hi all, i would suggest converting this in to a more common for() loop. Programmers are bad in counting backwards. that kind of bug is common. re, wh ________________________________________ Von: kernel-janitors-owner@xxxxxxxxxxxxxxx <kernel-janitors-owner@xxxxxxxxxxxxxxx> im Auftrag von Colin King <colin.king@xxxxxxxxxxxxx> Gesendet: Mittwoch, 26. Februar 2020 20:58 An: Lee Jones; Daniel Thompson; Jingoo Han; Bartlomiej Zolnierkiewicz; Gyungoh Yoo; Bryan Wu; dri-devel@xxxxxxxxxxxxxxxxxxxxx; linux-fbdev@xxxxxxxxxxxxxxx Cc: kernel-janitors@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx Betreff: [PATCH][V2] backlight: sky81452: insure while loop does not allow negative array indexing From: Colin Ian King <colin.king@xxxxxxxxxxxxx> In the unlikely event that num_entry is zero, the while loop pre-decrements num_entry to cause negative array indexing into the array sources. Fix this by iterating only if num_entry >= 0. Addresses-Coverity: ("Out-of-bounds read") Fixes: f705806c9f35 ("backlight: Add support Skyworks SKY81452 backlight driver") Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx> --- V2: fix typo in commit subject line --- drivers/video/backlight/sky81452-backlight.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/video/backlight/sky81452-backlight.c b/drivers/video/backlight/sky81452-backlight.c index 2355f00f5773..f456930ce78e 100644 --- a/drivers/video/backlight/sky81452-backlight.c +++ b/drivers/video/backlight/sky81452-backlight.c @@ -200,7 +200,7 @@ static struct sky81452_bl_platform_data *sky81452_bl_parse_dt( } pdata->enable = 0; - while (--num_entry) + while (--num_entry >= 0) pdata->enable |= (1 << sources[num_entry]); int i; for(i=0;i<num_entry;i++) pdata->enable |= (1 << sources[i]); } -- 2.25.0