media: v4l2-jpeg: correct the skip count in jpeg_parse_app14_data

[ Upstream commit 41959c4f973b837a12061b84d3a436fc64c73a30 ]

The curr pointer has advanced 14 bytes in jpeg_parse_app14_data.
1. jpeg_get_word_be(stream), it goes forward 2 bytes.
2. jpeg_skip(stream, 11), it goes forward 11 bytes.
3. jpeg_get_byte(stream), it goes forward 1 bytes.

so the remain bytes of this segment should be (lp - 2 - 11 - 1),
but not (lp - 2 - 11).

if driver skip 1 extra bytes, the following parsing may go wrong.

Fixes: b8035f7988a8 ("media: Add parsing for APP14 data segment in jpeg helpers")
Signed-off-by: Ming Qian <ming.qian@nxp.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/media/v4l2-core/v4l2-jpeg.c b/drivers/media/v4l2-core/v4l2-jpeg.c
index c2513b7..75c2af7 100644 (file)
--- a/drivers/media/v4l2-core/v4l2-jpeg.c
+++ b/drivers/media/v4l2-core/v4l2-jpeg.c
@@ -474,7 +474,7 @@ static int jpeg_parse_app14_data(struct jpeg_stream *stream,
        *tf = ret;
 
        /* skip the rest of the segment, this ensures at least it is complete */
-       skip = lp - 2 - 11;
+       skip = lp - 2 - 11 - 1;
        return jpeg_skip(stream, skip);
 }