From b719a9c15d52d4f56bdea8241a5d90fd9197ce99 Mon Sep 17 00:00:00 2001
From: Mario Limonciello <mario.limonciello@amd.com>
Date: Tue, 28 Nov 2023 18:35:09 -0600
Subject: drm/amd/display: Fix NULL pointer dereference at hibernate
Git-commit: b719a9c15d52d4f56bdea8241a5d90fd9197ce99
Patch-mainline: v6.8-rc1
References: git-fixes CVE-2023-52460 bsc#1220319

During hibernate sequence the source context might not have a clk_mgr.
So don't use it to look for DML2 support.

Link: https://gitlab.freedesktop.org/drm/amd/-/issues/2980
Fixes: 7966f319c66d ("drm/amd/display: Introduce DML2")
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
 drivers/gpu/drm/amd/display/dc/core/dc_resource.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_resource.c b/drivers/gpu/drm/amd/display/dc/core/dc_resource.c
index f3a9fdd2340d..e1c02527d04a 100644
--- a/drivers/gpu/drm/amd/display/dc/core/dc_resource.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc_resource.c
@@ -4554,7 +4554,7 @@ void dc_resource_state_copy_construct(
 	struct dml2_context *dml2 = NULL;
 
 	// Need to preserve allocated dml2 context
-	if (src_ctx->clk_mgr->ctx->dc->debug.using_dml2)
+	if (src_ctx->clk_mgr && src_ctx->clk_mgr->ctx->dc->debug.using_dml2)
 		dml2 = dst_ctx->bw_ctx.dml2;
 #endif
 
@@ -4562,7 +4562,7 @@ void dc_resource_state_copy_construct(
 
 #ifdef CONFIG_DRM_AMD_DC_FP
 	// Preserve allocated dml2 context
-	if (src_ctx->clk_mgr->ctx->dc->debug.using_dml2)
+	if (src_ctx->clk_mgr && src_ctx->clk_mgr->ctx->dc->debug.using_dml2)
 		dst_ctx->bw_ctx.dml2 = dml2;
 #endif
 
-- 
2.43.0