[media] dvb-core: prevent some corruption the legacy ioctl
Quite a few of the ->diseqc_send_master_cmd() implementations don't
check cmd->msg_len so it can lead to memory corruption.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
diff --git a/drivers/media/dvb-core/dvb_frontend.c b/drivers/media/dvb-core/dvb_frontend.c
index b30ca59..842b9c8 100644
--- a/drivers/media/dvb-core/dvb_frontend.c
+++ b/drivers/media/dvb-core/dvb_frontend.c
@@ -2384,7 +2384,13 @@
case FE_DISEQC_SEND_MASTER_CMD:
if (fe->ops.diseqc_send_master_cmd) {
- err = fe->ops.diseqc_send_master_cmd(fe, (struct dvb_diseqc_master_cmd*) parg);
+ struct dvb_diseqc_master_cmd *cmd = parg;
+
+ if (cmd->msg_len > sizeof(cmd->msg)) {
+ err = -EINVAL;
+ break;
+ }
+ err = fe->ops.diseqc_send_master_cmd(fe, cmd);
fepriv->state = FESTATE_DISEQC;
fepriv->status = 0;
}