From: Dan Carpenter error27@gmail.com
[ 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@gmail.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 --- drivers/media/pci/ttpci/av7110_av.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/media/pci/ttpci/av7110_av.c b/drivers/media/pci/ttpci/av7110_av.c index 2aa4ba675194e..43b780aadf5fe 100644 --- a/drivers/media/pci/ttpci/av7110_av.c +++ b/drivers/media/pci/ttpci/av7110_av.c @@ -836,10 +836,10 @@ 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);