel on a Lenovo laptop with AMD cpu, the
graphic worked as well as before, the system could boot to Desktop,
I could ran applications under Desktop.

[Where problems could occur]

The change impacts amdgpu driver, if there is regression, it will be
in the graphic, something like abnormal situation on graphic. But the
likely of regression is very low, the change is straightforward and
simple, and I tested the patched kernel on an AMD laptop, everything
worked well.

Srinivasan Shanmugam (1):
  drm/amd/display: Add NULL test for 'timing generator' in
    'dcn21_set_pipe()'

 drivers/gpu/drm/amd/display/dc/dcn21/dcn21_hwseq.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

-- 
2.34.1