drm/amd/display: check dc_state_create_copy() for NULL in dm_suspend

dc_state_create_copy() can return NULL on allocation failure.
dm_suspend() only conditionally skips dm_gpureset_toggle_interrupts()
and continues execution, returning success.  dm_resume() then
dereferences the NULL cached_dc_state in link_enc_cfg_copy() and the
following dc_state->stream_count loop, crashing during GPU reset
recovery.

Return -ENOMEM immediately if the copy fails, so the caller aborts
suspend instead of leaving a NULL cached state for resume.

Fixes: 8092aa3ab8f7 ("drm/amd/display: Add null checker before passing variables")
Reviewed-by: George Zhang <george.zhang@amd.com>
Signed-off-by: Jiangshan Yi <yijiangshan@kylinos.cn>
Tested-by: Dan Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit 84b6d7932fdd2857795a257f9f258562a3cddcab)
Cc: stable@vger.kernel.org

0 files changed, 0 insertions, 0 deletions