ttusb-dec: buffer overflow in ioctl

commit f2e323ec96077642d397bb1c355def536d489d16 upstream.

We need to add a limit check here so we don't overflow the buffer.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
[bwh: Backported to 3.2: adjust filename]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/drivers/media/dvb/ttusb-dec/ttusbdecfe.c b/drivers/media/dvb/ttusb-dec/ttusbdecfe.c
index 21260aa..852870b 100644 (file)
--- a/drivers/media/dvb/ttusb-dec/ttusbdecfe.c
+++ b/drivers/media/dvb/ttusb-dec/ttusbdecfe.c
@@ -154,6 +154,9 @@ static int ttusbdecfe_dvbs_diseqc_send_master_cmd(struct dvb_frontend* fe, struc
                   0x00, 0x00, 0x00, 0x00,
                   0x00, 0x00 };
 
+       if (cmd->msg_len > sizeof(b) - 4)
+               return -EINVAL;
+
        memcpy(&b[4], cmd->msg, cmd->msg_len);
 
        state->config->send_command(fe, 0x72,