From b21535727613dfd00368fc37c4d14bd47e8b5543 Mon Sep 17 00:00:00 2001 From: Hans Verkuil Date: Thu, 8 Nov 2018 11:12:47 -0500 Subject: [PATCH] media: v4l2-tpg: array index could become negative commit e5f71a27fa12c1a1b02ad478a568e76260f1815e upstream. text[s] is a signed char, so using that as index into the font8x16 array can result in negative indices. Cast it to u8 to be safe. Signed-off-by: Hans Verkuil Reported-by: syzbot+ccf0a61ed12f2a7313ee@syzkaller.appspotmail.com Cc: # for v4.7 and up Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Greg Kroah-Hartman --- drivers/media/common/v4l2-tpg/v4l2-tpg-core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/media/common/v4l2-tpg/v4l2-tpg-core.c b/drivers/media/common/v4l2-tpg/v4l2-tpg-core.c index 1f463f4c3024..d2f72f3635aa 100644 --- a/drivers/media/common/v4l2-tpg/v4l2-tpg-core.c +++ b/drivers/media/common/v4l2-tpg/v4l2-tpg-core.c @@ -1618,7 +1618,7 @@ typedef struct { u16 __; u8 _; } __packed x24; unsigned s; \ \ for (s = 0; s < len; s++) { \ - u8 chr = font8x16[text[s] * 16 + line]; \ + u8 chr = font8x16[(u8)text[s] * 16 + line]; \ \ if (hdiv == 2 && tpg->hflip) { \ pos[3] = (chr & (0x01 << 6) ? fg : bg); \ -- 2.20.1