From 7bcfd3a8c0a6b05899e7dc9a14962a63deb20510 Mon Sep 17 00:00:00 2001
From: Haowen Bai <baihaowen@meizu.com>
Date: Fri, 1 Apr 2022 11:41:16 +0800
Subject: video: fbdev: sis: fix potential NULL dereference in
 sisfb_post_sis300()
Git-commit: d1d608ce78b3fc330938faaa1f70a91cf20c03a9
Patch-mainline: v5.18-rc5
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

Do no access bios[] if it's NULL.

Signed-off-by: Haowen Bai <baihaowen@meizu.com>
Signed-off-by: Helge Deller <deller@gmx.de>
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
 drivers/video/fbdev/sis/sis_main.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/video/fbdev/sis/sis_main.c b/drivers/video/fbdev/sis/sis_main.c
index 742f62986b80..f28fd69d5eb7 100644
--- a/drivers/video/fbdev/sis/sis_main.c
+++ b/drivers/video/fbdev/sis/sis_main.c
@@ -4463,7 +4463,7 @@ static void sisfb_post_sis300(struct pci_dev *pdev)
 		SiS_SetReg(SISCR, 0x37, 0x02);
 		SiS_SetReg(SISPART2, 0x00, 0x1c);
 		v4 = 0x00; v5 = 0x00; v6 = 0x10;
-		if(ivideo->SiS_Pr.UseROM) {
+		if (ivideo->SiS_Pr.UseROM && bios) {
 			v4 = bios[0xf5];
 			v5 = bios[0xf6];
 			v6 = bios[0xf7];
-- 
2.38.1