[PATCH 1/1] fbdev: atyfb: Fix buffer overflow

[Denis Arefev]

The value LCD_MISC_CNTL is used in the 'aty_st_lcd()' function to
calculate an index for accessing an array element of size 9.
This may cause a buffer overflow.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Denis Arefev <arefev@xxxxxxxxx>
---
 drivers/video/fbdev/aty/atyfb_base.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/video/fbdev/aty/atyfb_base.c b/drivers/video/fbdev/aty/atyfb_base.c
index 210fd3ac18a4..93eb5eb6042b 100644
--- a/drivers/video/fbdev/aty/atyfb_base.c
+++ b/drivers/video/fbdev/aty/atyfb_base.c
@@ -149,6 +149,8 @@ static const u32 lt_lcd_regs[] = {
 void aty_st_lcd(int index, u32 val, const struct atyfb_par *par)
 {
 	if (M64_HAS(LT_LCD_REGS)) {
+		if ((u32)index >= ARRAY_SIZE(lt_lcd_regs))
+			return;
 		aty_st_le32(lt_lcd_regs[index], val, par);
 	} else {
 		unsigned long temp;
@@ -164,6 +166,8 @@ void aty_st_lcd(int index, u32 val, const struct atyfb_par *par)
 u32 aty_ld_lcd(int index, const struct atyfb_par *par)
 {
 	if (M64_HAS(LT_LCD_REGS)) {
+		if ((u32)index >= ARRAY_SIZE(lt_lcd_regs))
+			return 0;
 		return aty_ld_le32(lt_lcd_regs[index], par);
 	} else {
 		unsigned long temp;
-- 
2.43.0