From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dan Carpenter Date: Sat, 06 Jun 2015 16:55:22 +0000 Subject: [PATCH] [media] dvb-core: prevent some corruption the legacy ioctl Message-Id: <20150606165521.GB28331@mwanda> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Mauro Carvalho Chehab Cc: Shuah Khan , Akihiro Tsukada , Antti Palosaari , linux-media@vger.kernel.org, kernel-janitors@vger.kernel.org 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 --- I don't think it ever makes sense for ->msg_len to be longer than ->msg but I am a newbie to this code. diff --git a/drivers/media/dvb-core/dvb_frontend.c b/drivers/media/dvb-core/dvb_frontend.c index a894d4c..aa6b48f 100644 --- a/drivers/media/dvb-core/dvb_frontend.c +++ b/drivers/media/dvb-core/dvb_frontend.c @@ -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; }