4.20-stable review patch. If anyone has any objections, please let me know.
------------------
From: Hans Verkuil hverkuil-cisco@xs4all.nl
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 hverkuil-cisco@xs4all.nl Reported-by: syzbot+ccf0a61ed12f2a7313ee@syzkaller.appspotmail.com Cc: stable@vger.kernel.org # for v4.7 and up Signed-off-by: Mauro Carvalho Chehab mchehab+samsung@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/media/common/v4l2-tpg/v4l2-tpg-core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/media/common/v4l2-tpg/v4l2-tpg-core.c +++ b/drivers/media/common/v4l2-tpg/v4l2-tpg-core.c @@ -1769,7 +1769,7 @@ typedef struct { u16 __; u8 _; } __packe 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); \