[media] dvb-core: prevent some corruption the legacy ioctl
Commit Message
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>
---
I don't think it ever makes sense for ->msg_len to be longer than ->msg
but I am a newbie to this code.
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@@ -2403,7 +2403,13 @@ static int dvb_frontend_ioctl_legacy(struct file *file,
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;
}