FAILED: patch "[PATCH] drm/amd/display: prevent null pointer access" failed to apply to 5.9-stable tree

[<gregkh@xxxxxxxxxxxxxxxxxxx>]

The patch below does not apply to the 5.9-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@xxxxxxxxxxxxxxx>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

>From 140b2ef1c28d3f5a5fc767368eaa8b45afc5bf1f Mon Sep 17 00:00:00 2001
From: Dmytro Laktyushkin <Dmytro.Laktyushkin@xxxxxxx>
Date: Thu, 15 Oct 2020 14:49:56 -0400
Subject: [PATCH] drm/amd/display: prevent null pointer access

Prevent null pointer access when checking odm tree.

Signed-off-by: Dmytro Laktyushkin <Dmytro.Laktyushkin@xxxxxxx>
Acked-by: Aurabindo Pillai <aurabindo.pillai@xxxxxxx>
Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>

diff --git a/drivers/gpu/drm/amd/display/dc/dcn30/dcn30_resource.c b/drivers/gpu/drm/amd/display/dc/dcn30/dcn30_resource.c
index 24fb39a11e5d..2455d210ccf6 100644
--- a/drivers/gpu/drm/amd/display/dc/dcn30/dcn30_resource.c
+++ b/drivers/gpu/drm/amd/display/dc/dcn30/dcn30_resource.c
@@ -2105,12 +2105,12 @@ static bool dcn30_internal_validate_bw(
 
 		if (split[i]) {
 			if (odm) {
-				if (split[i] == 4 && old_pipe->next_odm_pipe->next_odm_pipe)
+				if (split[i] == 4 && old_pipe->next_odm_pipe && old_pipe->next_odm_pipe->next_odm_pipe)
 					old_index = old_pipe->next_odm_pipe->next_odm_pipe->pipe_idx;
 				else if (old_pipe->next_odm_pipe)
 					old_index = old_pipe->next_odm_pipe->pipe_idx;
 			} else {
-				if (split[i] == 4 && old_pipe->bottom_pipe->bottom_pipe &&
+				if (split[i] == 4 && old_pipe->bottom_pipe && old_pipe->bottom_pipe->bottom_pipe &&
 						old_pipe->bottom_pipe->bottom_pipe->plane_state == old_pipe->plane_state)
 					old_index = old_pipe->bottom_pipe->bottom_pipe->pipe_idx;
 				else if (old_pipe->bottom_pipe &&
@@ -2150,10 +2150,12 @@ static bool dcn30_internal_validate_bw(
 				goto validate_fail;
 			newly_split[pipe_4to1->pipe_idx] = true;
 
-			if (odm && old_pipe->next_odm_pipe->next_odm_pipe->next_odm_pipe)
+			if (odm && old_pipe->next_odm_pipe && old_pipe->next_odm_pipe->next_odm_pipe
+					&& old_pipe->next_odm_pipe->next_odm_pipe->next_odm_pipe)
 				old_index = old_pipe->next_odm_pipe->next_odm_pipe->next_odm_pipe->pipe_idx;
-			else if (!odm && old_pipe->bottom_pipe->bottom_pipe->bottom_pipe &&
-						old_pipe->bottom_pipe->bottom_pipe->bottom_pipe->plane_state == old_pipe->plane_state)
+			else if (!odm && old_pipe->bottom_pipe && old_pipe->bottom_pipe->bottom_pipe &&
+					old_pipe->bottom_pipe->bottom_pipe->bottom_pipe &&
+					old_pipe->bottom_pipe->bottom_pipe->bottom_pipe->plane_state == old_pipe->plane_state)
 				old_index = old_pipe->bottom_pipe->bottom_pipe->bottom_pipe->pipe_idx;
 			else
 				old_index = -1;