This is a note to let you know that I've just added the patch titled
media: av7110: prevent underflow in write_ts_to_decoder()
to the 5.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
media-av7110-prevent-underflow-in-write_ts_to_decode.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 3e28baf39ea72c82bc8c707053879ee6a72e0e3c
Author: Dan Carpenter <error27@xxxxxxxxx>
Date: Tue Mar 7 11:00:23 2023 +0100
media: av7110: prevent underflow in write_ts_to_decoder()
[ Upstream commit eed9496a0501357aa326ddd6b71408189ed872eb ]
The buf[4] value comes from the user via ts_play(). It is a value in
the u8 range. The final length we pass to av7110_ipack_instant_repack()
is "len - (buf[4] + 1) - 4" so add a check to ensure that the length is
not negative. It's not clear that passing a negative len value does
anything bad necessarily, but it's not best practice.
With the new bounds checking the "if (!len)" condition is no longer
possible or required so remove that.
Fixes: fd46d16d602a ("V4L/DVB (11759): dvb-ttpci: Add TS replay capability")
Signed-off-by: Dan Carpenter <error27@xxxxxxxxx>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xxxxxxxxx>
Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/media/pci/ttpci/av7110_av.c b/drivers/media/pci/ttpci/av7110_av.c
index ea9f7d0058a21..e201d5a56bc65 100644
--- a/drivers/media/pci/ttpci/av7110_av.c
+++ b/drivers/media/pci/ttpci/av7110_av.c
@@ -822,10 +822,10 @@ static int write_ts_to_decoder(struct av7110 *av7110, int type, const u8 *buf, s
av7110_ipack_flush(ipack);
if (buf[3] & ADAPT_FIELD) {
+ if (buf[4] > len - 1 - 4)
+ return 0;
len -= buf[4] + 1;
buf += buf[4] + 1;
- if (!len)
- return 0;
}
av7110_ipack_instant_repack(buf + 4, len - 4, ipack);
