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

[Pengpeng Hou]

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@xxxxxxxxxxx>
---
 drivers/media/pci/ivtv/ivtv-vbi.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/media/pci/ivtv/ivtv-vbi.c b/drivers/media/pci/ivtv/ivtv-vbi.c
index ae7a00f..af086c4 100644
--- a/drivers/media/pci/ivtv/ivtv-vbi.c
+++ b/drivers/media/pci/ivtv/ivtv-vbi.c
@@ -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;
 	}