media: v4l2-tpg: array index could become negative

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>
This commit is contained in:
Hans Verkuil 2018-11-08 11:12:47 -05:00 committed by Mauro Carvalho Chehab
parent b01783f801
commit e5f71a27fa

View File

@ -1769,7 +1769,7 @@ 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); \