media: ivtv: stop VBI start-code scan before short tail

compress_sliced_buf() scans one byte at a time while testing a four-byte
VBI start code.  The final iterations can read beyond the remaining
buffer tail.

Stop the scan once fewer than four bytes remain.

Signed-off-by: Pengpeng Hou <pengpeng@iscas.ac.cn>
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>
This commit is contained in:
Pengpeng Hou 2026-06-30 15:19:33 +08:00 committed by Hans Verkuil
parent bf533acaaa
commit f373cf17fb

View File

@ -330,7 +330,7 @@ static u32 compress_sliced_buf(struct ivtv *itv, u32 line, u8 *buf, u32 size, u8
unsigned lines = 0;
/* find the first valid line */
for (i = 0; i < size; i++, buf++) {
for (i = 0; i + 3 < size; i++, buf++) {
if (buf[0] == 0xff && !buf[1] && !buf[2] && buf[3] == sav)
break;
}