From 12ad1925084352a97b926c7b6e3ab27e8207428c Mon Sep 17 00:00:00 2001
From: Harshvardhan Jha <harshvardhan.jha@oracle.com>
Date: Fri, 9 Jul 2021 13:09:59 +0530
Subject: drm/gma500: Fix end of loop tests for list_for_each_entry
Git-commit: ea9a897b8affa0f7b4c90182b785dded74e434aa
Patch-mainline: v5.15-rc1
References: jsc#PED-1166 jsc#PED-1168 jsc#PED-1170 jsc#PED-1218 jsc#PED-1220 jsc#PED-1222 jsc#PED-1223 jsc#PED-1225
The list_for_each_entry() iterator, "connector" in this code, can never be
NULL. If we exit the loop without finding the correct connector then
"connector" points invalid memory that is an offset from the list head.
This will eventually lead to memory corruption and presumably a kernel
crash.
Fixes: 9bd81acdb648 ("gma500: Convert Oaktrail to work with new output handling")
Signed-off-by: Harshvardhan Jha <harshvardhan.jha@oracle.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210709073959.11443-1-harshvardhan.jha@oracle.com
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
drivers/gpu/drm/gma500/oaktrail_lvds.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/gpu/drm/gma500/oaktrail_lvds.c
+++ b/drivers/gpu/drm/gma500/oaktrail_lvds.c
@@ -117,7 +117,7 @@
break;
}
- if (!connector) {
+ if (list_entry_is_head(connector, &mode_config->connector_list, head)) {
DRM_ERROR("Couldn't find connector when setting mode");
gma_power_end(dev);
return;